SPPA 4030 Speech Science. Stephen M. Tasko Ph.D. CCC-SLP. Topic 1: The Speech Chain. Learning Objectives Outline the general sequence of biological/physical events that occur from speech formulation to speech perception. - PowerPoint PPT Presentation
TRANSCRIPT
SPPA 4030Speech Science
Stephen M Tasko PhD CCC-SLP
Topic 1 The Speech Chain
Learning Objectivesbull Outline the general sequence of
biologicalphysical events that occur from speech formulation to speech perception
bull Describe the different types of information content embedded within the speech signal
bull Know and describe the different branches of physics and biology used to inform basic mechanisms of speech production and perception
The Speech Chain (Denes amp Pinson 1993)
What information is embedded in the speech signal
bull Phonetic informationbull Affective informationbull Personal informationbull Transmittal informationbull Diagnostic Information
Branches of science employed to understand speech communication
bull Complex gt one frequency componentbull Aperiodic Does not repeat itselfbull Frequency components are not systematically
relatedbull May be ndash Continuousndash Transient
Aperiodic sounds Graphic appearance
bull Time domainndash no repeating pattern of pressure change
bull Frequency domainndash the spectrum is dense ndash No ldquopicket fencerdquo
bull Auditory impression sounds lsquonoisyrsquo
Aperiodic sounds Graphic appearance
From Hillenbrand
>
Analysis of complex wavesbull Waves can be summedbull Complex waves are the sum of simple wavesbull Fourier French Mathematician
ndash Any complex waveform may be formed by summing sinusoids of various frequency amplitude and phase
bull Fourier Analysisndash Provides a unique (only one) solution for a given sound signalndash Is reflected in the amplitude and phase spectrum of the signalndash Reveals the building blocks of complex waves which are sinusoids
Learning Objectives
bull Draw and differentiate the waveform and the waveform envelope
bull Draw and differentiate the amplitude spectrum the phase spectrum and the spectrum envelope
bull Differential between short-term spectra and long-term average spectra
The ldquoenveloperdquo of a sound wave
bull Waveform envelopendash imaginary smooth line that follows the peak of the
amplitude of a sound pressure waveformbull Spectrum envelopendash Imaginary smooth line drawn on top of the
amplitude spectrum
Waveform envelope
From Hillenbrand
Waveform envelope
Time
>
Spectrum envelope
Frequency
Ampl
itude
Thought Question
Can an aperiodic and complex periodic sound have identical
spectrum envelopes
Amplitude Spectrum Window Size
bull ldquoshort-termrdquo vs ldquolong-term averagerdquo amplitude spectrum
ldquoInstantaneousrdquo Amplitude Spectra
(Long Term) Average Amplitude Spectrum
Learning Objectivesbull Describe how the amplitude spectrum and the spectrogram are
relatedbull Identify the axis units of the spectrogrambull Provide some advantages of the spectrogram over the
amplitude spectrumbull Distinguish between a wide band and narrow band spectrogram
and outline the different information each providesbull Distinguish between a harmonic and a formant on a
spectrogrambull Be able to draw stylized (highly simplified) spectrograms based
on spectra and spectrum envelopes
The Spectrogram
Rotate90 degrees
F
AF
A
Building a spectrogram
Rotate it so thatThe amplitude isComing out of thepage
F
A This is really narrow because it is a slice in time
F
Time
Building a spectrogram
Dark bands= amplitudePeaks
Time
Freq
uenc
y
Building a spectrogram
Two main types of spectrograms
bull Narrow-band spectrogramsndash Akin to amplitude spectrums ldquolined uprdquondash Frequency resolution is really sharp
bull Wide-band spectrogramsndash Akin to spectrum envelopes ldquolined uprdquondash Frequency resolution not so sharp
Highlights harmonic structure
Highlights spectrum envelope
Wide vs Narrow Band Spectrograms
Learning Objectives
bull Define an acoustic filterbull Draw and label a frequency response curvebull Draw and differentiate different types of acoustic
filtersbull Define terms such as cutoff frequency center
frequency roll off rate gain and bandwidthbull Define and draw a basic filter system and relate that
to the source-filter theory of speech production
What is an ldquoAcousticrdquo Filter
bull holds back (attenuates) certain sounds and lets other sounds through - selective
Why might we be interested in filters
bull Human vocal tract acts like a frequency selective acoustic filter
bull Human auditory system behaves as a frequency selective filter
bull helps us understand how speech is produced and perceived
Kinds of frequency selective filters
Low-pass filtersndash Lets low frequencies ldquopass throughrdquo and attenuates high
frequencies
High-pass filtersndash Lets high frequencies ldquopass throughrdquo and attenuates low
frequencies
Band-pass filtersndash Lets a particular frequency range ldquopass throughrdquo and
attenuates other frequencies
Low Pass Filters
Frequencylow high
Gai
n
+
-
High Pass Filters
Frequencylow high
Gai
n
+
-
Band Pass Filter
Frequencylow high
Gai
n
+
-
Frequency Response Curve (FRC)
Frequencylow high
Gai
n
+
-
Center frequency
lower cutofffrequency
upper cutoff frequency
passband
3 dB
Operation of a filter on a signal
NOTE Amplitude spectrum describes a soundFrequency response curve describes a filter
Learning Objectivesbull Define resonance free and forced vibrationbull Describe how the pendulum and spring mass models can
help explain resonancebull Outline how mass and stiffness influences the resonant
frequency of a mass spring systembull Outline how acoustic resonators behave like acoustic filtersbull Calculate resonant frequencies of a uniform tube based on
its physical dimensionsbull Describe how the wavelength of the sound determines the
resonant frequency of tube
Free vibration
bull objects tend to vibrate at a characteristic or resonant frequency (RF)
Forced vibration
bull A vibrating system can force a nearby system into vibration
bull The efficiency with which this is accomplished is related to the similarity in the resonant frequency (RF) of the two systems
Forced vibration
bull If the RF of the two systems are the same the amplitude of forced vibration will be large
bull If the RF of the two systems are quite different the amplitude of forced vibration will be small or nonexistent
Resonance refers to
bull The tendency for an object to vibrate at a particular frequency or frequencies
bull The ability of a vibrating system to force another system into vibration
Back to the mass spring model
bull Vibratory frequency of the mass spring determined byndash Massndash Stiffness of the spring
httpphetcoloradoeduensimulationmass-spring-lab
Acoustic Resonance
bull Ideas from mechanical resonance also applies to acoustic systems
bull Acoustic chambers will transmit sound frequencies with more or less efficiency depending upon the physical characteristics
bull Therefore they act as filters passing through (and even amplifying) some frequencies and attentuating others
Acoustic Resonance
bull And since they act as filters they have most of the same features of a filter even though we might use different names
bull Center frequency is often termed the resonant frequency
bull Frequency response curve often termed the resonance curve
Helmholtz Resonator
Actions of a Helmholtz Resonator
Stephen M Tasko
Other Acoustic Resonators Tube Resonators
bull Uniform tubes Factors that influence resonancendash Lengthndash Cross-sectional area along its lengthndash Whether it is closed at either or both ends
Uniform tube closed at one end
Uniform tube closed at one end
Stephen M Tasko
Uniform tube closed at one end
First resonance or formant
F1 = c4lWhere
c=speed of sound (35000 cmsec)l = length of the tube
males ~ 175 cmfemales ~ 14 cm
Higher resonantformant frequencies are odd multiples of F1
For examplebull F1 = (c4l )1
bull F2 = (c4l )3
bull F3 = (c4l )5
Comparing Helmholtz and tube resonators
Resonator Features
Sharply tuned Broadly tuned
Resonator Features
An example of the resonance characteristics of the human vocal tract
Frequency
Gain
SPPA 4030 Speech Science
Topic 1 The Speech Chain
The Speech Chain (Denes amp Pinson 1993)
What information is embedded in the speech signal
Branches of science employed to understand speech communication
Physical Quantities Review An Independent Learning Activity
Assignment 1
Topic 2 The Source-Filter Theory of Speech Production An Intr
Producing Speech
Source-Filter Theory of Speech Production
Vocal tract is a tube that can vary its shape
Source Filter Theory
Same Source Different Filter
Different Source Same Filters
Different Source Same Filters (Human)
Different Source Same Filters (Human) (2)
Different Source Same Filters (Human) (3)
Different Source Same Filters (Human) (4)
Different Source Same Filters (Non-Human)
Different Source Same Filters (Non-Human) (2)
Different Source Same Filters (Non-Human) If it quacks like a
Source Filter Theory Applied Alaryngeal Speech
Source-Filter Theory Applied Esophageal Insufflation Test
Source-Filter Theory Applied Tracheoesophageal (TE) Speech
Source Filter Theory Applied The Talkbox
Source-Filter Theory Applied The Talkbox
Topic 3 A Brief Review of Physical Acoustics
Spring Mass Model
What is sound
Sound-conducting media
Model of air molecule vibration (Time 1)
Model of air molecule vibration (Time 2)
Model of air molecule vibration (Time 3)
Model of air molecule vibration (Time 4)
Model of air molecule vibration (Time 5)
Model of air molecule vibration
Wave action of molecular motion
Amplitude waveform
Amplitude waveform (2)
Where is pressure in this model
Pressure waveform
Measuring Sound
Measuring Sound Signal Amplitude
Measuring Sound Signal Amplitude (2)
What units do we use to measure signal amplitude
Brief Review The decibel scale
Absolute vs relative measurement
Typical reference values
Howeverhellip
Linear vs logarithmic
Linear vs logarithmic (2)
Logarithmic Scale
Logarithmic Scale (2)
Combining the idea of logarithmic and relativehellip
Intensity vs Pressure
Extending the formula to pressure
Measuring Sound Frequencyperiod
Measuring Sound Frequencyperiod (2)
Phase Uniform Circular Motion
Initiating a sound waves that differ only in phase
Spatial variation in pressure wave
Spatial variation in pressure wave
Spatial variation in pressure wave (2)
Relation between frequency and wavelength
Learning Objectives
Graphic representation of sound
Same sound different graphs
Classification of sounds
Simple periodic sound
Simple periodic sound Graphic appearance
Complex periodic sounds
Complex periodic sounds Graphic appearance
Complex periodic sounds Graphic appearance (2)
Glottal Source
Amplitude vs Phase Spectrum
Amplitude vs Phase Spectrum (2)
(Complex) Aperiodic sounds
Aperiodic sounds Graphic appearance
Aperiodic sounds Graphic appearance (2)
Analysis of complex waves
Learning Objectives (2)
The ldquoenveloperdquo of a sound wave
Waveform envelope
Waveform envelope (2)
Spectrum envelope
Thought Question
Amplitude Spectrum Window Size
ldquoInstantaneousrdquo Amplitude Spectra
(Long Term) Average Amplitude Spectrum
Slide 90
Learning Objectives (3)
The Spectrogram
Building a spectrogram
Building a spectrogram
Building a spectrogram (2)
Two main types of spectrograms
Wide vs Narrow Band Spectrograms
Learning Objectives (4)
What is an ldquoAcousticrdquo Filter
Why might we be interested in filters
Kinds of frequency selective filters
Low Pass Filters
High Pass Filters
Band Pass Filter
Frequency Response Curve (FRC)
Operation of a filter on a signal
Learning Objectives (5)
Free vibration
Forced vibration
Forced vibration (2)
Resonance refers to
Back to the mass spring model
Acoustic Resonance
Acoustic Resonance (2)
Helmholtz Resonator
Actions of a Helmholtz Resonator
Other Acoustic Resonators Tube Resonators
Uniform tube closed at one end
Uniform tube closed at one end (2)
Uniform tube closed at one end
Comparing Helmholtz and tube resonators
Slide 122
Slide 123
Topic 1 The Speech Chain
Learning Objectivesbull Outline the general sequence of
biologicalphysical events that occur from speech formulation to speech perception
bull Describe the different types of information content embedded within the speech signal
bull Know and describe the different branches of physics and biology used to inform basic mechanisms of speech production and perception
The Speech Chain (Denes amp Pinson 1993)
What information is embedded in the speech signal
bull Phonetic informationbull Affective informationbull Personal informationbull Transmittal informationbull Diagnostic Information
Branches of science employed to understand speech communication
bull Complex gt one frequency componentbull Aperiodic Does not repeat itselfbull Frequency components are not systematically
relatedbull May be ndash Continuousndash Transient
Aperiodic sounds Graphic appearance
bull Time domainndash no repeating pattern of pressure change
bull Frequency domainndash the spectrum is dense ndash No ldquopicket fencerdquo
bull Auditory impression sounds lsquonoisyrsquo
Aperiodic sounds Graphic appearance
From Hillenbrand
>
Analysis of complex wavesbull Waves can be summedbull Complex waves are the sum of simple wavesbull Fourier French Mathematician
ndash Any complex waveform may be formed by summing sinusoids of various frequency amplitude and phase
bull Fourier Analysisndash Provides a unique (only one) solution for a given sound signalndash Is reflected in the amplitude and phase spectrum of the signalndash Reveals the building blocks of complex waves which are sinusoids
Learning Objectives
bull Draw and differentiate the waveform and the waveform envelope
bull Draw and differentiate the amplitude spectrum the phase spectrum and the spectrum envelope
bull Differential between short-term spectra and long-term average spectra
The ldquoenveloperdquo of a sound wave
bull Waveform envelopendash imaginary smooth line that follows the peak of the
amplitude of a sound pressure waveformbull Spectrum envelopendash Imaginary smooth line drawn on top of the
amplitude spectrum
Waveform envelope
From Hillenbrand
Waveform envelope
Time
>
Spectrum envelope
Frequency
Ampl
itude
Thought Question
Can an aperiodic and complex periodic sound have identical
spectrum envelopes
Amplitude Spectrum Window Size
bull ldquoshort-termrdquo vs ldquolong-term averagerdquo amplitude spectrum
ldquoInstantaneousrdquo Amplitude Spectra
(Long Term) Average Amplitude Spectrum
Learning Objectivesbull Describe how the amplitude spectrum and the spectrogram are
relatedbull Identify the axis units of the spectrogrambull Provide some advantages of the spectrogram over the
amplitude spectrumbull Distinguish between a wide band and narrow band spectrogram
and outline the different information each providesbull Distinguish between a harmonic and a formant on a
spectrogrambull Be able to draw stylized (highly simplified) spectrograms based
on spectra and spectrum envelopes
The Spectrogram
Rotate90 degrees
F
AF
A
Building a spectrogram
Rotate it so thatThe amplitude isComing out of thepage
F
A This is really narrow because it is a slice in time
F
Time
Building a spectrogram
Dark bands= amplitudePeaks
Time
Freq
uenc
y
Building a spectrogram
Two main types of spectrograms
bull Narrow-band spectrogramsndash Akin to amplitude spectrums ldquolined uprdquondash Frequency resolution is really sharp
bull Wide-band spectrogramsndash Akin to spectrum envelopes ldquolined uprdquondash Frequency resolution not so sharp
Highlights harmonic structure
Highlights spectrum envelope
Wide vs Narrow Band Spectrograms
Learning Objectives
bull Define an acoustic filterbull Draw and label a frequency response curvebull Draw and differentiate different types of acoustic
filtersbull Define terms such as cutoff frequency center
frequency roll off rate gain and bandwidthbull Define and draw a basic filter system and relate that
to the source-filter theory of speech production
What is an ldquoAcousticrdquo Filter
bull holds back (attenuates) certain sounds and lets other sounds through - selective
Why might we be interested in filters
bull Human vocal tract acts like a frequency selective acoustic filter
bull Human auditory system behaves as a frequency selective filter
bull helps us understand how speech is produced and perceived
Kinds of frequency selective filters
Low-pass filtersndash Lets low frequencies ldquopass throughrdquo and attenuates high
frequencies
High-pass filtersndash Lets high frequencies ldquopass throughrdquo and attenuates low
frequencies
Band-pass filtersndash Lets a particular frequency range ldquopass throughrdquo and
attenuates other frequencies
Low Pass Filters
Frequencylow high
Gai
n
+
-
High Pass Filters
Frequencylow high
Gai
n
+
-
Band Pass Filter
Frequencylow high
Gai
n
+
-
Frequency Response Curve (FRC)
Frequencylow high
Gai
n
+
-
Center frequency
lower cutofffrequency
upper cutoff frequency
passband
3 dB
Operation of a filter on a signal
NOTE Amplitude spectrum describes a soundFrequency response curve describes a filter
Learning Objectivesbull Define resonance free and forced vibrationbull Describe how the pendulum and spring mass models can
help explain resonancebull Outline how mass and stiffness influences the resonant
frequency of a mass spring systembull Outline how acoustic resonators behave like acoustic filtersbull Calculate resonant frequencies of a uniform tube based on
its physical dimensionsbull Describe how the wavelength of the sound determines the
resonant frequency of tube
Free vibration
bull objects tend to vibrate at a characteristic or resonant frequency (RF)
Forced vibration
bull A vibrating system can force a nearby system into vibration
bull The efficiency with which this is accomplished is related to the similarity in the resonant frequency (RF) of the two systems
Forced vibration
bull If the RF of the two systems are the same the amplitude of forced vibration will be large
bull If the RF of the two systems are quite different the amplitude of forced vibration will be small or nonexistent
Resonance refers to
bull The tendency for an object to vibrate at a particular frequency or frequencies
bull The ability of a vibrating system to force another system into vibration
Back to the mass spring model
bull Vibratory frequency of the mass spring determined byndash Massndash Stiffness of the spring
httpphetcoloradoeduensimulationmass-spring-lab
Acoustic Resonance
bull Ideas from mechanical resonance also applies to acoustic systems
bull Acoustic chambers will transmit sound frequencies with more or less efficiency depending upon the physical characteristics
bull Therefore they act as filters passing through (and even amplifying) some frequencies and attentuating others
Acoustic Resonance
bull And since they act as filters they have most of the same features of a filter even though we might use different names
bull Center frequency is often termed the resonant frequency
bull Frequency response curve often termed the resonance curve
Helmholtz Resonator
Actions of a Helmholtz Resonator
Stephen M Tasko
Other Acoustic Resonators Tube Resonators
bull Uniform tubes Factors that influence resonancendash Lengthndash Cross-sectional area along its lengthndash Whether it is closed at either or both ends
Uniform tube closed at one end
Uniform tube closed at one end
Stephen M Tasko
Uniform tube closed at one end
First resonance or formant
F1 = c4lWhere
c=speed of sound (35000 cmsec)l = length of the tube
males ~ 175 cmfemales ~ 14 cm
Higher resonantformant frequencies are odd multiples of F1
For examplebull F1 = (c4l )1
bull F2 = (c4l )3
bull F3 = (c4l )5
Comparing Helmholtz and tube resonators
Resonator Features
Sharply tuned Broadly tuned
Resonator Features
An example of the resonance characteristics of the human vocal tract
Frequency
Gain
SPPA 4030 Speech Science
Topic 1 The Speech Chain
The Speech Chain (Denes amp Pinson 1993)
What information is embedded in the speech signal
Branches of science employed to understand speech communication
Physical Quantities Review An Independent Learning Activity
Assignment 1
Topic 2 The Source-Filter Theory of Speech Production An Intr
Producing Speech
Source-Filter Theory of Speech Production
Vocal tract is a tube that can vary its shape
Source Filter Theory
Same Source Different Filter
Different Source Same Filters
Different Source Same Filters (Human)
Different Source Same Filters (Human) (2)
Different Source Same Filters (Human) (3)
Different Source Same Filters (Human) (4)
Different Source Same Filters (Non-Human)
Different Source Same Filters (Non-Human) (2)
Different Source Same Filters (Non-Human) If it quacks like a
Source Filter Theory Applied Alaryngeal Speech
Source-Filter Theory Applied Esophageal Insufflation Test
Source-Filter Theory Applied Tracheoesophageal (TE) Speech
Source Filter Theory Applied The Talkbox
Source-Filter Theory Applied The Talkbox
Topic 3 A Brief Review of Physical Acoustics
Spring Mass Model
What is sound
Sound-conducting media
Model of air molecule vibration (Time 1)
Model of air molecule vibration (Time 2)
Model of air molecule vibration (Time 3)
Model of air molecule vibration (Time 4)
Model of air molecule vibration (Time 5)
Model of air molecule vibration
Wave action of molecular motion
Amplitude waveform
Amplitude waveform (2)
Where is pressure in this model
Pressure waveform
Measuring Sound
Measuring Sound Signal Amplitude
Measuring Sound Signal Amplitude (2)
What units do we use to measure signal amplitude
Brief Review The decibel scale
Absolute vs relative measurement
Typical reference values
Howeverhellip
Linear vs logarithmic
Linear vs logarithmic (2)
Logarithmic Scale
Logarithmic Scale (2)
Combining the idea of logarithmic and relativehellip
Intensity vs Pressure
Extending the formula to pressure
Measuring Sound Frequencyperiod
Measuring Sound Frequencyperiod (2)
Phase Uniform Circular Motion
Initiating a sound waves that differ only in phase
Spatial variation in pressure wave
Spatial variation in pressure wave
Spatial variation in pressure wave (2)
Relation between frequency and wavelength
Learning Objectives
Graphic representation of sound
Same sound different graphs
Classification of sounds
Simple periodic sound
Simple periodic sound Graphic appearance
Complex periodic sounds
Complex periodic sounds Graphic appearance
Complex periodic sounds Graphic appearance (2)
Glottal Source
Amplitude vs Phase Spectrum
Amplitude vs Phase Spectrum (2)
(Complex) Aperiodic sounds
Aperiodic sounds Graphic appearance
Aperiodic sounds Graphic appearance (2)
Analysis of complex waves
Learning Objectives (2)
The ldquoenveloperdquo of a sound wave
Waveform envelope
Waveform envelope (2)
Spectrum envelope
Thought Question
Amplitude Spectrum Window Size
ldquoInstantaneousrdquo Amplitude Spectra
(Long Term) Average Amplitude Spectrum
Slide 90
Learning Objectives (3)
The Spectrogram
Building a spectrogram
Building a spectrogram
Building a spectrogram (2)
Two main types of spectrograms
Wide vs Narrow Band Spectrograms
Learning Objectives (4)
What is an ldquoAcousticrdquo Filter
Why might we be interested in filters
Kinds of frequency selective filters
Low Pass Filters
High Pass Filters
Band Pass Filter
Frequency Response Curve (FRC)
Operation of a filter on a signal
Learning Objectives (5)
Free vibration
Forced vibration
Forced vibration (2)
Resonance refers to
Back to the mass spring model
Acoustic Resonance
Acoustic Resonance (2)
Helmholtz Resonator
Actions of a Helmholtz Resonator
Other Acoustic Resonators Tube Resonators
Uniform tube closed at one end
Uniform tube closed at one end (2)
Uniform tube closed at one end
Comparing Helmholtz and tube resonators
Slide 122
Slide 123
The Speech Chain (Denes amp Pinson 1993)
What information is embedded in the speech signal
bull Phonetic informationbull Affective informationbull Personal informationbull Transmittal informationbull Diagnostic Information
Branches of science employed to understand speech communication
bull Complex gt one frequency componentbull Aperiodic Does not repeat itselfbull Frequency components are not systematically
relatedbull May be ndash Continuousndash Transient
Aperiodic sounds Graphic appearance
bull Time domainndash no repeating pattern of pressure change
bull Frequency domainndash the spectrum is dense ndash No ldquopicket fencerdquo
bull Auditory impression sounds lsquonoisyrsquo
Aperiodic sounds Graphic appearance
From Hillenbrand
>
Analysis of complex wavesbull Waves can be summedbull Complex waves are the sum of simple wavesbull Fourier French Mathematician
ndash Any complex waveform may be formed by summing sinusoids of various frequency amplitude and phase
bull Fourier Analysisndash Provides a unique (only one) solution for a given sound signalndash Is reflected in the amplitude and phase spectrum of the signalndash Reveals the building blocks of complex waves which are sinusoids
Learning Objectives
bull Draw and differentiate the waveform and the waveform envelope
bull Draw and differentiate the amplitude spectrum the phase spectrum and the spectrum envelope
bull Differential between short-term spectra and long-term average spectra
The ldquoenveloperdquo of a sound wave
bull Waveform envelopendash imaginary smooth line that follows the peak of the
amplitude of a sound pressure waveformbull Spectrum envelopendash Imaginary smooth line drawn on top of the
amplitude spectrum
Waveform envelope
From Hillenbrand
Waveform envelope
Time
>
Spectrum envelope
Frequency
Ampl
itude
Thought Question
Can an aperiodic and complex periodic sound have identical
spectrum envelopes
Amplitude Spectrum Window Size
bull ldquoshort-termrdquo vs ldquolong-term averagerdquo amplitude spectrum
ldquoInstantaneousrdquo Amplitude Spectra
(Long Term) Average Amplitude Spectrum
Learning Objectivesbull Describe how the amplitude spectrum and the spectrogram are
relatedbull Identify the axis units of the spectrogrambull Provide some advantages of the spectrogram over the
amplitude spectrumbull Distinguish between a wide band and narrow band spectrogram
and outline the different information each providesbull Distinguish between a harmonic and a formant on a
spectrogrambull Be able to draw stylized (highly simplified) spectrograms based
on spectra and spectrum envelopes
The Spectrogram
Rotate90 degrees
F
AF
A
Building a spectrogram
Rotate it so thatThe amplitude isComing out of thepage
F
A This is really narrow because it is a slice in time
F
Time
Building a spectrogram
Dark bands= amplitudePeaks
Time
Freq
uenc
y
Building a spectrogram
Two main types of spectrograms
bull Narrow-band spectrogramsndash Akin to amplitude spectrums ldquolined uprdquondash Frequency resolution is really sharp
bull Wide-band spectrogramsndash Akin to spectrum envelopes ldquolined uprdquondash Frequency resolution not so sharp
Highlights harmonic structure
Highlights spectrum envelope
Wide vs Narrow Band Spectrograms
Learning Objectives
bull Define an acoustic filterbull Draw and label a frequency response curvebull Draw and differentiate different types of acoustic
filtersbull Define terms such as cutoff frequency center
frequency roll off rate gain and bandwidthbull Define and draw a basic filter system and relate that
to the source-filter theory of speech production
What is an ldquoAcousticrdquo Filter
bull holds back (attenuates) certain sounds and lets other sounds through - selective
Why might we be interested in filters
bull Human vocal tract acts like a frequency selective acoustic filter
bull Human auditory system behaves as a frequency selective filter
bull helps us understand how speech is produced and perceived
Kinds of frequency selective filters
Low-pass filtersndash Lets low frequencies ldquopass throughrdquo and attenuates high
frequencies
High-pass filtersndash Lets high frequencies ldquopass throughrdquo and attenuates low
frequencies
Band-pass filtersndash Lets a particular frequency range ldquopass throughrdquo and
attenuates other frequencies
Low Pass Filters
Frequencylow high
Gai
n
+
-
High Pass Filters
Frequencylow high
Gai
n
+
-
Band Pass Filter
Frequencylow high
Gai
n
+
-
Frequency Response Curve (FRC)
Frequencylow high
Gai
n
+
-
Center frequency
lower cutofffrequency
upper cutoff frequency
passband
3 dB
Operation of a filter on a signal
NOTE Amplitude spectrum describes a soundFrequency response curve describes a filter
Learning Objectivesbull Define resonance free and forced vibrationbull Describe how the pendulum and spring mass models can
help explain resonancebull Outline how mass and stiffness influences the resonant
frequency of a mass spring systembull Outline how acoustic resonators behave like acoustic filtersbull Calculate resonant frequencies of a uniform tube based on
its physical dimensionsbull Describe how the wavelength of the sound determines the
resonant frequency of tube
Free vibration
bull objects tend to vibrate at a characteristic or resonant frequency (RF)
Forced vibration
bull A vibrating system can force a nearby system into vibration
bull The efficiency with which this is accomplished is related to the similarity in the resonant frequency (RF) of the two systems
Forced vibration
bull If the RF of the two systems are the same the amplitude of forced vibration will be large
bull If the RF of the two systems are quite different the amplitude of forced vibration will be small or nonexistent
Resonance refers to
bull The tendency for an object to vibrate at a particular frequency or frequencies
bull The ability of a vibrating system to force another system into vibration
Back to the mass spring model
bull Vibratory frequency of the mass spring determined byndash Massndash Stiffness of the spring
httpphetcoloradoeduensimulationmass-spring-lab
Acoustic Resonance
bull Ideas from mechanical resonance also applies to acoustic systems
bull Acoustic chambers will transmit sound frequencies with more or less efficiency depending upon the physical characteristics
bull Therefore they act as filters passing through (and even amplifying) some frequencies and attentuating others
Acoustic Resonance
bull And since they act as filters they have most of the same features of a filter even though we might use different names
bull Center frequency is often termed the resonant frequency
bull Frequency response curve often termed the resonance curve
Helmholtz Resonator
Actions of a Helmholtz Resonator
Stephen M Tasko
Other Acoustic Resonators Tube Resonators
bull Uniform tubes Factors that influence resonancendash Lengthndash Cross-sectional area along its lengthndash Whether it is closed at either or both ends
Uniform tube closed at one end
Uniform tube closed at one end
Stephen M Tasko
Uniform tube closed at one end
First resonance or formant
F1 = c4lWhere
c=speed of sound (35000 cmsec)l = length of the tube
males ~ 175 cmfemales ~ 14 cm
Higher resonantformant frequencies are odd multiples of F1
For examplebull F1 = (c4l )1
bull F2 = (c4l )3
bull F3 = (c4l )5
Comparing Helmholtz and tube resonators
Resonator Features
Sharply tuned Broadly tuned
Resonator Features
An example of the resonance characteristics of the human vocal tract
Frequency
Gain
SPPA 4030 Speech Science
Topic 1 The Speech Chain
The Speech Chain (Denes amp Pinson 1993)
What information is embedded in the speech signal
Branches of science employed to understand speech communication
Physical Quantities Review An Independent Learning Activity
Assignment 1
Topic 2 The Source-Filter Theory of Speech Production An Intr
Producing Speech
Source-Filter Theory of Speech Production
Vocal tract is a tube that can vary its shape
Source Filter Theory
Same Source Different Filter
Different Source Same Filters
Different Source Same Filters (Human)
Different Source Same Filters (Human) (2)
Different Source Same Filters (Human) (3)
Different Source Same Filters (Human) (4)
Different Source Same Filters (Non-Human)
Different Source Same Filters (Non-Human) (2)
Different Source Same Filters (Non-Human) If it quacks like a
Source Filter Theory Applied Alaryngeal Speech
Source-Filter Theory Applied Esophageal Insufflation Test
Source-Filter Theory Applied Tracheoesophageal (TE) Speech
Source Filter Theory Applied The Talkbox
Source-Filter Theory Applied The Talkbox
Topic 3 A Brief Review of Physical Acoustics
Spring Mass Model
What is sound
Sound-conducting media
Model of air molecule vibration (Time 1)
Model of air molecule vibration (Time 2)
Model of air molecule vibration (Time 3)
Model of air molecule vibration (Time 4)
Model of air molecule vibration (Time 5)
Model of air molecule vibration
Wave action of molecular motion
Amplitude waveform
Amplitude waveform (2)
Where is pressure in this model
Pressure waveform
Measuring Sound
Measuring Sound Signal Amplitude
Measuring Sound Signal Amplitude (2)
What units do we use to measure signal amplitude
Brief Review The decibel scale
Absolute vs relative measurement
Typical reference values
Howeverhellip
Linear vs logarithmic
Linear vs logarithmic (2)
Logarithmic Scale
Logarithmic Scale (2)
Combining the idea of logarithmic and relativehellip
Intensity vs Pressure
Extending the formula to pressure
Measuring Sound Frequencyperiod
Measuring Sound Frequencyperiod (2)
Phase Uniform Circular Motion
Initiating a sound waves that differ only in phase
Spatial variation in pressure wave
Spatial variation in pressure wave
Spatial variation in pressure wave (2)
Relation between frequency and wavelength
Learning Objectives
Graphic representation of sound
Same sound different graphs
Classification of sounds
Simple periodic sound
Simple periodic sound Graphic appearance
Complex periodic sounds
Complex periodic sounds Graphic appearance
Complex periodic sounds Graphic appearance (2)
Glottal Source
Amplitude vs Phase Spectrum
Amplitude vs Phase Spectrum (2)
(Complex) Aperiodic sounds
Aperiodic sounds Graphic appearance
Aperiodic sounds Graphic appearance (2)
Analysis of complex waves
Learning Objectives (2)
The ldquoenveloperdquo of a sound wave
Waveform envelope
Waveform envelope (2)
Spectrum envelope
Thought Question
Amplitude Spectrum Window Size
ldquoInstantaneousrdquo Amplitude Spectra
(Long Term) Average Amplitude Spectrum
Slide 90
Learning Objectives (3)
The Spectrogram
Building a spectrogram
Building a spectrogram
Building a spectrogram (2)
Two main types of spectrograms
Wide vs Narrow Band Spectrograms
Learning Objectives (4)
What is an ldquoAcousticrdquo Filter
Why might we be interested in filters
Kinds of frequency selective filters
Low Pass Filters
High Pass Filters
Band Pass Filter
Frequency Response Curve (FRC)
Operation of a filter on a signal
Learning Objectives (5)
Free vibration
Forced vibration
Forced vibration (2)
Resonance refers to
Back to the mass spring model
Acoustic Resonance
Acoustic Resonance (2)
Helmholtz Resonator
Actions of a Helmholtz Resonator
Other Acoustic Resonators Tube Resonators
Uniform tube closed at one end
Uniform tube closed at one end (2)
Uniform tube closed at one end
Comparing Helmholtz and tube resonators
Slide 122
Slide 123
What information is embedded in the speech signal
bull Phonetic informationbull Affective informationbull Personal informationbull Transmittal informationbull Diagnostic Information
Branches of science employed to understand speech communication
bull Complex gt one frequency componentbull Aperiodic Does not repeat itselfbull Frequency components are not systematically
relatedbull May be ndash Continuousndash Transient
Aperiodic sounds Graphic appearance
bull Time domainndash no repeating pattern of pressure change
bull Frequency domainndash the spectrum is dense ndash No ldquopicket fencerdquo
bull Auditory impression sounds lsquonoisyrsquo
Aperiodic sounds Graphic appearance
From Hillenbrand
>
Analysis of complex wavesbull Waves can be summedbull Complex waves are the sum of simple wavesbull Fourier French Mathematician
ndash Any complex waveform may be formed by summing sinusoids of various frequency amplitude and phase
bull Fourier Analysisndash Provides a unique (only one) solution for a given sound signalndash Is reflected in the amplitude and phase spectrum of the signalndash Reveals the building blocks of complex waves which are sinusoids
Learning Objectives
bull Draw and differentiate the waveform and the waveform envelope
bull Draw and differentiate the amplitude spectrum the phase spectrum and the spectrum envelope
bull Differential between short-term spectra and long-term average spectra
The ldquoenveloperdquo of a sound wave
bull Waveform envelopendash imaginary smooth line that follows the peak of the
amplitude of a sound pressure waveformbull Spectrum envelopendash Imaginary smooth line drawn on top of the
amplitude spectrum
Waveform envelope
From Hillenbrand
Waveform envelope
Time
>
Spectrum envelope
Frequency
Ampl
itude
Thought Question
Can an aperiodic and complex periodic sound have identical
spectrum envelopes
Amplitude Spectrum Window Size
bull ldquoshort-termrdquo vs ldquolong-term averagerdquo amplitude spectrum
ldquoInstantaneousrdquo Amplitude Spectra
(Long Term) Average Amplitude Spectrum
Learning Objectivesbull Describe how the amplitude spectrum and the spectrogram are
relatedbull Identify the axis units of the spectrogrambull Provide some advantages of the spectrogram over the
amplitude spectrumbull Distinguish between a wide band and narrow band spectrogram
and outline the different information each providesbull Distinguish between a harmonic and a formant on a
spectrogrambull Be able to draw stylized (highly simplified) spectrograms based
on spectra and spectrum envelopes
The Spectrogram
Rotate90 degrees
F
AF
A
Building a spectrogram
Rotate it so thatThe amplitude isComing out of thepage
F
A This is really narrow because it is a slice in time
F
Time
Building a spectrogram
Dark bands= amplitudePeaks
Time
Freq
uenc
y
Building a spectrogram
Two main types of spectrograms
bull Narrow-band spectrogramsndash Akin to amplitude spectrums ldquolined uprdquondash Frequency resolution is really sharp
bull Wide-band spectrogramsndash Akin to spectrum envelopes ldquolined uprdquondash Frequency resolution not so sharp
Highlights harmonic structure
Highlights spectrum envelope
Wide vs Narrow Band Spectrograms
Learning Objectives
bull Define an acoustic filterbull Draw and label a frequency response curvebull Draw and differentiate different types of acoustic
filtersbull Define terms such as cutoff frequency center
frequency roll off rate gain and bandwidthbull Define and draw a basic filter system and relate that
to the source-filter theory of speech production
What is an ldquoAcousticrdquo Filter
bull holds back (attenuates) certain sounds and lets other sounds through - selective
Why might we be interested in filters
bull Human vocal tract acts like a frequency selective acoustic filter
bull Human auditory system behaves as a frequency selective filter
bull helps us understand how speech is produced and perceived
Kinds of frequency selective filters
Low-pass filtersndash Lets low frequencies ldquopass throughrdquo and attenuates high
frequencies
High-pass filtersndash Lets high frequencies ldquopass throughrdquo and attenuates low
frequencies
Band-pass filtersndash Lets a particular frequency range ldquopass throughrdquo and
attenuates other frequencies
Low Pass Filters
Frequencylow high
Gai
n
+
-
High Pass Filters
Frequencylow high
Gai
n
+
-
Band Pass Filter
Frequencylow high
Gai
n
+
-
Frequency Response Curve (FRC)
Frequencylow high
Gai
n
+
-
Center frequency
lower cutofffrequency
upper cutoff frequency
passband
3 dB
Operation of a filter on a signal
NOTE Amplitude spectrum describes a soundFrequency response curve describes a filter
Learning Objectivesbull Define resonance free and forced vibrationbull Describe how the pendulum and spring mass models can
help explain resonancebull Outline how mass and stiffness influences the resonant
frequency of a mass spring systembull Outline how acoustic resonators behave like acoustic filtersbull Calculate resonant frequencies of a uniform tube based on
its physical dimensionsbull Describe how the wavelength of the sound determines the
resonant frequency of tube
Free vibration
bull objects tend to vibrate at a characteristic or resonant frequency (RF)
Forced vibration
bull A vibrating system can force a nearby system into vibration
bull The efficiency with which this is accomplished is related to the similarity in the resonant frequency (RF) of the two systems
Forced vibration
bull If the RF of the two systems are the same the amplitude of forced vibration will be large
bull If the RF of the two systems are quite different the amplitude of forced vibration will be small or nonexistent
Resonance refers to
bull The tendency for an object to vibrate at a particular frequency or frequencies
bull The ability of a vibrating system to force another system into vibration
Back to the mass spring model
bull Vibratory frequency of the mass spring determined byndash Massndash Stiffness of the spring
httpphetcoloradoeduensimulationmass-spring-lab
Acoustic Resonance
bull Ideas from mechanical resonance also applies to acoustic systems
bull Acoustic chambers will transmit sound frequencies with more or less efficiency depending upon the physical characteristics
bull Therefore they act as filters passing through (and even amplifying) some frequencies and attentuating others
Acoustic Resonance
bull And since they act as filters they have most of the same features of a filter even though we might use different names
bull Center frequency is often termed the resonant frequency
bull Frequency response curve often termed the resonance curve
Helmholtz Resonator
Actions of a Helmholtz Resonator
Stephen M Tasko
Other Acoustic Resonators Tube Resonators
bull Uniform tubes Factors that influence resonancendash Lengthndash Cross-sectional area along its lengthndash Whether it is closed at either or both ends
Uniform tube closed at one end
Uniform tube closed at one end
Stephen M Tasko
Uniform tube closed at one end
First resonance or formant
F1 = c4lWhere
c=speed of sound (35000 cmsec)l = length of the tube
males ~ 175 cmfemales ~ 14 cm
Higher resonantformant frequencies are odd multiples of F1
For examplebull F1 = (c4l )1
bull F2 = (c4l )3
bull F3 = (c4l )5
Comparing Helmholtz and tube resonators
Resonator Features
Sharply tuned Broadly tuned
Resonator Features
An example of the resonance characteristics of the human vocal tract
Frequency
Gain
SPPA 4030 Speech Science
Topic 1 The Speech Chain
The Speech Chain (Denes amp Pinson 1993)
What information is embedded in the speech signal
Branches of science employed to understand speech communication
Physical Quantities Review An Independent Learning Activity
Assignment 1
Topic 2 The Source-Filter Theory of Speech Production An Intr
Producing Speech
Source-Filter Theory of Speech Production
Vocal tract is a tube that can vary its shape
Source Filter Theory
Same Source Different Filter
Different Source Same Filters
Different Source Same Filters (Human)
Different Source Same Filters (Human) (2)
Different Source Same Filters (Human) (3)
Different Source Same Filters (Human) (4)
Different Source Same Filters (Non-Human)
Different Source Same Filters (Non-Human) (2)
Different Source Same Filters (Non-Human) If it quacks like a
Source Filter Theory Applied Alaryngeal Speech
Source-Filter Theory Applied Esophageal Insufflation Test
Source-Filter Theory Applied Tracheoesophageal (TE) Speech
Source Filter Theory Applied The Talkbox
Source-Filter Theory Applied The Talkbox
Topic 3 A Brief Review of Physical Acoustics
Spring Mass Model
What is sound
Sound-conducting media
Model of air molecule vibration (Time 1)
Model of air molecule vibration (Time 2)
Model of air molecule vibration (Time 3)
Model of air molecule vibration (Time 4)
Model of air molecule vibration (Time 5)
Model of air molecule vibration
Wave action of molecular motion
Amplitude waveform
Amplitude waveform (2)
Where is pressure in this model
Pressure waveform
Measuring Sound
Measuring Sound Signal Amplitude
Measuring Sound Signal Amplitude (2)
What units do we use to measure signal amplitude
Brief Review The decibel scale
Absolute vs relative measurement
Typical reference values
Howeverhellip
Linear vs logarithmic
Linear vs logarithmic (2)
Logarithmic Scale
Logarithmic Scale (2)
Combining the idea of logarithmic and relativehellip
Intensity vs Pressure
Extending the formula to pressure
Measuring Sound Frequencyperiod
Measuring Sound Frequencyperiod (2)
Phase Uniform Circular Motion
Initiating a sound waves that differ only in phase
Spatial variation in pressure wave
Spatial variation in pressure wave
Spatial variation in pressure wave (2)
Relation between frequency and wavelength
Learning Objectives
Graphic representation of sound
Same sound different graphs
Classification of sounds
Simple periodic sound
Simple periodic sound Graphic appearance
Complex periodic sounds
Complex periodic sounds Graphic appearance
Complex periodic sounds Graphic appearance (2)
Glottal Source
Amplitude vs Phase Spectrum
Amplitude vs Phase Spectrum (2)
(Complex) Aperiodic sounds
Aperiodic sounds Graphic appearance
Aperiodic sounds Graphic appearance (2)
Analysis of complex waves
Learning Objectives (2)
The ldquoenveloperdquo of a sound wave
Waveform envelope
Waveform envelope (2)
Spectrum envelope
Thought Question
Amplitude Spectrum Window Size
ldquoInstantaneousrdquo Amplitude Spectra
(Long Term) Average Amplitude Spectrum
Slide 90
Learning Objectives (3)
The Spectrogram
Building a spectrogram
Building a spectrogram
Building a spectrogram (2)
Two main types of spectrograms
Wide vs Narrow Band Spectrograms
Learning Objectives (4)
What is an ldquoAcousticrdquo Filter
Why might we be interested in filters
Kinds of frequency selective filters
Low Pass Filters
High Pass Filters
Band Pass Filter
Frequency Response Curve (FRC)
Operation of a filter on a signal
Learning Objectives (5)
Free vibration
Forced vibration
Forced vibration (2)
Resonance refers to
Back to the mass spring model
Acoustic Resonance
Acoustic Resonance (2)
Helmholtz Resonator
Actions of a Helmholtz Resonator
Other Acoustic Resonators Tube Resonators
Uniform tube closed at one end
Uniform tube closed at one end (2)
Uniform tube closed at one end
Comparing Helmholtz and tube resonators
Slide 122
Slide 123
Branches of science employed to understand speech communication
bull Complex gt one frequency componentbull Aperiodic Does not repeat itselfbull Frequency components are not systematically
relatedbull May be ndash Continuousndash Transient
Aperiodic sounds Graphic appearance
bull Time domainndash no repeating pattern of pressure change
bull Frequency domainndash the spectrum is dense ndash No ldquopicket fencerdquo
bull Auditory impression sounds lsquonoisyrsquo
Aperiodic sounds Graphic appearance
From Hillenbrand
>
Analysis of complex wavesbull Waves can be summedbull Complex waves are the sum of simple wavesbull Fourier French Mathematician
ndash Any complex waveform may be formed by summing sinusoids of various frequency amplitude and phase
bull Fourier Analysisndash Provides a unique (only one) solution for a given sound signalndash Is reflected in the amplitude and phase spectrum of the signalndash Reveals the building blocks of complex waves which are sinusoids
Learning Objectives
bull Draw and differentiate the waveform and the waveform envelope
bull Draw and differentiate the amplitude spectrum the phase spectrum and the spectrum envelope
bull Differential between short-term spectra and long-term average spectra
The ldquoenveloperdquo of a sound wave
bull Waveform envelopendash imaginary smooth line that follows the peak of the
amplitude of a sound pressure waveformbull Spectrum envelopendash Imaginary smooth line drawn on top of the
amplitude spectrum
Waveform envelope
From Hillenbrand
Waveform envelope
Time
>
Spectrum envelope
Frequency
Ampl
itude
Thought Question
Can an aperiodic and complex periodic sound have identical
spectrum envelopes
Amplitude Spectrum Window Size
bull ldquoshort-termrdquo vs ldquolong-term averagerdquo amplitude spectrum
ldquoInstantaneousrdquo Amplitude Spectra
(Long Term) Average Amplitude Spectrum
Learning Objectivesbull Describe how the amplitude spectrum and the spectrogram are
relatedbull Identify the axis units of the spectrogrambull Provide some advantages of the spectrogram over the
amplitude spectrumbull Distinguish between a wide band and narrow band spectrogram
and outline the different information each providesbull Distinguish between a harmonic and a formant on a
spectrogrambull Be able to draw stylized (highly simplified) spectrograms based
on spectra and spectrum envelopes
The Spectrogram
Rotate90 degrees
F
AF
A
Building a spectrogram
Rotate it so thatThe amplitude isComing out of thepage
F
A This is really narrow because it is a slice in time
F
Time
Building a spectrogram
Dark bands= amplitudePeaks
Time
Freq
uenc
y
Building a spectrogram
Two main types of spectrograms
bull Narrow-band spectrogramsndash Akin to amplitude spectrums ldquolined uprdquondash Frequency resolution is really sharp
bull Wide-band spectrogramsndash Akin to spectrum envelopes ldquolined uprdquondash Frequency resolution not so sharp
Highlights harmonic structure
Highlights spectrum envelope
Wide vs Narrow Band Spectrograms
Learning Objectives
bull Define an acoustic filterbull Draw and label a frequency response curvebull Draw and differentiate different types of acoustic
filtersbull Define terms such as cutoff frequency center
frequency roll off rate gain and bandwidthbull Define and draw a basic filter system and relate that
to the source-filter theory of speech production
What is an ldquoAcousticrdquo Filter
bull holds back (attenuates) certain sounds and lets other sounds through - selective
Why might we be interested in filters
bull Human vocal tract acts like a frequency selective acoustic filter
bull Human auditory system behaves as a frequency selective filter
bull helps us understand how speech is produced and perceived
Kinds of frequency selective filters
Low-pass filtersndash Lets low frequencies ldquopass throughrdquo and attenuates high
frequencies
High-pass filtersndash Lets high frequencies ldquopass throughrdquo and attenuates low
frequencies
Band-pass filtersndash Lets a particular frequency range ldquopass throughrdquo and
attenuates other frequencies
Low Pass Filters
Frequencylow high
Gai
n
+
-
High Pass Filters
Frequencylow high
Gai
n
+
-
Band Pass Filter
Frequencylow high
Gai
n
+
-
Frequency Response Curve (FRC)
Frequencylow high
Gai
n
+
-
Center frequency
lower cutofffrequency
upper cutoff frequency
passband
3 dB
Operation of a filter on a signal
NOTE Amplitude spectrum describes a soundFrequency response curve describes a filter
Learning Objectivesbull Define resonance free and forced vibrationbull Describe how the pendulum and spring mass models can
help explain resonancebull Outline how mass and stiffness influences the resonant
frequency of a mass spring systembull Outline how acoustic resonators behave like acoustic filtersbull Calculate resonant frequencies of a uniform tube based on
its physical dimensionsbull Describe how the wavelength of the sound determines the
resonant frequency of tube
Free vibration
bull objects tend to vibrate at a characteristic or resonant frequency (RF)
Forced vibration
bull A vibrating system can force a nearby system into vibration
bull The efficiency with which this is accomplished is related to the similarity in the resonant frequency (RF) of the two systems
Forced vibration
bull If the RF of the two systems are the same the amplitude of forced vibration will be large
bull If the RF of the two systems are quite different the amplitude of forced vibration will be small or nonexistent
Resonance refers to
bull The tendency for an object to vibrate at a particular frequency or frequencies
bull The ability of a vibrating system to force another system into vibration
Back to the mass spring model
bull Vibratory frequency of the mass spring determined byndash Massndash Stiffness of the spring
httpphetcoloradoeduensimulationmass-spring-lab
Acoustic Resonance
bull Ideas from mechanical resonance also applies to acoustic systems
bull Acoustic chambers will transmit sound frequencies with more or less efficiency depending upon the physical characteristics
bull Therefore they act as filters passing through (and even amplifying) some frequencies and attentuating others
Acoustic Resonance
bull And since they act as filters they have most of the same features of a filter even though we might use different names
bull Center frequency is often termed the resonant frequency
bull Frequency response curve often termed the resonance curve
Helmholtz Resonator
Actions of a Helmholtz Resonator
Stephen M Tasko
Other Acoustic Resonators Tube Resonators
bull Uniform tubes Factors that influence resonancendash Lengthndash Cross-sectional area along its lengthndash Whether it is closed at either or both ends
Uniform tube closed at one end
Uniform tube closed at one end
Stephen M Tasko
Uniform tube closed at one end
First resonance or formant
F1 = c4lWhere
c=speed of sound (35000 cmsec)l = length of the tube
males ~ 175 cmfemales ~ 14 cm
Higher resonantformant frequencies are odd multiples of F1
For examplebull F1 = (c4l )1
bull F2 = (c4l )3
bull F3 = (c4l )5
Comparing Helmholtz and tube resonators
Resonator Features
Sharply tuned Broadly tuned
Resonator Features
An example of the resonance characteristics of the human vocal tract
Frequency
Gain
SPPA 4030 Speech Science
Topic 1 The Speech Chain
The Speech Chain (Denes amp Pinson 1993)
What information is embedded in the speech signal
Branches of science employed to understand speech communication
Physical Quantities Review An Independent Learning Activity
Assignment 1
Topic 2 The Source-Filter Theory of Speech Production An Intr
Producing Speech
Source-Filter Theory of Speech Production
Vocal tract is a tube that can vary its shape
Source Filter Theory
Same Source Different Filter
Different Source Same Filters
Different Source Same Filters (Human)
Different Source Same Filters (Human) (2)
Different Source Same Filters (Human) (3)
Different Source Same Filters (Human) (4)
Different Source Same Filters (Non-Human)
Different Source Same Filters (Non-Human) (2)
Different Source Same Filters (Non-Human) If it quacks like a
Source Filter Theory Applied Alaryngeal Speech
Source-Filter Theory Applied Esophageal Insufflation Test
Source-Filter Theory Applied Tracheoesophageal (TE) Speech
Source Filter Theory Applied The Talkbox
Source-Filter Theory Applied The Talkbox
Topic 3 A Brief Review of Physical Acoustics
Spring Mass Model
What is sound
Sound-conducting media
Model of air molecule vibration (Time 1)
Model of air molecule vibration (Time 2)
Model of air molecule vibration (Time 3)
Model of air molecule vibration (Time 4)
Model of air molecule vibration (Time 5)
Model of air molecule vibration
Wave action of molecular motion
Amplitude waveform
Amplitude waveform (2)
Where is pressure in this model
Pressure waveform
Measuring Sound
Measuring Sound Signal Amplitude
Measuring Sound Signal Amplitude (2)
What units do we use to measure signal amplitude
Brief Review The decibel scale
Absolute vs relative measurement
Typical reference values
Howeverhellip
Linear vs logarithmic
Linear vs logarithmic (2)
Logarithmic Scale
Logarithmic Scale (2)
Combining the idea of logarithmic and relativehellip
Intensity vs Pressure
Extending the formula to pressure
Measuring Sound Frequencyperiod
Measuring Sound Frequencyperiod (2)
Phase Uniform Circular Motion
Initiating a sound waves that differ only in phase
bull Complex gt one frequency componentbull Aperiodic Does not repeat itselfbull Frequency components are not systematically
relatedbull May be ndash Continuousndash Transient
Aperiodic sounds Graphic appearance
bull Time domainndash no repeating pattern of pressure change
bull Frequency domainndash the spectrum is dense ndash No ldquopicket fencerdquo
bull Auditory impression sounds lsquonoisyrsquo
Aperiodic sounds Graphic appearance
From Hillenbrand
>
Analysis of complex wavesbull Waves can be summedbull Complex waves are the sum of simple wavesbull Fourier French Mathematician
ndash Any complex waveform may be formed by summing sinusoids of various frequency amplitude and phase
bull Fourier Analysisndash Provides a unique (only one) solution for a given sound signalndash Is reflected in the amplitude and phase spectrum of the signalndash Reveals the building blocks of complex waves which are sinusoids
Learning Objectives
bull Draw and differentiate the waveform and the waveform envelope
bull Draw and differentiate the amplitude spectrum the phase spectrum and the spectrum envelope
bull Differential between short-term spectra and long-term average spectra
The ldquoenveloperdquo of a sound wave
bull Waveform envelopendash imaginary smooth line that follows the peak of the
amplitude of a sound pressure waveformbull Spectrum envelopendash Imaginary smooth line drawn on top of the
amplitude spectrum
Waveform envelope
From Hillenbrand
Waveform envelope
Time
>
Spectrum envelope
Frequency
Ampl
itude
Thought Question
Can an aperiodic and complex periodic sound have identical
spectrum envelopes
Amplitude Spectrum Window Size
bull ldquoshort-termrdquo vs ldquolong-term averagerdquo amplitude spectrum
ldquoInstantaneousrdquo Amplitude Spectra
(Long Term) Average Amplitude Spectrum
Learning Objectivesbull Describe how the amplitude spectrum and the spectrogram are
relatedbull Identify the axis units of the spectrogrambull Provide some advantages of the spectrogram over the
amplitude spectrumbull Distinguish between a wide band and narrow band spectrogram
and outline the different information each providesbull Distinguish between a harmonic and a formant on a
spectrogrambull Be able to draw stylized (highly simplified) spectrograms based
on spectra and spectrum envelopes
The Spectrogram
Rotate90 degrees
F
AF
A
Building a spectrogram
Rotate it so thatThe amplitude isComing out of thepage
F
A This is really narrow because it is a slice in time
F
Time
Building a spectrogram
Dark bands= amplitudePeaks
Time
Freq
uenc
y
Building a spectrogram
Two main types of spectrograms
bull Narrow-band spectrogramsndash Akin to amplitude spectrums ldquolined uprdquondash Frequency resolution is really sharp
bull Wide-band spectrogramsndash Akin to spectrum envelopes ldquolined uprdquondash Frequency resolution not so sharp
Highlights harmonic structure
Highlights spectrum envelope
Wide vs Narrow Band Spectrograms
Learning Objectives
bull Define an acoustic filterbull Draw and label a frequency response curvebull Draw and differentiate different types of acoustic
filtersbull Define terms such as cutoff frequency center
frequency roll off rate gain and bandwidthbull Define and draw a basic filter system and relate that
to the source-filter theory of speech production
What is an ldquoAcousticrdquo Filter
bull holds back (attenuates) certain sounds and lets other sounds through - selective
Why might we be interested in filters
bull Human vocal tract acts like a frequency selective acoustic filter
bull Human auditory system behaves as a frequency selective filter
bull helps us understand how speech is produced and perceived
Kinds of frequency selective filters
Low-pass filtersndash Lets low frequencies ldquopass throughrdquo and attenuates high
frequencies
High-pass filtersndash Lets high frequencies ldquopass throughrdquo and attenuates low
frequencies
Band-pass filtersndash Lets a particular frequency range ldquopass throughrdquo and
attenuates other frequencies
Low Pass Filters
Frequencylow high
Gai
n
+
-
High Pass Filters
Frequencylow high
Gai
n
+
-
Band Pass Filter
Frequencylow high
Gai
n
+
-
Frequency Response Curve (FRC)
Frequencylow high
Gai
n
+
-
Center frequency
lower cutofffrequency
upper cutoff frequency
passband
3 dB
Operation of a filter on a signal
NOTE Amplitude spectrum describes a soundFrequency response curve describes a filter
Learning Objectivesbull Define resonance free and forced vibrationbull Describe how the pendulum and spring mass models can
help explain resonancebull Outline how mass and stiffness influences the resonant
frequency of a mass spring systembull Outline how acoustic resonators behave like acoustic filtersbull Calculate resonant frequencies of a uniform tube based on
its physical dimensionsbull Describe how the wavelength of the sound determines the
resonant frequency of tube
Free vibration
bull objects tend to vibrate at a characteristic or resonant frequency (RF)
Forced vibration
bull A vibrating system can force a nearby system into vibration
bull The efficiency with which this is accomplished is related to the similarity in the resonant frequency (RF) of the two systems
Forced vibration
bull If the RF of the two systems are the same the amplitude of forced vibration will be large
bull If the RF of the two systems are quite different the amplitude of forced vibration will be small or nonexistent
Resonance refers to
bull The tendency for an object to vibrate at a particular frequency or frequencies
bull The ability of a vibrating system to force another system into vibration
Back to the mass spring model
bull Vibratory frequency of the mass spring determined byndash Massndash Stiffness of the spring
httpphetcoloradoeduensimulationmass-spring-lab
Acoustic Resonance
bull Ideas from mechanical resonance also applies to acoustic systems
bull Acoustic chambers will transmit sound frequencies with more or less efficiency depending upon the physical characteristics
bull Therefore they act as filters passing through (and even amplifying) some frequencies and attentuating others
Acoustic Resonance
bull And since they act as filters they have most of the same features of a filter even though we might use different names
bull Center frequency is often termed the resonant frequency
bull Frequency response curve often termed the resonance curve
Helmholtz Resonator
Actions of a Helmholtz Resonator
Stephen M Tasko
Other Acoustic Resonators Tube Resonators
bull Uniform tubes Factors that influence resonancendash Lengthndash Cross-sectional area along its lengthndash Whether it is closed at either or both ends
Uniform tube closed at one end
Uniform tube closed at one end
Stephen M Tasko
Uniform tube closed at one end
First resonance or formant
F1 = c4lWhere
c=speed of sound (35000 cmsec)l = length of the tube
males ~ 175 cmfemales ~ 14 cm
Higher resonantformant frequencies are odd multiples of F1
For examplebull F1 = (c4l )1
bull F2 = (c4l )3
bull F3 = (c4l )5
Comparing Helmholtz and tube resonators
Resonator Features
Sharply tuned Broadly tuned
Resonator Features
An example of the resonance characteristics of the human vocal tract
Frequency
Gain
SPPA 4030 Speech Science
Topic 1 The Speech Chain
The Speech Chain (Denes amp Pinson 1993)
What information is embedded in the speech signal
Branches of science employed to understand speech communication
Physical Quantities Review An Independent Learning Activity
Assignment 1
Topic 2 The Source-Filter Theory of Speech Production An Intr
Producing Speech
Source-Filter Theory of Speech Production
Vocal tract is a tube that can vary its shape
Source Filter Theory
Same Source Different Filter
Different Source Same Filters
Different Source Same Filters (Human)
Different Source Same Filters (Human) (2)
Different Source Same Filters (Human) (3)
Different Source Same Filters (Human) (4)
Different Source Same Filters (Non-Human)
Different Source Same Filters (Non-Human) (2)
Different Source Same Filters (Non-Human) If it quacks like a
Source Filter Theory Applied Alaryngeal Speech
Source-Filter Theory Applied Esophageal Insufflation Test
Source-Filter Theory Applied Tracheoesophageal (TE) Speech
Source Filter Theory Applied The Talkbox
Source-Filter Theory Applied The Talkbox
Topic 3 A Brief Review of Physical Acoustics
Spring Mass Model
What is sound
Sound-conducting media
Model of air molecule vibration (Time 1)
Model of air molecule vibration (Time 2)
Model of air molecule vibration (Time 3)
Model of air molecule vibration (Time 4)
Model of air molecule vibration (Time 5)
Model of air molecule vibration
Wave action of molecular motion
Amplitude waveform
Amplitude waveform (2)
Where is pressure in this model
Pressure waveform
Measuring Sound
Measuring Sound Signal Amplitude
Measuring Sound Signal Amplitude (2)
What units do we use to measure signal amplitude
Brief Review The decibel scale
Absolute vs relative measurement
Typical reference values
Howeverhellip
Linear vs logarithmic
Linear vs logarithmic (2)
Logarithmic Scale
Logarithmic Scale (2)
Combining the idea of logarithmic and relativehellip
Intensity vs Pressure
Extending the formula to pressure
Measuring Sound Frequencyperiod
Measuring Sound Frequencyperiod (2)
Phase Uniform Circular Motion
Initiating a sound waves that differ only in phase
Spatial variation in pressure wave
Spatial variation in pressure wave
Spatial variation in pressure wave (2)
Relation between frequency and wavelength
Learning Objectives
Graphic representation of sound
Same sound different graphs
Classification of sounds
Simple periodic sound
Simple periodic sound Graphic appearance
Complex periodic sounds
Complex periodic sounds Graphic appearance
Complex periodic sounds Graphic appearance (2)
Glottal Source
Amplitude vs Phase Spectrum
Amplitude vs Phase Spectrum (2)
(Complex) Aperiodic sounds
Aperiodic sounds Graphic appearance
Aperiodic sounds Graphic appearance (2)
Analysis of complex waves
Learning Objectives (2)
The ldquoenveloperdquo of a sound wave
Waveform envelope
Waveform envelope (2)
Spectrum envelope
Thought Question
Amplitude Spectrum Window Size
ldquoInstantaneousrdquo Amplitude Spectra
(Long Term) Average Amplitude Spectrum
Slide 90
Learning Objectives (3)
The Spectrogram
Building a spectrogram
Building a spectrogram
Building a spectrogram (2)
Two main types of spectrograms
Wide vs Narrow Band Spectrograms
Learning Objectives (4)
What is an ldquoAcousticrdquo Filter
Why might we be interested in filters
Kinds of frequency selective filters
Low Pass Filters
High Pass Filters
Band Pass Filter
Frequency Response Curve (FRC)
Operation of a filter on a signal
Learning Objectives (5)
Free vibration
Forced vibration
Forced vibration (2)
Resonance refers to
Back to the mass spring model
Acoustic Resonance
Acoustic Resonance (2)
Helmholtz Resonator
Actions of a Helmholtz Resonator
Other Acoustic Resonators Tube Resonators
Uniform tube closed at one end
Uniform tube closed at one end (2)
Uniform tube closed at one end
Comparing Helmholtz and tube resonators
Slide 122
Slide 123
Assignment 1
bull See Assignments section of course websitebull Due September 12 2013
Topic 2 The Source-Filter Theory of Speech Production An Introduction
Learning Objectivesbull Outline the key assumptions of the source filter theory
of speech productionbull Distinguish between the source signal filter
characteristics and the output signalbull Use a range of examples to demonstrate
understanding of the source filter theorybull Distinguish to role that different vocal tract structures
play in speech sound generation and speech sound filtering
Producing Speech
bull The vocal tract can be conceived as a set of interconnecting tubes and valves
bull Speech production is achieved through the systematic regulation of air pressures and flows within the vocal tract
Source-Filter Theory of Speech Production
bull The sounds we hear as speech is the product of a sound source that has undergone filtering by the vocal tract
bull source and the filter may be considered to be independent of each other
Vocal tract is a tube that can vary its shape
From Titze (1994)
Source Filter Theory
Source(Phonation)
Filter(Resonator)
Speech(What We Hear)
Input Spectrum Frequency ResponseCurve
Output Spectrum
>
>
Same Source Different Filter
>
>
>
>
Different Source Same Filters
White Noise
>
>
>
>
Different Source Same Filters (Human)
burp
>
>
>
>
Different Source Same Filters (Human)
snore
>
>
>
>
Different Source Same Filters (Human)
Lip buzz
>
>
>
>
Different Source Same Filters (Human)
>
>
>
>
Different Source Same Filters (Non-Human)
sheep
>
>
>
>
Different Source Same Filters (Non-Human)
accordion
>
>
>
>
Different Source Same Filters (Non-Human)If it quacks like a duckhellip
>
>
>
>
Source Filter Theory Applied Alaryngeal Speech
Source-Filter Theory AppliedEsophageal Insufflation Test
Source-Filter Theory AppliedTracheoesophageal (TE) Speech
Source Filter Theory Applied The Talkbox
Source-Filter Theory Applied The Talkbox
httpwwwyoutubecomwatchv=YS3gAVNlceg
Topic 3 A Brief Review of Physical Acoustics
Learning Objectivesbull Outline the physical processes underlying simple harmonic motion using the
mass-spring modelbull Describe the molecular basis of sound wave propagationbull Define the key characteristics of sinusoidal motion including
ndash Amplitude instantaneous peak peak-to-peak root-mean-square (RMS) the decibel scale
ndash Frequencyperiod including units of measurendash Phasendash Wavelength
bull Briefly describe the relation between the sine wave and uniform circular motion
bull Outline the relationship between the frequency and wavelength of a sound wave
Spring Mass Model
bull Mass (inertia)ndash Newtonrsquos first law of motionndash Opposition to
accelerationdecelerationbull Elasticityndash Opposition to displacementndash Rest positionndash Recoil force
bull Complex gt one frequency componentbull Aperiodic Does not repeat itselfbull Frequency components are not systematically
relatedbull May be ndash Continuousndash Transient
Aperiodic sounds Graphic appearance
bull Time domainndash no repeating pattern of pressure change
bull Frequency domainndash the spectrum is dense ndash No ldquopicket fencerdquo
bull Auditory impression sounds lsquonoisyrsquo
Aperiodic sounds Graphic appearance
From Hillenbrand
>
Analysis of complex wavesbull Waves can be summedbull Complex waves are the sum of simple wavesbull Fourier French Mathematician
ndash Any complex waveform may be formed by summing sinusoids of various frequency amplitude and phase
bull Fourier Analysisndash Provides a unique (only one) solution for a given sound signalndash Is reflected in the amplitude and phase spectrum of the signalndash Reveals the building blocks of complex waves which are sinusoids
Learning Objectives
bull Draw and differentiate the waveform and the waveform envelope
bull Draw and differentiate the amplitude spectrum the phase spectrum and the spectrum envelope
bull Differential between short-term spectra and long-term average spectra
The ldquoenveloperdquo of a sound wave
bull Waveform envelopendash imaginary smooth line that follows the peak of the
amplitude of a sound pressure waveformbull Spectrum envelopendash Imaginary smooth line drawn on top of the
amplitude spectrum
Waveform envelope
From Hillenbrand
Waveform envelope
Time
>
Spectrum envelope
Frequency
Ampl
itude
Thought Question
Can an aperiodic and complex periodic sound have identical
spectrum envelopes
Amplitude Spectrum Window Size
bull ldquoshort-termrdquo vs ldquolong-term averagerdquo amplitude spectrum
ldquoInstantaneousrdquo Amplitude Spectra
(Long Term) Average Amplitude Spectrum
Learning Objectivesbull Describe how the amplitude spectrum and the spectrogram are
relatedbull Identify the axis units of the spectrogrambull Provide some advantages of the spectrogram over the
amplitude spectrumbull Distinguish between a wide band and narrow band spectrogram
and outline the different information each providesbull Distinguish between a harmonic and a formant on a
spectrogrambull Be able to draw stylized (highly simplified) spectrograms based
on spectra and spectrum envelopes
The Spectrogram
Rotate90 degrees
F
AF
A
Building a spectrogram
Rotate it so thatThe amplitude isComing out of thepage
F
A This is really narrow because it is a slice in time
F
Time
Building a spectrogram
Dark bands= amplitudePeaks
Time
Freq
uenc
y
Building a spectrogram
Two main types of spectrograms
bull Narrow-band spectrogramsndash Akin to amplitude spectrums ldquolined uprdquondash Frequency resolution is really sharp
bull Wide-band spectrogramsndash Akin to spectrum envelopes ldquolined uprdquondash Frequency resolution not so sharp
Highlights harmonic structure
Highlights spectrum envelope
Wide vs Narrow Band Spectrograms
Learning Objectives
bull Define an acoustic filterbull Draw and label a frequency response curvebull Draw and differentiate different types of acoustic
filtersbull Define terms such as cutoff frequency center
frequency roll off rate gain and bandwidthbull Define and draw a basic filter system and relate that
to the source-filter theory of speech production
What is an ldquoAcousticrdquo Filter
bull holds back (attenuates) certain sounds and lets other sounds through - selective
Why might we be interested in filters
bull Human vocal tract acts like a frequency selective acoustic filter
bull Human auditory system behaves as a frequency selective filter
bull helps us understand how speech is produced and perceived
Kinds of frequency selective filters
Low-pass filtersndash Lets low frequencies ldquopass throughrdquo and attenuates high
frequencies
High-pass filtersndash Lets high frequencies ldquopass throughrdquo and attenuates low
frequencies
Band-pass filtersndash Lets a particular frequency range ldquopass throughrdquo and
attenuates other frequencies
Low Pass Filters
Frequencylow high
Gai
n
+
-
High Pass Filters
Frequencylow high
Gai
n
+
-
Band Pass Filter
Frequencylow high
Gai
n
+
-
Frequency Response Curve (FRC)
Frequencylow high
Gai
n
+
-
Center frequency
lower cutofffrequency
upper cutoff frequency
passband
3 dB
Operation of a filter on a signal
NOTE Amplitude spectrum describes a soundFrequency response curve describes a filter
Learning Objectivesbull Define resonance free and forced vibrationbull Describe how the pendulum and spring mass models can
help explain resonancebull Outline how mass and stiffness influences the resonant
frequency of a mass spring systembull Outline how acoustic resonators behave like acoustic filtersbull Calculate resonant frequencies of a uniform tube based on
its physical dimensionsbull Describe how the wavelength of the sound determines the
resonant frequency of tube
Free vibration
bull objects tend to vibrate at a characteristic or resonant frequency (RF)
Forced vibration
bull A vibrating system can force a nearby system into vibration
bull The efficiency with which this is accomplished is related to the similarity in the resonant frequency (RF) of the two systems
Forced vibration
bull If the RF of the two systems are the same the amplitude of forced vibration will be large
bull If the RF of the two systems are quite different the amplitude of forced vibration will be small or nonexistent
Resonance refers to
bull The tendency for an object to vibrate at a particular frequency or frequencies
bull The ability of a vibrating system to force another system into vibration
Back to the mass spring model
bull Vibratory frequency of the mass spring determined byndash Massndash Stiffness of the spring
httpphetcoloradoeduensimulationmass-spring-lab
Acoustic Resonance
bull Ideas from mechanical resonance also applies to acoustic systems
bull Acoustic chambers will transmit sound frequencies with more or less efficiency depending upon the physical characteristics
bull Therefore they act as filters passing through (and even amplifying) some frequencies and attentuating others
Acoustic Resonance
bull And since they act as filters they have most of the same features of a filter even though we might use different names
bull Center frequency is often termed the resonant frequency
bull Frequency response curve often termed the resonance curve
Helmholtz Resonator
Actions of a Helmholtz Resonator
Stephen M Tasko
Other Acoustic Resonators Tube Resonators
bull Uniform tubes Factors that influence resonancendash Lengthndash Cross-sectional area along its lengthndash Whether it is closed at either or both ends
Uniform tube closed at one end
Uniform tube closed at one end
Stephen M Tasko
Uniform tube closed at one end
First resonance or formant
F1 = c4lWhere
c=speed of sound (35000 cmsec)l = length of the tube
males ~ 175 cmfemales ~ 14 cm
Higher resonantformant frequencies are odd multiples of F1
For examplebull F1 = (c4l )1
bull F2 = (c4l )3
bull F3 = (c4l )5
Comparing Helmholtz and tube resonators
Resonator Features
Sharply tuned Broadly tuned
Resonator Features
An example of the resonance characteristics of the human vocal tract
Frequency
Gain
SPPA 4030 Speech Science
Topic 1 The Speech Chain
The Speech Chain (Denes amp Pinson 1993)
What information is embedded in the speech signal
Branches of science employed to understand speech communication
Physical Quantities Review An Independent Learning Activity
Assignment 1
Topic 2 The Source-Filter Theory of Speech Production An Intr
Producing Speech
Source-Filter Theory of Speech Production
Vocal tract is a tube that can vary its shape
Source Filter Theory
Same Source Different Filter
Different Source Same Filters
Different Source Same Filters (Human)
Different Source Same Filters (Human) (2)
Different Source Same Filters (Human) (3)
Different Source Same Filters (Human) (4)
Different Source Same Filters (Non-Human)
Different Source Same Filters (Non-Human) (2)
Different Source Same Filters (Non-Human) If it quacks like a
Source Filter Theory Applied Alaryngeal Speech
Source-Filter Theory Applied Esophageal Insufflation Test
Source-Filter Theory Applied Tracheoesophageal (TE) Speech
Source Filter Theory Applied The Talkbox
Source-Filter Theory Applied The Talkbox
Topic 3 A Brief Review of Physical Acoustics
Spring Mass Model
What is sound
Sound-conducting media
Model of air molecule vibration (Time 1)
Model of air molecule vibration (Time 2)
Model of air molecule vibration (Time 3)
Model of air molecule vibration (Time 4)
Model of air molecule vibration (Time 5)
Model of air molecule vibration
Wave action of molecular motion
Amplitude waveform
Amplitude waveform (2)
Where is pressure in this model
Pressure waveform
Measuring Sound
Measuring Sound Signal Amplitude
Measuring Sound Signal Amplitude (2)
What units do we use to measure signal amplitude
Brief Review The decibel scale
Absolute vs relative measurement
Typical reference values
Howeverhellip
Linear vs logarithmic
Linear vs logarithmic (2)
Logarithmic Scale
Logarithmic Scale (2)
Combining the idea of logarithmic and relativehellip
Intensity vs Pressure
Extending the formula to pressure
Measuring Sound Frequencyperiod
Measuring Sound Frequencyperiod (2)
Phase Uniform Circular Motion
Initiating a sound waves that differ only in phase
Spatial variation in pressure wave
Spatial variation in pressure wave
Spatial variation in pressure wave (2)
Relation between frequency and wavelength
Learning Objectives
Graphic representation of sound
Same sound different graphs
Classification of sounds
Simple periodic sound
Simple periodic sound Graphic appearance
Complex periodic sounds
Complex periodic sounds Graphic appearance
Complex periodic sounds Graphic appearance (2)
Glottal Source
Amplitude vs Phase Spectrum
Amplitude vs Phase Spectrum (2)
(Complex) Aperiodic sounds
Aperiodic sounds Graphic appearance
Aperiodic sounds Graphic appearance (2)
Analysis of complex waves
Learning Objectives (2)
The ldquoenveloperdquo of a sound wave
Waveform envelope
Waveform envelope (2)
Spectrum envelope
Thought Question
Amplitude Spectrum Window Size
ldquoInstantaneousrdquo Amplitude Spectra
(Long Term) Average Amplitude Spectrum
Slide 90
Learning Objectives (3)
The Spectrogram
Building a spectrogram
Building a spectrogram
Building a spectrogram (2)
Two main types of spectrograms
Wide vs Narrow Band Spectrograms
Learning Objectives (4)
What is an ldquoAcousticrdquo Filter
Why might we be interested in filters
Kinds of frequency selective filters
Low Pass Filters
High Pass Filters
Band Pass Filter
Frequency Response Curve (FRC)
Operation of a filter on a signal
Learning Objectives (5)
Free vibration
Forced vibration
Forced vibration (2)
Resonance refers to
Back to the mass spring model
Acoustic Resonance
Acoustic Resonance (2)
Helmholtz Resonator
Actions of a Helmholtz Resonator
Other Acoustic Resonators Tube Resonators
Uniform tube closed at one end
Uniform tube closed at one end (2)
Uniform tube closed at one end
Comparing Helmholtz and tube resonators
Slide 122
Slide 123
Topic 2 The Source-Filter Theory of Speech Production An Introduction
Learning Objectivesbull Outline the key assumptions of the source filter theory
of speech productionbull Distinguish between the source signal filter
characteristics and the output signalbull Use a range of examples to demonstrate
understanding of the source filter theorybull Distinguish to role that different vocal tract structures
play in speech sound generation and speech sound filtering
Producing Speech
bull The vocal tract can be conceived as a set of interconnecting tubes and valves
bull Speech production is achieved through the systematic regulation of air pressures and flows within the vocal tract
Source-Filter Theory of Speech Production
bull The sounds we hear as speech is the product of a sound source that has undergone filtering by the vocal tract
bull source and the filter may be considered to be independent of each other
Vocal tract is a tube that can vary its shape
From Titze (1994)
Source Filter Theory
Source(Phonation)
Filter(Resonator)
Speech(What We Hear)
Input Spectrum Frequency ResponseCurve
Output Spectrum
>
>
Same Source Different Filter
>
>
>
>
Different Source Same Filters
White Noise
>
>
>
>
Different Source Same Filters (Human)
burp
>
>
>
>
Different Source Same Filters (Human)
snore
>
>
>
>
Different Source Same Filters (Human)
Lip buzz
>
>
>
>
Different Source Same Filters (Human)
>
>
>
>
Different Source Same Filters (Non-Human)
sheep
>
>
>
>
Different Source Same Filters (Non-Human)
accordion
>
>
>
>
Different Source Same Filters (Non-Human)If it quacks like a duckhellip
>
>
>
>
Source Filter Theory Applied Alaryngeal Speech
Source-Filter Theory AppliedEsophageal Insufflation Test
Source-Filter Theory AppliedTracheoesophageal (TE) Speech
Source Filter Theory Applied The Talkbox
Source-Filter Theory Applied The Talkbox
httpwwwyoutubecomwatchv=YS3gAVNlceg
Topic 3 A Brief Review of Physical Acoustics
Learning Objectivesbull Outline the physical processes underlying simple harmonic motion using the
mass-spring modelbull Describe the molecular basis of sound wave propagationbull Define the key characteristics of sinusoidal motion including
ndash Amplitude instantaneous peak peak-to-peak root-mean-square (RMS) the decibel scale
ndash Frequencyperiod including units of measurendash Phasendash Wavelength
bull Briefly describe the relation between the sine wave and uniform circular motion
bull Outline the relationship between the frequency and wavelength of a sound wave
Spring Mass Model
bull Mass (inertia)ndash Newtonrsquos first law of motionndash Opposition to
accelerationdecelerationbull Elasticityndash Opposition to displacementndash Rest positionndash Recoil force
bull Complex gt one frequency componentbull Aperiodic Does not repeat itselfbull Frequency components are not systematically
relatedbull May be ndash Continuousndash Transient
Aperiodic sounds Graphic appearance
bull Time domainndash no repeating pattern of pressure change
bull Frequency domainndash the spectrum is dense ndash No ldquopicket fencerdquo
bull Auditory impression sounds lsquonoisyrsquo
Aperiodic sounds Graphic appearance
From Hillenbrand
>
Analysis of complex wavesbull Waves can be summedbull Complex waves are the sum of simple wavesbull Fourier French Mathematician
ndash Any complex waveform may be formed by summing sinusoids of various frequency amplitude and phase
bull Fourier Analysisndash Provides a unique (only one) solution for a given sound signalndash Is reflected in the amplitude and phase spectrum of the signalndash Reveals the building blocks of complex waves which are sinusoids
Learning Objectives
bull Draw and differentiate the waveform and the waveform envelope
bull Draw and differentiate the amplitude spectrum the phase spectrum and the spectrum envelope
bull Differential between short-term spectra and long-term average spectra
The ldquoenveloperdquo of a sound wave
bull Waveform envelopendash imaginary smooth line that follows the peak of the
amplitude of a sound pressure waveformbull Spectrum envelopendash Imaginary smooth line drawn on top of the
amplitude spectrum
Waveform envelope
From Hillenbrand
Waveform envelope
Time
>
Spectrum envelope
Frequency
Ampl
itude
Thought Question
Can an aperiodic and complex periodic sound have identical
spectrum envelopes
Amplitude Spectrum Window Size
bull ldquoshort-termrdquo vs ldquolong-term averagerdquo amplitude spectrum
ldquoInstantaneousrdquo Amplitude Spectra
(Long Term) Average Amplitude Spectrum
Learning Objectivesbull Describe how the amplitude spectrum and the spectrogram are
relatedbull Identify the axis units of the spectrogrambull Provide some advantages of the spectrogram over the
amplitude spectrumbull Distinguish between a wide band and narrow band spectrogram
and outline the different information each providesbull Distinguish between a harmonic and a formant on a
spectrogrambull Be able to draw stylized (highly simplified) spectrograms based
on spectra and spectrum envelopes
The Spectrogram
Rotate90 degrees
F
AF
A
Building a spectrogram
Rotate it so thatThe amplitude isComing out of thepage
F
A This is really narrow because it is a slice in time
F
Time
Building a spectrogram
Dark bands= amplitudePeaks
Time
Freq
uenc
y
Building a spectrogram
Two main types of spectrograms
bull Narrow-band spectrogramsndash Akin to amplitude spectrums ldquolined uprdquondash Frequency resolution is really sharp
bull Wide-band spectrogramsndash Akin to spectrum envelopes ldquolined uprdquondash Frequency resolution not so sharp
Highlights harmonic structure
Highlights spectrum envelope
Wide vs Narrow Band Spectrograms
Learning Objectives
bull Define an acoustic filterbull Draw and label a frequency response curvebull Draw and differentiate different types of acoustic
filtersbull Define terms such as cutoff frequency center
frequency roll off rate gain and bandwidthbull Define and draw a basic filter system and relate that
to the source-filter theory of speech production
What is an ldquoAcousticrdquo Filter
bull holds back (attenuates) certain sounds and lets other sounds through - selective
Why might we be interested in filters
bull Human vocal tract acts like a frequency selective acoustic filter
bull Human auditory system behaves as a frequency selective filter
bull helps us understand how speech is produced and perceived
Kinds of frequency selective filters
Low-pass filtersndash Lets low frequencies ldquopass throughrdquo and attenuates high
frequencies
High-pass filtersndash Lets high frequencies ldquopass throughrdquo and attenuates low
frequencies
Band-pass filtersndash Lets a particular frequency range ldquopass throughrdquo and
attenuates other frequencies
Low Pass Filters
Frequencylow high
Gai
n
+
-
High Pass Filters
Frequencylow high
Gai
n
+
-
Band Pass Filter
Frequencylow high
Gai
n
+
-
Frequency Response Curve (FRC)
Frequencylow high
Gai
n
+
-
Center frequency
lower cutofffrequency
upper cutoff frequency
passband
3 dB
Operation of a filter on a signal
NOTE Amplitude spectrum describes a soundFrequency response curve describes a filter
Learning Objectivesbull Define resonance free and forced vibrationbull Describe how the pendulum and spring mass models can
help explain resonancebull Outline how mass and stiffness influences the resonant
frequency of a mass spring systembull Outline how acoustic resonators behave like acoustic filtersbull Calculate resonant frequencies of a uniform tube based on
its physical dimensionsbull Describe how the wavelength of the sound determines the
resonant frequency of tube
Free vibration
bull objects tend to vibrate at a characteristic or resonant frequency (RF)
Forced vibration
bull A vibrating system can force a nearby system into vibration
bull The efficiency with which this is accomplished is related to the similarity in the resonant frequency (RF) of the two systems
Forced vibration
bull If the RF of the two systems are the same the amplitude of forced vibration will be large
bull If the RF of the two systems are quite different the amplitude of forced vibration will be small or nonexistent
Resonance refers to
bull The tendency for an object to vibrate at a particular frequency or frequencies
bull The ability of a vibrating system to force another system into vibration
Back to the mass spring model
bull Vibratory frequency of the mass spring determined byndash Massndash Stiffness of the spring
httpphetcoloradoeduensimulationmass-spring-lab
Acoustic Resonance
bull Ideas from mechanical resonance also applies to acoustic systems
bull Acoustic chambers will transmit sound frequencies with more or less efficiency depending upon the physical characteristics
bull Therefore they act as filters passing through (and even amplifying) some frequencies and attentuating others
Acoustic Resonance
bull And since they act as filters they have most of the same features of a filter even though we might use different names
bull Center frequency is often termed the resonant frequency
bull Frequency response curve often termed the resonance curve
Helmholtz Resonator
Actions of a Helmholtz Resonator
Stephen M Tasko
Other Acoustic Resonators Tube Resonators
bull Uniform tubes Factors that influence resonancendash Lengthndash Cross-sectional area along its lengthndash Whether it is closed at either or both ends
Uniform tube closed at one end
Uniform tube closed at one end
Stephen M Tasko
Uniform tube closed at one end
First resonance or formant
F1 = c4lWhere
c=speed of sound (35000 cmsec)l = length of the tube
males ~ 175 cmfemales ~ 14 cm
Higher resonantformant frequencies are odd multiples of F1
For examplebull F1 = (c4l )1
bull F2 = (c4l )3
bull F3 = (c4l )5
Comparing Helmholtz and tube resonators
Resonator Features
Sharply tuned Broadly tuned
Resonator Features
An example of the resonance characteristics of the human vocal tract
Frequency
Gain
SPPA 4030 Speech Science
Topic 1 The Speech Chain
The Speech Chain (Denes amp Pinson 1993)
What information is embedded in the speech signal
Branches of science employed to understand speech communication
Physical Quantities Review An Independent Learning Activity
Assignment 1
Topic 2 The Source-Filter Theory of Speech Production An Intr
Producing Speech
Source-Filter Theory of Speech Production
Vocal tract is a tube that can vary its shape
Source Filter Theory
Same Source Different Filter
Different Source Same Filters
Different Source Same Filters (Human)
Different Source Same Filters (Human) (2)
Different Source Same Filters (Human) (3)
Different Source Same Filters (Human) (4)
Different Source Same Filters (Non-Human)
Different Source Same Filters (Non-Human) (2)
Different Source Same Filters (Non-Human) If it quacks like a
Source Filter Theory Applied Alaryngeal Speech
Source-Filter Theory Applied Esophageal Insufflation Test
Source-Filter Theory Applied Tracheoesophageal (TE) Speech
Source Filter Theory Applied The Talkbox
Source-Filter Theory Applied The Talkbox
Topic 3 A Brief Review of Physical Acoustics
Spring Mass Model
What is sound
Sound-conducting media
Model of air molecule vibration (Time 1)
Model of air molecule vibration (Time 2)
Model of air molecule vibration (Time 3)
Model of air molecule vibration (Time 4)
Model of air molecule vibration (Time 5)
Model of air molecule vibration
Wave action of molecular motion
Amplitude waveform
Amplitude waveform (2)
Where is pressure in this model
Pressure waveform
Measuring Sound
Measuring Sound Signal Amplitude
Measuring Sound Signal Amplitude (2)
What units do we use to measure signal amplitude
Brief Review The decibel scale
Absolute vs relative measurement
Typical reference values
Howeverhellip
Linear vs logarithmic
Linear vs logarithmic (2)
Logarithmic Scale
Logarithmic Scale (2)
Combining the idea of logarithmic and relativehellip
Intensity vs Pressure
Extending the formula to pressure
Measuring Sound Frequencyperiod
Measuring Sound Frequencyperiod (2)
Phase Uniform Circular Motion
Initiating a sound waves that differ only in phase
Spatial variation in pressure wave
Spatial variation in pressure wave
Spatial variation in pressure wave (2)
Relation between frequency and wavelength
Learning Objectives
Graphic representation of sound
Same sound different graphs
Classification of sounds
Simple periodic sound
Simple periodic sound Graphic appearance
Complex periodic sounds
Complex periodic sounds Graphic appearance
Complex periodic sounds Graphic appearance (2)
Glottal Source
Amplitude vs Phase Spectrum
Amplitude vs Phase Spectrum (2)
(Complex) Aperiodic sounds
Aperiodic sounds Graphic appearance
Aperiodic sounds Graphic appearance (2)
Analysis of complex waves
Learning Objectives (2)
The ldquoenveloperdquo of a sound wave
Waveform envelope
Waveform envelope (2)
Spectrum envelope
Thought Question
Amplitude Spectrum Window Size
ldquoInstantaneousrdquo Amplitude Spectra
(Long Term) Average Amplitude Spectrum
Slide 90
Learning Objectives (3)
The Spectrogram
Building a spectrogram
Building a spectrogram
Building a spectrogram (2)
Two main types of spectrograms
Wide vs Narrow Band Spectrograms
Learning Objectives (4)
What is an ldquoAcousticrdquo Filter
Why might we be interested in filters
Kinds of frequency selective filters
Low Pass Filters
High Pass Filters
Band Pass Filter
Frequency Response Curve (FRC)
Operation of a filter on a signal
Learning Objectives (5)
Free vibration
Forced vibration
Forced vibration (2)
Resonance refers to
Back to the mass spring model
Acoustic Resonance
Acoustic Resonance (2)
Helmholtz Resonator
Actions of a Helmholtz Resonator
Other Acoustic Resonators Tube Resonators
Uniform tube closed at one end
Uniform tube closed at one end (2)
Uniform tube closed at one end
Comparing Helmholtz and tube resonators
Slide 122
Slide 123
Producing Speech
bull The vocal tract can be conceived as a set of interconnecting tubes and valves
bull Speech production is achieved through the systematic regulation of air pressures and flows within the vocal tract
Source-Filter Theory of Speech Production
bull The sounds we hear as speech is the product of a sound source that has undergone filtering by the vocal tract
bull source and the filter may be considered to be independent of each other
Vocal tract is a tube that can vary its shape
From Titze (1994)
Source Filter Theory
Source(Phonation)
Filter(Resonator)
Speech(What We Hear)
Input Spectrum Frequency ResponseCurve
Output Spectrum
>
>
Same Source Different Filter
>
>
>
>
Different Source Same Filters
White Noise
>
>
>
>
Different Source Same Filters (Human)
burp
>
>
>
>
Different Source Same Filters (Human)
snore
>
>
>
>
Different Source Same Filters (Human)
Lip buzz
>
>
>
>
Different Source Same Filters (Human)
>
>
>
>
Different Source Same Filters (Non-Human)
sheep
>
>
>
>
Different Source Same Filters (Non-Human)
accordion
>
>
>
>
Different Source Same Filters (Non-Human)If it quacks like a duckhellip
>
>
>
>
Source Filter Theory Applied Alaryngeal Speech
Source-Filter Theory AppliedEsophageal Insufflation Test
Source-Filter Theory AppliedTracheoesophageal (TE) Speech
Source Filter Theory Applied The Talkbox
Source-Filter Theory Applied The Talkbox
httpwwwyoutubecomwatchv=YS3gAVNlceg
Topic 3 A Brief Review of Physical Acoustics
Learning Objectivesbull Outline the physical processes underlying simple harmonic motion using the
mass-spring modelbull Describe the molecular basis of sound wave propagationbull Define the key characteristics of sinusoidal motion including
ndash Amplitude instantaneous peak peak-to-peak root-mean-square (RMS) the decibel scale
ndash Frequencyperiod including units of measurendash Phasendash Wavelength
bull Briefly describe the relation between the sine wave and uniform circular motion
bull Outline the relationship between the frequency and wavelength of a sound wave
Spring Mass Model
bull Mass (inertia)ndash Newtonrsquos first law of motionndash Opposition to
accelerationdecelerationbull Elasticityndash Opposition to displacementndash Rest positionndash Recoil force
bull Complex gt one frequency componentbull Aperiodic Does not repeat itselfbull Frequency components are not systematically
relatedbull May be ndash Continuousndash Transient
Aperiodic sounds Graphic appearance
bull Time domainndash no repeating pattern of pressure change
bull Frequency domainndash the spectrum is dense ndash No ldquopicket fencerdquo
bull Auditory impression sounds lsquonoisyrsquo
Aperiodic sounds Graphic appearance
From Hillenbrand
>
Analysis of complex wavesbull Waves can be summedbull Complex waves are the sum of simple wavesbull Fourier French Mathematician
ndash Any complex waveform may be formed by summing sinusoids of various frequency amplitude and phase
bull Fourier Analysisndash Provides a unique (only one) solution for a given sound signalndash Is reflected in the amplitude and phase spectrum of the signalndash Reveals the building blocks of complex waves which are sinusoids
Learning Objectives
bull Draw and differentiate the waveform and the waveform envelope
bull Draw and differentiate the amplitude spectrum the phase spectrum and the spectrum envelope
bull Differential between short-term spectra and long-term average spectra
The ldquoenveloperdquo of a sound wave
bull Waveform envelopendash imaginary smooth line that follows the peak of the
amplitude of a sound pressure waveformbull Spectrum envelopendash Imaginary smooth line drawn on top of the
amplitude spectrum
Waveform envelope
From Hillenbrand
Waveform envelope
Time
>
Spectrum envelope
Frequency
Ampl
itude
Thought Question
Can an aperiodic and complex periodic sound have identical
spectrum envelopes
Amplitude Spectrum Window Size
bull ldquoshort-termrdquo vs ldquolong-term averagerdquo amplitude spectrum
ldquoInstantaneousrdquo Amplitude Spectra
(Long Term) Average Amplitude Spectrum
Learning Objectivesbull Describe how the amplitude spectrum and the spectrogram are
relatedbull Identify the axis units of the spectrogrambull Provide some advantages of the spectrogram over the
amplitude spectrumbull Distinguish between a wide band and narrow band spectrogram
and outline the different information each providesbull Distinguish between a harmonic and a formant on a
spectrogrambull Be able to draw stylized (highly simplified) spectrograms based
on spectra and spectrum envelopes
The Spectrogram
Rotate90 degrees
F
AF
A
Building a spectrogram
Rotate it so thatThe amplitude isComing out of thepage
F
A This is really narrow because it is a slice in time
F
Time
Building a spectrogram
Dark bands= amplitudePeaks
Time
Freq
uenc
y
Building a spectrogram
Two main types of spectrograms
bull Narrow-band spectrogramsndash Akin to amplitude spectrums ldquolined uprdquondash Frequency resolution is really sharp
bull Wide-band spectrogramsndash Akin to spectrum envelopes ldquolined uprdquondash Frequency resolution not so sharp
Highlights harmonic structure
Highlights spectrum envelope
Wide vs Narrow Band Spectrograms
Learning Objectives
bull Define an acoustic filterbull Draw and label a frequency response curvebull Draw and differentiate different types of acoustic
filtersbull Define terms such as cutoff frequency center
frequency roll off rate gain and bandwidthbull Define and draw a basic filter system and relate that
to the source-filter theory of speech production
What is an ldquoAcousticrdquo Filter
bull holds back (attenuates) certain sounds and lets other sounds through - selective
Why might we be interested in filters
bull Human vocal tract acts like a frequency selective acoustic filter
bull Human auditory system behaves as a frequency selective filter
bull helps us understand how speech is produced and perceived
Kinds of frequency selective filters
Low-pass filtersndash Lets low frequencies ldquopass throughrdquo and attenuates high
frequencies
High-pass filtersndash Lets high frequencies ldquopass throughrdquo and attenuates low
frequencies
Band-pass filtersndash Lets a particular frequency range ldquopass throughrdquo and
attenuates other frequencies
Low Pass Filters
Frequencylow high
Gai
n
+
-
High Pass Filters
Frequencylow high
Gai
n
+
-
Band Pass Filter
Frequencylow high
Gai
n
+
-
Frequency Response Curve (FRC)
Frequencylow high
Gai
n
+
-
Center frequency
lower cutofffrequency
upper cutoff frequency
passband
3 dB
Operation of a filter on a signal
NOTE Amplitude spectrum describes a soundFrequency response curve describes a filter
Learning Objectivesbull Define resonance free and forced vibrationbull Describe how the pendulum and spring mass models can
help explain resonancebull Outline how mass and stiffness influences the resonant
frequency of a mass spring systembull Outline how acoustic resonators behave like acoustic filtersbull Calculate resonant frequencies of a uniform tube based on
its physical dimensionsbull Describe how the wavelength of the sound determines the
resonant frequency of tube
Free vibration
bull objects tend to vibrate at a characteristic or resonant frequency (RF)
Forced vibration
bull A vibrating system can force a nearby system into vibration
bull The efficiency with which this is accomplished is related to the similarity in the resonant frequency (RF) of the two systems
Forced vibration
bull If the RF of the two systems are the same the amplitude of forced vibration will be large
bull If the RF of the two systems are quite different the amplitude of forced vibration will be small or nonexistent
Resonance refers to
bull The tendency for an object to vibrate at a particular frequency or frequencies
bull The ability of a vibrating system to force another system into vibration
Back to the mass spring model
bull Vibratory frequency of the mass spring determined byndash Massndash Stiffness of the spring
httpphetcoloradoeduensimulationmass-spring-lab
Acoustic Resonance
bull Ideas from mechanical resonance also applies to acoustic systems
bull Acoustic chambers will transmit sound frequencies with more or less efficiency depending upon the physical characteristics
bull Therefore they act as filters passing through (and even amplifying) some frequencies and attentuating others
Acoustic Resonance
bull And since they act as filters they have most of the same features of a filter even though we might use different names
bull Center frequency is often termed the resonant frequency
bull Frequency response curve often termed the resonance curve
Helmholtz Resonator
Actions of a Helmholtz Resonator
Stephen M Tasko
Other Acoustic Resonators Tube Resonators
bull Uniform tubes Factors that influence resonancendash Lengthndash Cross-sectional area along its lengthndash Whether it is closed at either or both ends
Uniform tube closed at one end
Uniform tube closed at one end
Stephen M Tasko
Uniform tube closed at one end
First resonance or formant
F1 = c4lWhere
c=speed of sound (35000 cmsec)l = length of the tube
males ~ 175 cmfemales ~ 14 cm
Higher resonantformant frequencies are odd multiples of F1
For examplebull F1 = (c4l )1
bull F2 = (c4l )3
bull F3 = (c4l )5
Comparing Helmholtz and tube resonators
Resonator Features
Sharply tuned Broadly tuned
Resonator Features
An example of the resonance characteristics of the human vocal tract
Frequency
Gain
SPPA 4030 Speech Science
Topic 1 The Speech Chain
The Speech Chain (Denes amp Pinson 1993)
What information is embedded in the speech signal
Branches of science employed to understand speech communication
Physical Quantities Review An Independent Learning Activity
Assignment 1
Topic 2 The Source-Filter Theory of Speech Production An Intr
Producing Speech
Source-Filter Theory of Speech Production
Vocal tract is a tube that can vary its shape
Source Filter Theory
Same Source Different Filter
Different Source Same Filters
Different Source Same Filters (Human)
Different Source Same Filters (Human) (2)
Different Source Same Filters (Human) (3)
Different Source Same Filters (Human) (4)
Different Source Same Filters (Non-Human)
Different Source Same Filters (Non-Human) (2)
Different Source Same Filters (Non-Human) If it quacks like a
Source Filter Theory Applied Alaryngeal Speech
Source-Filter Theory Applied Esophageal Insufflation Test
Source-Filter Theory Applied Tracheoesophageal (TE) Speech
Source Filter Theory Applied The Talkbox
Source-Filter Theory Applied The Talkbox
Topic 3 A Brief Review of Physical Acoustics
Spring Mass Model
What is sound
Sound-conducting media
Model of air molecule vibration (Time 1)
Model of air molecule vibration (Time 2)
Model of air molecule vibration (Time 3)
Model of air molecule vibration (Time 4)
Model of air molecule vibration (Time 5)
Model of air molecule vibration
Wave action of molecular motion
Amplitude waveform
Amplitude waveform (2)
Where is pressure in this model
Pressure waveform
Measuring Sound
Measuring Sound Signal Amplitude
Measuring Sound Signal Amplitude (2)
What units do we use to measure signal amplitude
Brief Review The decibel scale
Absolute vs relative measurement
Typical reference values
Howeverhellip
Linear vs logarithmic
Linear vs logarithmic (2)
Logarithmic Scale
Logarithmic Scale (2)
Combining the idea of logarithmic and relativehellip
Intensity vs Pressure
Extending the formula to pressure
Measuring Sound Frequencyperiod
Measuring Sound Frequencyperiod (2)
Phase Uniform Circular Motion
Initiating a sound waves that differ only in phase
Spatial variation in pressure wave
Spatial variation in pressure wave
Spatial variation in pressure wave (2)
Relation between frequency and wavelength
Learning Objectives
Graphic representation of sound
Same sound different graphs
Classification of sounds
Simple periodic sound
Simple periodic sound Graphic appearance
Complex periodic sounds
Complex periodic sounds Graphic appearance
Complex periodic sounds Graphic appearance (2)
Glottal Source
Amplitude vs Phase Spectrum
Amplitude vs Phase Spectrum (2)
(Complex) Aperiodic sounds
Aperiodic sounds Graphic appearance
Aperiodic sounds Graphic appearance (2)
Analysis of complex waves
Learning Objectives (2)
The ldquoenveloperdquo of a sound wave
Waveform envelope
Waveform envelope (2)
Spectrum envelope
Thought Question
Amplitude Spectrum Window Size
ldquoInstantaneousrdquo Amplitude Spectra
(Long Term) Average Amplitude Spectrum
Slide 90
Learning Objectives (3)
The Spectrogram
Building a spectrogram
Building a spectrogram
Building a spectrogram (2)
Two main types of spectrograms
Wide vs Narrow Band Spectrograms
Learning Objectives (4)
What is an ldquoAcousticrdquo Filter
Why might we be interested in filters
Kinds of frequency selective filters
Low Pass Filters
High Pass Filters
Band Pass Filter
Frequency Response Curve (FRC)
Operation of a filter on a signal
Learning Objectives (5)
Free vibration
Forced vibration
Forced vibration (2)
Resonance refers to
Back to the mass spring model
Acoustic Resonance
Acoustic Resonance (2)
Helmholtz Resonator
Actions of a Helmholtz Resonator
Other Acoustic Resonators Tube Resonators
Uniform tube closed at one end
Uniform tube closed at one end (2)
Uniform tube closed at one end
Comparing Helmholtz and tube resonators
Slide 122
Slide 123
Source-Filter Theory of Speech Production
bull The sounds we hear as speech is the product of a sound source that has undergone filtering by the vocal tract
bull source and the filter may be considered to be independent of each other
Vocal tract is a tube that can vary its shape
From Titze (1994)
Source Filter Theory
Source(Phonation)
Filter(Resonator)
Speech(What We Hear)
Input Spectrum Frequency ResponseCurve
Output Spectrum
>
>
Same Source Different Filter
>
>
>
>
Different Source Same Filters
White Noise
>
>
>
>
Different Source Same Filters (Human)
burp
>
>
>
>
Different Source Same Filters (Human)
snore
>
>
>
>
Different Source Same Filters (Human)
Lip buzz
>
>
>
>
Different Source Same Filters (Human)
>
>
>
>
Different Source Same Filters (Non-Human)
sheep
>
>
>
>
Different Source Same Filters (Non-Human)
accordion
>
>
>
>
Different Source Same Filters (Non-Human)If it quacks like a duckhellip
>
>
>
>
Source Filter Theory Applied Alaryngeal Speech
Source-Filter Theory AppliedEsophageal Insufflation Test
Source-Filter Theory AppliedTracheoesophageal (TE) Speech
Source Filter Theory Applied The Talkbox
Source-Filter Theory Applied The Talkbox
httpwwwyoutubecomwatchv=YS3gAVNlceg
Topic 3 A Brief Review of Physical Acoustics
Learning Objectivesbull Outline the physical processes underlying simple harmonic motion using the
mass-spring modelbull Describe the molecular basis of sound wave propagationbull Define the key characteristics of sinusoidal motion including
ndash Amplitude instantaneous peak peak-to-peak root-mean-square (RMS) the decibel scale
ndash Frequencyperiod including units of measurendash Phasendash Wavelength
bull Briefly describe the relation between the sine wave and uniform circular motion
bull Outline the relationship between the frequency and wavelength of a sound wave
Spring Mass Model
bull Mass (inertia)ndash Newtonrsquos first law of motionndash Opposition to
accelerationdecelerationbull Elasticityndash Opposition to displacementndash Rest positionndash Recoil force
bull Complex gt one frequency componentbull Aperiodic Does not repeat itselfbull Frequency components are not systematically
relatedbull May be ndash Continuousndash Transient
Aperiodic sounds Graphic appearance
bull Time domainndash no repeating pattern of pressure change
bull Frequency domainndash the spectrum is dense ndash No ldquopicket fencerdquo
bull Auditory impression sounds lsquonoisyrsquo
Aperiodic sounds Graphic appearance
From Hillenbrand
>
Analysis of complex wavesbull Waves can be summedbull Complex waves are the sum of simple wavesbull Fourier French Mathematician
ndash Any complex waveform may be formed by summing sinusoids of various frequency amplitude and phase
bull Fourier Analysisndash Provides a unique (only one) solution for a given sound signalndash Is reflected in the amplitude and phase spectrum of the signalndash Reveals the building blocks of complex waves which are sinusoids
Learning Objectives
bull Draw and differentiate the waveform and the waveform envelope
bull Draw and differentiate the amplitude spectrum the phase spectrum and the spectrum envelope
bull Differential between short-term spectra and long-term average spectra
The ldquoenveloperdquo of a sound wave
bull Waveform envelopendash imaginary smooth line that follows the peak of the
amplitude of a sound pressure waveformbull Spectrum envelopendash Imaginary smooth line drawn on top of the
amplitude spectrum
Waveform envelope
From Hillenbrand
Waveform envelope
Time
>
Spectrum envelope
Frequency
Ampl
itude
Thought Question
Can an aperiodic and complex periodic sound have identical
spectrum envelopes
Amplitude Spectrum Window Size
bull ldquoshort-termrdquo vs ldquolong-term averagerdquo amplitude spectrum
ldquoInstantaneousrdquo Amplitude Spectra
(Long Term) Average Amplitude Spectrum
Learning Objectivesbull Describe how the amplitude spectrum and the spectrogram are
relatedbull Identify the axis units of the spectrogrambull Provide some advantages of the spectrogram over the
amplitude spectrumbull Distinguish between a wide band and narrow band spectrogram
and outline the different information each providesbull Distinguish between a harmonic and a formant on a
spectrogrambull Be able to draw stylized (highly simplified) spectrograms based
on spectra and spectrum envelopes
The Spectrogram
Rotate90 degrees
F
AF
A
Building a spectrogram
Rotate it so thatThe amplitude isComing out of thepage
F
A This is really narrow because it is a slice in time
F
Time
Building a spectrogram
Dark bands= amplitudePeaks
Time
Freq
uenc
y
Building a spectrogram
Two main types of spectrograms
bull Narrow-band spectrogramsndash Akin to amplitude spectrums ldquolined uprdquondash Frequency resolution is really sharp
bull Wide-band spectrogramsndash Akin to spectrum envelopes ldquolined uprdquondash Frequency resolution not so sharp
Highlights harmonic structure
Highlights spectrum envelope
Wide vs Narrow Band Spectrograms
Learning Objectives
bull Define an acoustic filterbull Draw and label a frequency response curvebull Draw and differentiate different types of acoustic
filtersbull Define terms such as cutoff frequency center
frequency roll off rate gain and bandwidthbull Define and draw a basic filter system and relate that
to the source-filter theory of speech production
What is an ldquoAcousticrdquo Filter
bull holds back (attenuates) certain sounds and lets other sounds through - selective
Why might we be interested in filters
bull Human vocal tract acts like a frequency selective acoustic filter
bull Human auditory system behaves as a frequency selective filter
bull helps us understand how speech is produced and perceived
Kinds of frequency selective filters
Low-pass filtersndash Lets low frequencies ldquopass throughrdquo and attenuates high
frequencies
High-pass filtersndash Lets high frequencies ldquopass throughrdquo and attenuates low
frequencies
Band-pass filtersndash Lets a particular frequency range ldquopass throughrdquo and
attenuates other frequencies
Low Pass Filters
Frequencylow high
Gai
n
+
-
High Pass Filters
Frequencylow high
Gai
n
+
-
Band Pass Filter
Frequencylow high
Gai
n
+
-
Frequency Response Curve (FRC)
Frequencylow high
Gai
n
+
-
Center frequency
lower cutofffrequency
upper cutoff frequency
passband
3 dB
Operation of a filter on a signal
NOTE Amplitude spectrum describes a soundFrequency response curve describes a filter
Learning Objectivesbull Define resonance free and forced vibrationbull Describe how the pendulum and spring mass models can
help explain resonancebull Outline how mass and stiffness influences the resonant
frequency of a mass spring systembull Outline how acoustic resonators behave like acoustic filtersbull Calculate resonant frequencies of a uniform tube based on
its physical dimensionsbull Describe how the wavelength of the sound determines the
resonant frequency of tube
Free vibration
bull objects tend to vibrate at a characteristic or resonant frequency (RF)
Forced vibration
bull A vibrating system can force a nearby system into vibration
bull The efficiency with which this is accomplished is related to the similarity in the resonant frequency (RF) of the two systems
Forced vibration
bull If the RF of the two systems are the same the amplitude of forced vibration will be large
bull If the RF of the two systems are quite different the amplitude of forced vibration will be small or nonexistent
Resonance refers to
bull The tendency for an object to vibrate at a particular frequency or frequencies
bull The ability of a vibrating system to force another system into vibration
Back to the mass spring model
bull Vibratory frequency of the mass spring determined byndash Massndash Stiffness of the spring
httpphetcoloradoeduensimulationmass-spring-lab
Acoustic Resonance
bull Ideas from mechanical resonance also applies to acoustic systems
bull Acoustic chambers will transmit sound frequencies with more or less efficiency depending upon the physical characteristics
bull Therefore they act as filters passing through (and even amplifying) some frequencies and attentuating others
Acoustic Resonance
bull And since they act as filters they have most of the same features of a filter even though we might use different names
bull Center frequency is often termed the resonant frequency
bull Frequency response curve often termed the resonance curve
Helmholtz Resonator
Actions of a Helmholtz Resonator
Stephen M Tasko
Other Acoustic Resonators Tube Resonators
bull Uniform tubes Factors that influence resonancendash Lengthndash Cross-sectional area along its lengthndash Whether it is closed at either or both ends
Uniform tube closed at one end
Uniform tube closed at one end
Stephen M Tasko
Uniform tube closed at one end
First resonance or formant
F1 = c4lWhere
c=speed of sound (35000 cmsec)l = length of the tube
males ~ 175 cmfemales ~ 14 cm
Higher resonantformant frequencies are odd multiples of F1
For examplebull F1 = (c4l )1
bull F2 = (c4l )3
bull F3 = (c4l )5
Comparing Helmholtz and tube resonators
Resonator Features
Sharply tuned Broadly tuned
Resonator Features
An example of the resonance characteristics of the human vocal tract
Frequency
Gain
SPPA 4030 Speech Science
Topic 1 The Speech Chain
The Speech Chain (Denes amp Pinson 1993)
What information is embedded in the speech signal
Branches of science employed to understand speech communication
Physical Quantities Review An Independent Learning Activity
Assignment 1
Topic 2 The Source-Filter Theory of Speech Production An Intr
Producing Speech
Source-Filter Theory of Speech Production
Vocal tract is a tube that can vary its shape
Source Filter Theory
Same Source Different Filter
Different Source Same Filters
Different Source Same Filters (Human)
Different Source Same Filters (Human) (2)
Different Source Same Filters (Human) (3)
Different Source Same Filters (Human) (4)
Different Source Same Filters (Non-Human)
Different Source Same Filters (Non-Human) (2)
Different Source Same Filters (Non-Human) If it quacks like a
Source Filter Theory Applied Alaryngeal Speech
Source-Filter Theory Applied Esophageal Insufflation Test
Source-Filter Theory Applied Tracheoesophageal (TE) Speech
Source Filter Theory Applied The Talkbox
Source-Filter Theory Applied The Talkbox
Topic 3 A Brief Review of Physical Acoustics
Spring Mass Model
What is sound
Sound-conducting media
Model of air molecule vibration (Time 1)
Model of air molecule vibration (Time 2)
Model of air molecule vibration (Time 3)
Model of air molecule vibration (Time 4)
Model of air molecule vibration (Time 5)
Model of air molecule vibration
Wave action of molecular motion
Amplitude waveform
Amplitude waveform (2)
Where is pressure in this model
Pressure waveform
Measuring Sound
Measuring Sound Signal Amplitude
Measuring Sound Signal Amplitude (2)
What units do we use to measure signal amplitude
Brief Review The decibel scale
Absolute vs relative measurement
Typical reference values
Howeverhellip
Linear vs logarithmic
Linear vs logarithmic (2)
Logarithmic Scale
Logarithmic Scale (2)
Combining the idea of logarithmic and relativehellip
Intensity vs Pressure
Extending the formula to pressure
Measuring Sound Frequencyperiod
Measuring Sound Frequencyperiod (2)
Phase Uniform Circular Motion
Initiating a sound waves that differ only in phase
Spatial variation in pressure wave
Spatial variation in pressure wave
Spatial variation in pressure wave (2)
Relation between frequency and wavelength
Learning Objectives
Graphic representation of sound
Same sound different graphs
Classification of sounds
Simple periodic sound
Simple periodic sound Graphic appearance
Complex periodic sounds
Complex periodic sounds Graphic appearance
Complex periodic sounds Graphic appearance (2)
Glottal Source
Amplitude vs Phase Spectrum
Amplitude vs Phase Spectrum (2)
(Complex) Aperiodic sounds
Aperiodic sounds Graphic appearance
Aperiodic sounds Graphic appearance (2)
Analysis of complex waves
Learning Objectives (2)
The ldquoenveloperdquo of a sound wave
Waveform envelope
Waveform envelope (2)
Spectrum envelope
Thought Question
Amplitude Spectrum Window Size
ldquoInstantaneousrdquo Amplitude Spectra
(Long Term) Average Amplitude Spectrum
Slide 90
Learning Objectives (3)
The Spectrogram
Building a spectrogram
Building a spectrogram
Building a spectrogram (2)
Two main types of spectrograms
Wide vs Narrow Band Spectrograms
Learning Objectives (4)
What is an ldquoAcousticrdquo Filter
Why might we be interested in filters
Kinds of frequency selective filters
Low Pass Filters
High Pass Filters
Band Pass Filter
Frequency Response Curve (FRC)
Operation of a filter on a signal
Learning Objectives (5)
Free vibration
Forced vibration
Forced vibration (2)
Resonance refers to
Back to the mass spring model
Acoustic Resonance
Acoustic Resonance (2)
Helmholtz Resonator
Actions of a Helmholtz Resonator
Other Acoustic Resonators Tube Resonators
Uniform tube closed at one end
Uniform tube closed at one end (2)
Uniform tube closed at one end
Comparing Helmholtz and tube resonators
Slide 122
Slide 123
Vocal tract is a tube that can vary its shape
From Titze (1994)
Source Filter Theory
Source(Phonation)
Filter(Resonator)
Speech(What We Hear)
Input Spectrum Frequency ResponseCurve
Output Spectrum
>
>
Same Source Different Filter
>
>
>
>
Different Source Same Filters
White Noise
>
>
>
>
Different Source Same Filters (Human)
burp
>
>
>
>
Different Source Same Filters (Human)
snore
>
>
>
>
Different Source Same Filters (Human)
Lip buzz
>
>
>
>
Different Source Same Filters (Human)
>
>
>
>
Different Source Same Filters (Non-Human)
sheep
>
>
>
>
Different Source Same Filters (Non-Human)
accordion
>
>
>
>
Different Source Same Filters (Non-Human)If it quacks like a duckhellip
>
>
>
>
Source Filter Theory Applied Alaryngeal Speech
Source-Filter Theory AppliedEsophageal Insufflation Test
Source-Filter Theory AppliedTracheoesophageal (TE) Speech
Source Filter Theory Applied The Talkbox
Source-Filter Theory Applied The Talkbox
httpwwwyoutubecomwatchv=YS3gAVNlceg
Topic 3 A Brief Review of Physical Acoustics
Learning Objectivesbull Outline the physical processes underlying simple harmonic motion using the
mass-spring modelbull Describe the molecular basis of sound wave propagationbull Define the key characteristics of sinusoidal motion including
ndash Amplitude instantaneous peak peak-to-peak root-mean-square (RMS) the decibel scale
ndash Frequencyperiod including units of measurendash Phasendash Wavelength
bull Briefly describe the relation between the sine wave and uniform circular motion
bull Outline the relationship between the frequency and wavelength of a sound wave
Spring Mass Model
bull Mass (inertia)ndash Newtonrsquos first law of motionndash Opposition to
accelerationdecelerationbull Elasticityndash Opposition to displacementndash Rest positionndash Recoil force
bull Complex gt one frequency componentbull Aperiodic Does not repeat itselfbull Frequency components are not systematically
relatedbull May be ndash Continuousndash Transient
Aperiodic sounds Graphic appearance
bull Time domainndash no repeating pattern of pressure change
bull Frequency domainndash the spectrum is dense ndash No ldquopicket fencerdquo
bull Auditory impression sounds lsquonoisyrsquo
Aperiodic sounds Graphic appearance
From Hillenbrand
>
Analysis of complex wavesbull Waves can be summedbull Complex waves are the sum of simple wavesbull Fourier French Mathematician
ndash Any complex waveform may be formed by summing sinusoids of various frequency amplitude and phase
bull Fourier Analysisndash Provides a unique (only one) solution for a given sound signalndash Is reflected in the amplitude and phase spectrum of the signalndash Reveals the building blocks of complex waves which are sinusoids
Learning Objectives
bull Draw and differentiate the waveform and the waveform envelope
bull Draw and differentiate the amplitude spectrum the phase spectrum and the spectrum envelope
bull Differential between short-term spectra and long-term average spectra
The ldquoenveloperdquo of a sound wave
bull Waveform envelopendash imaginary smooth line that follows the peak of the
amplitude of a sound pressure waveformbull Spectrum envelopendash Imaginary smooth line drawn on top of the
amplitude spectrum
Waveform envelope
From Hillenbrand
Waveform envelope
Time
>
Spectrum envelope
Frequency
Ampl
itude
Thought Question
Can an aperiodic and complex periodic sound have identical
spectrum envelopes
Amplitude Spectrum Window Size
bull ldquoshort-termrdquo vs ldquolong-term averagerdquo amplitude spectrum
ldquoInstantaneousrdquo Amplitude Spectra
(Long Term) Average Amplitude Spectrum
Learning Objectivesbull Describe how the amplitude spectrum and the spectrogram are
relatedbull Identify the axis units of the spectrogrambull Provide some advantages of the spectrogram over the
amplitude spectrumbull Distinguish between a wide band and narrow band spectrogram
and outline the different information each providesbull Distinguish between a harmonic and a formant on a
spectrogrambull Be able to draw stylized (highly simplified) spectrograms based
on spectra and spectrum envelopes
The Spectrogram
Rotate90 degrees
F
AF
A
Building a spectrogram
Rotate it so thatThe amplitude isComing out of thepage
F
A This is really narrow because it is a slice in time
F
Time
Building a spectrogram
Dark bands= amplitudePeaks
Time
Freq
uenc
y
Building a spectrogram
Two main types of spectrograms
bull Narrow-band spectrogramsndash Akin to amplitude spectrums ldquolined uprdquondash Frequency resolution is really sharp
bull Wide-band spectrogramsndash Akin to spectrum envelopes ldquolined uprdquondash Frequency resolution not so sharp
Highlights harmonic structure
Highlights spectrum envelope
Wide vs Narrow Band Spectrograms
Learning Objectives
bull Define an acoustic filterbull Draw and label a frequency response curvebull Draw and differentiate different types of acoustic
filtersbull Define terms such as cutoff frequency center
frequency roll off rate gain and bandwidthbull Define and draw a basic filter system and relate that
to the source-filter theory of speech production
What is an ldquoAcousticrdquo Filter
bull holds back (attenuates) certain sounds and lets other sounds through - selective
Why might we be interested in filters
bull Human vocal tract acts like a frequency selective acoustic filter
bull Human auditory system behaves as a frequency selective filter
bull helps us understand how speech is produced and perceived
Kinds of frequency selective filters
Low-pass filtersndash Lets low frequencies ldquopass throughrdquo and attenuates high
frequencies
High-pass filtersndash Lets high frequencies ldquopass throughrdquo and attenuates low
frequencies
Band-pass filtersndash Lets a particular frequency range ldquopass throughrdquo and
attenuates other frequencies
Low Pass Filters
Frequencylow high
Gai
n
+
-
High Pass Filters
Frequencylow high
Gai
n
+
-
Band Pass Filter
Frequencylow high
Gai
n
+
-
Frequency Response Curve (FRC)
Frequencylow high
Gai
n
+
-
Center frequency
lower cutofffrequency
upper cutoff frequency
passband
3 dB
Operation of a filter on a signal
NOTE Amplitude spectrum describes a soundFrequency response curve describes a filter
Learning Objectivesbull Define resonance free and forced vibrationbull Describe how the pendulum and spring mass models can
help explain resonancebull Outline how mass and stiffness influences the resonant
frequency of a mass spring systembull Outline how acoustic resonators behave like acoustic filtersbull Calculate resonant frequencies of a uniform tube based on
its physical dimensionsbull Describe how the wavelength of the sound determines the
resonant frequency of tube
Free vibration
bull objects tend to vibrate at a characteristic or resonant frequency (RF)
Forced vibration
bull A vibrating system can force a nearby system into vibration
bull The efficiency with which this is accomplished is related to the similarity in the resonant frequency (RF) of the two systems
Forced vibration
bull If the RF of the two systems are the same the amplitude of forced vibration will be large
bull If the RF of the two systems are quite different the amplitude of forced vibration will be small or nonexistent
Resonance refers to
bull The tendency for an object to vibrate at a particular frequency or frequencies
bull The ability of a vibrating system to force another system into vibration
Back to the mass spring model
bull Vibratory frequency of the mass spring determined byndash Massndash Stiffness of the spring
httpphetcoloradoeduensimulationmass-spring-lab
Acoustic Resonance
bull Ideas from mechanical resonance also applies to acoustic systems
bull Acoustic chambers will transmit sound frequencies with more or less efficiency depending upon the physical characteristics
bull Therefore they act as filters passing through (and even amplifying) some frequencies and attentuating others
Acoustic Resonance
bull And since they act as filters they have most of the same features of a filter even though we might use different names
bull Center frequency is often termed the resonant frequency
bull Frequency response curve often termed the resonance curve
Helmholtz Resonator
Actions of a Helmholtz Resonator
Stephen M Tasko
Other Acoustic Resonators Tube Resonators
bull Uniform tubes Factors that influence resonancendash Lengthndash Cross-sectional area along its lengthndash Whether it is closed at either or both ends
Uniform tube closed at one end
Uniform tube closed at one end
Stephen M Tasko
Uniform tube closed at one end
First resonance or formant
F1 = c4lWhere
c=speed of sound (35000 cmsec)l = length of the tube
males ~ 175 cmfemales ~ 14 cm
Higher resonantformant frequencies are odd multiples of F1
For examplebull F1 = (c4l )1
bull F2 = (c4l )3
bull F3 = (c4l )5
Comparing Helmholtz and tube resonators
Resonator Features
Sharply tuned Broadly tuned
Resonator Features
An example of the resonance characteristics of the human vocal tract
Frequency
Gain
SPPA 4030 Speech Science
Topic 1 The Speech Chain
The Speech Chain (Denes amp Pinson 1993)
What information is embedded in the speech signal
Branches of science employed to understand speech communication
Physical Quantities Review An Independent Learning Activity
Assignment 1
Topic 2 The Source-Filter Theory of Speech Production An Intr
Producing Speech
Source-Filter Theory of Speech Production
Vocal tract is a tube that can vary its shape
Source Filter Theory
Same Source Different Filter
Different Source Same Filters
Different Source Same Filters (Human)
Different Source Same Filters (Human) (2)
Different Source Same Filters (Human) (3)
Different Source Same Filters (Human) (4)
Different Source Same Filters (Non-Human)
Different Source Same Filters (Non-Human) (2)
Different Source Same Filters (Non-Human) If it quacks like a
Source Filter Theory Applied Alaryngeal Speech
Source-Filter Theory Applied Esophageal Insufflation Test
Source-Filter Theory Applied Tracheoesophageal (TE) Speech
Source Filter Theory Applied The Talkbox
Source-Filter Theory Applied The Talkbox
Topic 3 A Brief Review of Physical Acoustics
Spring Mass Model
What is sound
Sound-conducting media
Model of air molecule vibration (Time 1)
Model of air molecule vibration (Time 2)
Model of air molecule vibration (Time 3)
Model of air molecule vibration (Time 4)
Model of air molecule vibration (Time 5)
Model of air molecule vibration
Wave action of molecular motion
Amplitude waveform
Amplitude waveform (2)
Where is pressure in this model
Pressure waveform
Measuring Sound
Measuring Sound Signal Amplitude
Measuring Sound Signal Amplitude (2)
What units do we use to measure signal amplitude
Brief Review The decibel scale
Absolute vs relative measurement
Typical reference values
Howeverhellip
Linear vs logarithmic
Linear vs logarithmic (2)
Logarithmic Scale
Logarithmic Scale (2)
Combining the idea of logarithmic and relativehellip
Intensity vs Pressure
Extending the formula to pressure
Measuring Sound Frequencyperiod
Measuring Sound Frequencyperiod (2)
Phase Uniform Circular Motion
Initiating a sound waves that differ only in phase
Spatial variation in pressure wave
Spatial variation in pressure wave
Spatial variation in pressure wave (2)
Relation between frequency and wavelength
Learning Objectives
Graphic representation of sound
Same sound different graphs
Classification of sounds
Simple periodic sound
Simple periodic sound Graphic appearance
Complex periodic sounds
Complex periodic sounds Graphic appearance
Complex periodic sounds Graphic appearance (2)
Glottal Source
Amplitude vs Phase Spectrum
Amplitude vs Phase Spectrum (2)
(Complex) Aperiodic sounds
Aperiodic sounds Graphic appearance
Aperiodic sounds Graphic appearance (2)
Analysis of complex waves
Learning Objectives (2)
The ldquoenveloperdquo of a sound wave
Waveform envelope
Waveform envelope (2)
Spectrum envelope
Thought Question
Amplitude Spectrum Window Size
ldquoInstantaneousrdquo Amplitude Spectra
(Long Term) Average Amplitude Spectrum
Slide 90
Learning Objectives (3)
The Spectrogram
Building a spectrogram
Building a spectrogram
Building a spectrogram (2)
Two main types of spectrograms
Wide vs Narrow Band Spectrograms
Learning Objectives (4)
What is an ldquoAcousticrdquo Filter
Why might we be interested in filters
Kinds of frequency selective filters
Low Pass Filters
High Pass Filters
Band Pass Filter
Frequency Response Curve (FRC)
Operation of a filter on a signal
Learning Objectives (5)
Free vibration
Forced vibration
Forced vibration (2)
Resonance refers to
Back to the mass spring model
Acoustic Resonance
Acoustic Resonance (2)
Helmholtz Resonator
Actions of a Helmholtz Resonator
Other Acoustic Resonators Tube Resonators
Uniform tube closed at one end
Uniform tube closed at one end (2)
Uniform tube closed at one end
Comparing Helmholtz and tube resonators
Slide 122
Slide 123
Source Filter Theory
Source(Phonation)
Filter(Resonator)
Speech(What We Hear)
Input Spectrum Frequency ResponseCurve
Output Spectrum
>
>
Same Source Different Filter
>
>
>
>
Different Source Same Filters
White Noise
>
>
>
>
Different Source Same Filters (Human)
burp
>
>
>
>
Different Source Same Filters (Human)
snore
>
>
>
>
Different Source Same Filters (Human)
Lip buzz
>
>
>
>
Different Source Same Filters (Human)
>
>
>
>
Different Source Same Filters (Non-Human)
sheep
>
>
>
>
Different Source Same Filters (Non-Human)
accordion
>
>
>
>
Different Source Same Filters (Non-Human)If it quacks like a duckhellip
>
>
>
>
Source Filter Theory Applied Alaryngeal Speech
Source-Filter Theory AppliedEsophageal Insufflation Test
Source-Filter Theory AppliedTracheoesophageal (TE) Speech
Source Filter Theory Applied The Talkbox
Source-Filter Theory Applied The Talkbox
httpwwwyoutubecomwatchv=YS3gAVNlceg
Topic 3 A Brief Review of Physical Acoustics
Learning Objectivesbull Outline the physical processes underlying simple harmonic motion using the
mass-spring modelbull Describe the molecular basis of sound wave propagationbull Define the key characteristics of sinusoidal motion including
ndash Amplitude instantaneous peak peak-to-peak root-mean-square (RMS) the decibel scale
ndash Frequencyperiod including units of measurendash Phasendash Wavelength
bull Briefly describe the relation between the sine wave and uniform circular motion
bull Outline the relationship between the frequency and wavelength of a sound wave
Spring Mass Model
bull Mass (inertia)ndash Newtonrsquos first law of motionndash Opposition to
accelerationdecelerationbull Elasticityndash Opposition to displacementndash Rest positionndash Recoil force
bull Complex gt one frequency componentbull Aperiodic Does not repeat itselfbull Frequency components are not systematically
relatedbull May be ndash Continuousndash Transient
Aperiodic sounds Graphic appearance
bull Time domainndash no repeating pattern of pressure change
bull Frequency domainndash the spectrum is dense ndash No ldquopicket fencerdquo
bull Auditory impression sounds lsquonoisyrsquo
Aperiodic sounds Graphic appearance
From Hillenbrand
>
Analysis of complex wavesbull Waves can be summedbull Complex waves are the sum of simple wavesbull Fourier French Mathematician
ndash Any complex waveform may be formed by summing sinusoids of various frequency amplitude and phase
bull Fourier Analysisndash Provides a unique (only one) solution for a given sound signalndash Is reflected in the amplitude and phase spectrum of the signalndash Reveals the building blocks of complex waves which are sinusoids
Learning Objectives
bull Draw and differentiate the waveform and the waveform envelope
bull Draw and differentiate the amplitude spectrum the phase spectrum and the spectrum envelope
bull Differential between short-term spectra and long-term average spectra
The ldquoenveloperdquo of a sound wave
bull Waveform envelopendash imaginary smooth line that follows the peak of the
amplitude of a sound pressure waveformbull Spectrum envelopendash Imaginary smooth line drawn on top of the
amplitude spectrum
Waveform envelope
From Hillenbrand
Waveform envelope
Time
>
Spectrum envelope
Frequency
Ampl
itude
Thought Question
Can an aperiodic and complex periodic sound have identical
spectrum envelopes
Amplitude Spectrum Window Size
bull ldquoshort-termrdquo vs ldquolong-term averagerdquo amplitude spectrum
ldquoInstantaneousrdquo Amplitude Spectra
(Long Term) Average Amplitude Spectrum
Learning Objectivesbull Describe how the amplitude spectrum and the spectrogram are
relatedbull Identify the axis units of the spectrogrambull Provide some advantages of the spectrogram over the
amplitude spectrumbull Distinguish between a wide band and narrow band spectrogram
and outline the different information each providesbull Distinguish between a harmonic and a formant on a
spectrogrambull Be able to draw stylized (highly simplified) spectrograms based
on spectra and spectrum envelopes
The Spectrogram
Rotate90 degrees
F
AF
A
Building a spectrogram
Rotate it so thatThe amplitude isComing out of thepage
F
A This is really narrow because it is a slice in time
F
Time
Building a spectrogram
Dark bands= amplitudePeaks
Time
Freq
uenc
y
Building a spectrogram
Two main types of spectrograms
bull Narrow-band spectrogramsndash Akin to amplitude spectrums ldquolined uprdquondash Frequency resolution is really sharp
bull Wide-band spectrogramsndash Akin to spectrum envelopes ldquolined uprdquondash Frequency resolution not so sharp
Highlights harmonic structure
Highlights spectrum envelope
Wide vs Narrow Band Spectrograms
Learning Objectives
bull Define an acoustic filterbull Draw and label a frequency response curvebull Draw and differentiate different types of acoustic
filtersbull Define terms such as cutoff frequency center
frequency roll off rate gain and bandwidthbull Define and draw a basic filter system and relate that
to the source-filter theory of speech production
What is an ldquoAcousticrdquo Filter
bull holds back (attenuates) certain sounds and lets other sounds through - selective
Why might we be interested in filters
bull Human vocal tract acts like a frequency selective acoustic filter
bull Human auditory system behaves as a frequency selective filter
bull helps us understand how speech is produced and perceived
Kinds of frequency selective filters
Low-pass filtersndash Lets low frequencies ldquopass throughrdquo and attenuates high
frequencies
High-pass filtersndash Lets high frequencies ldquopass throughrdquo and attenuates low
frequencies
Band-pass filtersndash Lets a particular frequency range ldquopass throughrdquo and
attenuates other frequencies
Low Pass Filters
Frequencylow high
Gai
n
+
-
High Pass Filters
Frequencylow high
Gai
n
+
-
Band Pass Filter
Frequencylow high
Gai
n
+
-
Frequency Response Curve (FRC)
Frequencylow high
Gai
n
+
-
Center frequency
lower cutofffrequency
upper cutoff frequency
passband
3 dB
Operation of a filter on a signal
NOTE Amplitude spectrum describes a soundFrequency response curve describes a filter
Learning Objectivesbull Define resonance free and forced vibrationbull Describe how the pendulum and spring mass models can
help explain resonancebull Outline how mass and stiffness influences the resonant
frequency of a mass spring systembull Outline how acoustic resonators behave like acoustic filtersbull Calculate resonant frequencies of a uniform tube based on
its physical dimensionsbull Describe how the wavelength of the sound determines the
resonant frequency of tube
Free vibration
bull objects tend to vibrate at a characteristic or resonant frequency (RF)
Forced vibration
bull A vibrating system can force a nearby system into vibration
bull The efficiency with which this is accomplished is related to the similarity in the resonant frequency (RF) of the two systems
Forced vibration
bull If the RF of the two systems are the same the amplitude of forced vibration will be large
bull If the RF of the two systems are quite different the amplitude of forced vibration will be small or nonexistent
Resonance refers to
bull The tendency for an object to vibrate at a particular frequency or frequencies
bull The ability of a vibrating system to force another system into vibration
Back to the mass spring model
bull Vibratory frequency of the mass spring determined byndash Massndash Stiffness of the spring
httpphetcoloradoeduensimulationmass-spring-lab
Acoustic Resonance
bull Ideas from mechanical resonance also applies to acoustic systems
bull Acoustic chambers will transmit sound frequencies with more or less efficiency depending upon the physical characteristics
bull Therefore they act as filters passing through (and even amplifying) some frequencies and attentuating others
Acoustic Resonance
bull And since they act as filters they have most of the same features of a filter even though we might use different names
bull Center frequency is often termed the resonant frequency
bull Frequency response curve often termed the resonance curve
Helmholtz Resonator
Actions of a Helmholtz Resonator
Stephen M Tasko
Other Acoustic Resonators Tube Resonators
bull Uniform tubes Factors that influence resonancendash Lengthndash Cross-sectional area along its lengthndash Whether it is closed at either or both ends
Uniform tube closed at one end
Uniform tube closed at one end
Stephen M Tasko
Uniform tube closed at one end
First resonance or formant
F1 = c4lWhere
c=speed of sound (35000 cmsec)l = length of the tube
males ~ 175 cmfemales ~ 14 cm
Higher resonantformant frequencies are odd multiples of F1
For examplebull F1 = (c4l )1
bull F2 = (c4l )3
bull F3 = (c4l )5
Comparing Helmholtz and tube resonators
Resonator Features
Sharply tuned Broadly tuned
Resonator Features
An example of the resonance characteristics of the human vocal tract
Frequency
Gain
SPPA 4030 Speech Science
Topic 1 The Speech Chain
The Speech Chain (Denes amp Pinson 1993)
What information is embedded in the speech signal
Branches of science employed to understand speech communication
Physical Quantities Review An Independent Learning Activity
Assignment 1
Topic 2 The Source-Filter Theory of Speech Production An Intr
Producing Speech
Source-Filter Theory of Speech Production
Vocal tract is a tube that can vary its shape
Source Filter Theory
Same Source Different Filter
Different Source Same Filters
Different Source Same Filters (Human)
Different Source Same Filters (Human) (2)
Different Source Same Filters (Human) (3)
Different Source Same Filters (Human) (4)
Different Source Same Filters (Non-Human)
Different Source Same Filters (Non-Human) (2)
Different Source Same Filters (Non-Human) If it quacks like a
Source Filter Theory Applied Alaryngeal Speech
Source-Filter Theory Applied Esophageal Insufflation Test
Source-Filter Theory Applied Tracheoesophageal (TE) Speech
Source Filter Theory Applied The Talkbox
Source-Filter Theory Applied The Talkbox
Topic 3 A Brief Review of Physical Acoustics
Spring Mass Model
What is sound
Sound-conducting media
Model of air molecule vibration (Time 1)
Model of air molecule vibration (Time 2)
Model of air molecule vibration (Time 3)
Model of air molecule vibration (Time 4)
Model of air molecule vibration (Time 5)
Model of air molecule vibration
Wave action of molecular motion
Amplitude waveform
Amplitude waveform (2)
Where is pressure in this model
Pressure waveform
Measuring Sound
Measuring Sound Signal Amplitude
Measuring Sound Signal Amplitude (2)
What units do we use to measure signal amplitude
Brief Review The decibel scale
Absolute vs relative measurement
Typical reference values
Howeverhellip
Linear vs logarithmic
Linear vs logarithmic (2)
Logarithmic Scale
Logarithmic Scale (2)
Combining the idea of logarithmic and relativehellip
Intensity vs Pressure
Extending the formula to pressure
Measuring Sound Frequencyperiod
Measuring Sound Frequencyperiod (2)
Phase Uniform Circular Motion
Initiating a sound waves that differ only in phase
Spatial variation in pressure wave
Spatial variation in pressure wave
Spatial variation in pressure wave (2)
Relation between frequency and wavelength
Learning Objectives
Graphic representation of sound
Same sound different graphs
Classification of sounds
Simple periodic sound
Simple periodic sound Graphic appearance
Complex periodic sounds
Complex periodic sounds Graphic appearance
Complex periodic sounds Graphic appearance (2)
Glottal Source
Amplitude vs Phase Spectrum
Amplitude vs Phase Spectrum (2)
(Complex) Aperiodic sounds
Aperiodic sounds Graphic appearance
Aperiodic sounds Graphic appearance (2)
Analysis of complex waves
Learning Objectives (2)
The ldquoenveloperdquo of a sound wave
Waveform envelope
Waveform envelope (2)
Spectrum envelope
Thought Question
Amplitude Spectrum Window Size
ldquoInstantaneousrdquo Amplitude Spectra
(Long Term) Average Amplitude Spectrum
Slide 90
Learning Objectives (3)
The Spectrogram
Building a spectrogram
Building a spectrogram
Building a spectrogram (2)
Two main types of spectrograms
Wide vs Narrow Band Spectrograms
Learning Objectives (4)
What is an ldquoAcousticrdquo Filter
Why might we be interested in filters
Kinds of frequency selective filters
Low Pass Filters
High Pass Filters
Band Pass Filter
Frequency Response Curve (FRC)
Operation of a filter on a signal
Learning Objectives (5)
Free vibration
Forced vibration
Forced vibration (2)
Resonance refers to
Back to the mass spring model
Acoustic Resonance
Acoustic Resonance (2)
Helmholtz Resonator
Actions of a Helmholtz Resonator
Other Acoustic Resonators Tube Resonators
Uniform tube closed at one end
Uniform tube closed at one end (2)
Uniform tube closed at one end
Comparing Helmholtz and tube resonators
Slide 122
Slide 123
Same Source Different Filter
>
>
>
>
Different Source Same Filters
White Noise
>
>
>
>
Different Source Same Filters (Human)
burp
>
>
>
>
Different Source Same Filters (Human)
snore
>
>
>
>
Different Source Same Filters (Human)
Lip buzz
>
>
>
>
Different Source Same Filters (Human)
>
>
>
>
Different Source Same Filters (Non-Human)
sheep
>
>
>
>
Different Source Same Filters (Non-Human)
accordion
>
>
>
>
Different Source Same Filters (Non-Human)If it quacks like a duckhellip
>
>
>
>
Source Filter Theory Applied Alaryngeal Speech
Source-Filter Theory AppliedEsophageal Insufflation Test
Source-Filter Theory AppliedTracheoesophageal (TE) Speech
Source Filter Theory Applied The Talkbox
Source-Filter Theory Applied The Talkbox
httpwwwyoutubecomwatchv=YS3gAVNlceg
Topic 3 A Brief Review of Physical Acoustics
Learning Objectivesbull Outline the physical processes underlying simple harmonic motion using the
mass-spring modelbull Describe the molecular basis of sound wave propagationbull Define the key characteristics of sinusoidal motion including
ndash Amplitude instantaneous peak peak-to-peak root-mean-square (RMS) the decibel scale
ndash Frequencyperiod including units of measurendash Phasendash Wavelength
bull Briefly describe the relation between the sine wave and uniform circular motion
bull Outline the relationship between the frequency and wavelength of a sound wave
Spring Mass Model
bull Mass (inertia)ndash Newtonrsquos first law of motionndash Opposition to
accelerationdecelerationbull Elasticityndash Opposition to displacementndash Rest positionndash Recoil force
bull Complex gt one frequency componentbull Aperiodic Does not repeat itselfbull Frequency components are not systematically
relatedbull May be ndash Continuousndash Transient
Aperiodic sounds Graphic appearance
bull Time domainndash no repeating pattern of pressure change
bull Frequency domainndash the spectrum is dense ndash No ldquopicket fencerdquo
bull Auditory impression sounds lsquonoisyrsquo
Aperiodic sounds Graphic appearance
From Hillenbrand
>
Analysis of complex wavesbull Waves can be summedbull Complex waves are the sum of simple wavesbull Fourier French Mathematician
ndash Any complex waveform may be formed by summing sinusoids of various frequency amplitude and phase
bull Fourier Analysisndash Provides a unique (only one) solution for a given sound signalndash Is reflected in the amplitude and phase spectrum of the signalndash Reveals the building blocks of complex waves which are sinusoids
Learning Objectives
bull Draw and differentiate the waveform and the waveform envelope
bull Draw and differentiate the amplitude spectrum the phase spectrum and the spectrum envelope
bull Differential between short-term spectra and long-term average spectra
The ldquoenveloperdquo of a sound wave
bull Waveform envelopendash imaginary smooth line that follows the peak of the
amplitude of a sound pressure waveformbull Spectrum envelopendash Imaginary smooth line drawn on top of the
amplitude spectrum
Waveform envelope
From Hillenbrand
Waveform envelope
Time
>
Spectrum envelope
Frequency
Ampl
itude
Thought Question
Can an aperiodic and complex periodic sound have identical
spectrum envelopes
Amplitude Spectrum Window Size
bull ldquoshort-termrdquo vs ldquolong-term averagerdquo amplitude spectrum
ldquoInstantaneousrdquo Amplitude Spectra
(Long Term) Average Amplitude Spectrum
Learning Objectivesbull Describe how the amplitude spectrum and the spectrogram are
relatedbull Identify the axis units of the spectrogrambull Provide some advantages of the spectrogram over the
amplitude spectrumbull Distinguish between a wide band and narrow band spectrogram
and outline the different information each providesbull Distinguish between a harmonic and a formant on a
spectrogrambull Be able to draw stylized (highly simplified) spectrograms based
on spectra and spectrum envelopes
The Spectrogram
Rotate90 degrees
F
AF
A
Building a spectrogram
Rotate it so thatThe amplitude isComing out of thepage
F
A This is really narrow because it is a slice in time
F
Time
Building a spectrogram
Dark bands= amplitudePeaks
Time
Freq
uenc
y
Building a spectrogram
Two main types of spectrograms
bull Narrow-band spectrogramsndash Akin to amplitude spectrums ldquolined uprdquondash Frequency resolution is really sharp
bull Wide-band spectrogramsndash Akin to spectrum envelopes ldquolined uprdquondash Frequency resolution not so sharp
Highlights harmonic structure
Highlights spectrum envelope
Wide vs Narrow Band Spectrograms
Learning Objectives
bull Define an acoustic filterbull Draw and label a frequency response curvebull Draw and differentiate different types of acoustic
filtersbull Define terms such as cutoff frequency center
frequency roll off rate gain and bandwidthbull Define and draw a basic filter system and relate that
to the source-filter theory of speech production
What is an ldquoAcousticrdquo Filter
bull holds back (attenuates) certain sounds and lets other sounds through - selective
Why might we be interested in filters
bull Human vocal tract acts like a frequency selective acoustic filter
bull Human auditory system behaves as a frequency selective filter
bull helps us understand how speech is produced and perceived
Kinds of frequency selective filters
Low-pass filtersndash Lets low frequencies ldquopass throughrdquo and attenuates high
frequencies
High-pass filtersndash Lets high frequencies ldquopass throughrdquo and attenuates low
frequencies
Band-pass filtersndash Lets a particular frequency range ldquopass throughrdquo and
attenuates other frequencies
Low Pass Filters
Frequencylow high
Gai
n
+
-
High Pass Filters
Frequencylow high
Gai
n
+
-
Band Pass Filter
Frequencylow high
Gai
n
+
-
Frequency Response Curve (FRC)
Frequencylow high
Gai
n
+
-
Center frequency
lower cutofffrequency
upper cutoff frequency
passband
3 dB
Operation of a filter on a signal
NOTE Amplitude spectrum describes a soundFrequency response curve describes a filter
Learning Objectivesbull Define resonance free and forced vibrationbull Describe how the pendulum and spring mass models can
help explain resonancebull Outline how mass and stiffness influences the resonant
frequency of a mass spring systembull Outline how acoustic resonators behave like acoustic filtersbull Calculate resonant frequencies of a uniform tube based on
its physical dimensionsbull Describe how the wavelength of the sound determines the
resonant frequency of tube
Free vibration
bull objects tend to vibrate at a characteristic or resonant frequency (RF)
Forced vibration
bull A vibrating system can force a nearby system into vibration
bull The efficiency with which this is accomplished is related to the similarity in the resonant frequency (RF) of the two systems
Forced vibration
bull If the RF of the two systems are the same the amplitude of forced vibration will be large
bull If the RF of the two systems are quite different the amplitude of forced vibration will be small or nonexistent
Resonance refers to
bull The tendency for an object to vibrate at a particular frequency or frequencies
bull The ability of a vibrating system to force another system into vibration
Back to the mass spring model
bull Vibratory frequency of the mass spring determined byndash Massndash Stiffness of the spring
httpphetcoloradoeduensimulationmass-spring-lab
Acoustic Resonance
bull Ideas from mechanical resonance also applies to acoustic systems
bull Acoustic chambers will transmit sound frequencies with more or less efficiency depending upon the physical characteristics
bull Therefore they act as filters passing through (and even amplifying) some frequencies and attentuating others
Acoustic Resonance
bull And since they act as filters they have most of the same features of a filter even though we might use different names
bull Center frequency is often termed the resonant frequency
bull Frequency response curve often termed the resonance curve
Helmholtz Resonator
Actions of a Helmholtz Resonator
Stephen M Tasko
Other Acoustic Resonators Tube Resonators
bull Uniform tubes Factors that influence resonancendash Lengthndash Cross-sectional area along its lengthndash Whether it is closed at either or both ends
Uniform tube closed at one end
Uniform tube closed at one end
Stephen M Tasko
Uniform tube closed at one end
First resonance or formant
F1 = c4lWhere
c=speed of sound (35000 cmsec)l = length of the tube
males ~ 175 cmfemales ~ 14 cm
Higher resonantformant frequencies are odd multiples of F1
For examplebull F1 = (c4l )1
bull F2 = (c4l )3
bull F3 = (c4l )5
Comparing Helmholtz and tube resonators
Resonator Features
Sharply tuned Broadly tuned
Resonator Features
An example of the resonance characteristics of the human vocal tract
Frequency
Gain
SPPA 4030 Speech Science
Topic 1 The Speech Chain
The Speech Chain (Denes amp Pinson 1993)
What information is embedded in the speech signal
Branches of science employed to understand speech communication
Physical Quantities Review An Independent Learning Activity
Assignment 1
Topic 2 The Source-Filter Theory of Speech Production An Intr
Producing Speech
Source-Filter Theory of Speech Production
Vocal tract is a tube that can vary its shape
Source Filter Theory
Same Source Different Filter
Different Source Same Filters
Different Source Same Filters (Human)
Different Source Same Filters (Human) (2)
Different Source Same Filters (Human) (3)
Different Source Same Filters (Human) (4)
Different Source Same Filters (Non-Human)
Different Source Same Filters (Non-Human) (2)
Different Source Same Filters (Non-Human) If it quacks like a
Source Filter Theory Applied Alaryngeal Speech
Source-Filter Theory Applied Esophageal Insufflation Test
Source-Filter Theory Applied Tracheoesophageal (TE) Speech
Source Filter Theory Applied The Talkbox
Source-Filter Theory Applied The Talkbox
Topic 3 A Brief Review of Physical Acoustics
Spring Mass Model
What is sound
Sound-conducting media
Model of air molecule vibration (Time 1)
Model of air molecule vibration (Time 2)
Model of air molecule vibration (Time 3)
Model of air molecule vibration (Time 4)
Model of air molecule vibration (Time 5)
Model of air molecule vibration
Wave action of molecular motion
Amplitude waveform
Amplitude waveform (2)
Where is pressure in this model
Pressure waveform
Measuring Sound
Measuring Sound Signal Amplitude
Measuring Sound Signal Amplitude (2)
What units do we use to measure signal amplitude
Brief Review The decibel scale
Absolute vs relative measurement
Typical reference values
Howeverhellip
Linear vs logarithmic
Linear vs logarithmic (2)
Logarithmic Scale
Logarithmic Scale (2)
Combining the idea of logarithmic and relativehellip
Intensity vs Pressure
Extending the formula to pressure
Measuring Sound Frequencyperiod
Measuring Sound Frequencyperiod (2)
Phase Uniform Circular Motion
Initiating a sound waves that differ only in phase
Spatial variation in pressure wave
Spatial variation in pressure wave
Spatial variation in pressure wave (2)
Relation between frequency and wavelength
Learning Objectives
Graphic representation of sound
Same sound different graphs
Classification of sounds
Simple periodic sound
Simple periodic sound Graphic appearance
Complex periodic sounds
Complex periodic sounds Graphic appearance
Complex periodic sounds Graphic appearance (2)
Glottal Source
Amplitude vs Phase Spectrum
Amplitude vs Phase Spectrum (2)
(Complex) Aperiodic sounds
Aperiodic sounds Graphic appearance
Aperiodic sounds Graphic appearance (2)
Analysis of complex waves
Learning Objectives (2)
The ldquoenveloperdquo of a sound wave
Waveform envelope
Waveform envelope (2)
Spectrum envelope
Thought Question
Amplitude Spectrum Window Size
ldquoInstantaneousrdquo Amplitude Spectra
(Long Term) Average Amplitude Spectrum
Slide 90
Learning Objectives (3)
The Spectrogram
Building a spectrogram
Building a spectrogram
Building a spectrogram (2)
Two main types of spectrograms
Wide vs Narrow Band Spectrograms
Learning Objectives (4)
What is an ldquoAcousticrdquo Filter
Why might we be interested in filters
Kinds of frequency selective filters
Low Pass Filters
High Pass Filters
Band Pass Filter
Frequency Response Curve (FRC)
Operation of a filter on a signal
Learning Objectives (5)
Free vibration
Forced vibration
Forced vibration (2)
Resonance refers to
Back to the mass spring model
Acoustic Resonance
Acoustic Resonance (2)
Helmholtz Resonator
Actions of a Helmholtz Resonator
Other Acoustic Resonators Tube Resonators
Uniform tube closed at one end
Uniform tube closed at one end (2)
Uniform tube closed at one end
Comparing Helmholtz and tube resonators
Slide 122
Slide 123
Different Source Same Filters
White Noise
>
>
>
>
Different Source Same Filters (Human)
burp
>
>
>
>
Different Source Same Filters (Human)
snore
>
>
>
>
Different Source Same Filters (Human)
Lip buzz
>
>
>
>
Different Source Same Filters (Human)
>
>
>
>
Different Source Same Filters (Non-Human)
sheep
>
>
>
>
Different Source Same Filters (Non-Human)
accordion
>
>
>
>
Different Source Same Filters (Non-Human)If it quacks like a duckhellip
>
>
>
>
Source Filter Theory Applied Alaryngeal Speech
Source-Filter Theory AppliedEsophageal Insufflation Test
Source-Filter Theory AppliedTracheoesophageal (TE) Speech
Source Filter Theory Applied The Talkbox
Source-Filter Theory Applied The Talkbox
httpwwwyoutubecomwatchv=YS3gAVNlceg
Topic 3 A Brief Review of Physical Acoustics
Learning Objectivesbull Outline the physical processes underlying simple harmonic motion using the
mass-spring modelbull Describe the molecular basis of sound wave propagationbull Define the key characteristics of sinusoidal motion including
ndash Amplitude instantaneous peak peak-to-peak root-mean-square (RMS) the decibel scale
ndash Frequencyperiod including units of measurendash Phasendash Wavelength
bull Briefly describe the relation between the sine wave and uniform circular motion
bull Outline the relationship between the frequency and wavelength of a sound wave
Spring Mass Model
bull Mass (inertia)ndash Newtonrsquos first law of motionndash Opposition to
accelerationdecelerationbull Elasticityndash Opposition to displacementndash Rest positionndash Recoil force
bull Complex gt one frequency componentbull Aperiodic Does not repeat itselfbull Frequency components are not systematically
relatedbull May be ndash Continuousndash Transient
Aperiodic sounds Graphic appearance
bull Time domainndash no repeating pattern of pressure change
bull Frequency domainndash the spectrum is dense ndash No ldquopicket fencerdquo
bull Auditory impression sounds lsquonoisyrsquo
Aperiodic sounds Graphic appearance
From Hillenbrand
>
Analysis of complex wavesbull Waves can be summedbull Complex waves are the sum of simple wavesbull Fourier French Mathematician
ndash Any complex waveform may be formed by summing sinusoids of various frequency amplitude and phase
bull Fourier Analysisndash Provides a unique (only one) solution for a given sound signalndash Is reflected in the amplitude and phase spectrum of the signalndash Reveals the building blocks of complex waves which are sinusoids
Learning Objectives
bull Draw and differentiate the waveform and the waveform envelope
bull Draw and differentiate the amplitude spectrum the phase spectrum and the spectrum envelope
bull Differential between short-term spectra and long-term average spectra
The ldquoenveloperdquo of a sound wave
bull Waveform envelopendash imaginary smooth line that follows the peak of the
amplitude of a sound pressure waveformbull Spectrum envelopendash Imaginary smooth line drawn on top of the
amplitude spectrum
Waveform envelope
From Hillenbrand
Waveform envelope
Time
>
Spectrum envelope
Frequency
Ampl
itude
Thought Question
Can an aperiodic and complex periodic sound have identical
spectrum envelopes
Amplitude Spectrum Window Size
bull ldquoshort-termrdquo vs ldquolong-term averagerdquo amplitude spectrum
ldquoInstantaneousrdquo Amplitude Spectra
(Long Term) Average Amplitude Spectrum
Learning Objectivesbull Describe how the amplitude spectrum and the spectrogram are
relatedbull Identify the axis units of the spectrogrambull Provide some advantages of the spectrogram over the
amplitude spectrumbull Distinguish between a wide band and narrow band spectrogram
and outline the different information each providesbull Distinguish between a harmonic and a formant on a
spectrogrambull Be able to draw stylized (highly simplified) spectrograms based
on spectra and spectrum envelopes
The Spectrogram
Rotate90 degrees
F
AF
A
Building a spectrogram
Rotate it so thatThe amplitude isComing out of thepage
F
A This is really narrow because it is a slice in time
F
Time
Building a spectrogram
Dark bands= amplitudePeaks
Time
Freq
uenc
y
Building a spectrogram
Two main types of spectrograms
bull Narrow-band spectrogramsndash Akin to amplitude spectrums ldquolined uprdquondash Frequency resolution is really sharp
bull Wide-band spectrogramsndash Akin to spectrum envelopes ldquolined uprdquondash Frequency resolution not so sharp
Highlights harmonic structure
Highlights spectrum envelope
Wide vs Narrow Band Spectrograms
Learning Objectives
bull Define an acoustic filterbull Draw and label a frequency response curvebull Draw and differentiate different types of acoustic
filtersbull Define terms such as cutoff frequency center
frequency roll off rate gain and bandwidthbull Define and draw a basic filter system and relate that
to the source-filter theory of speech production
What is an ldquoAcousticrdquo Filter
bull holds back (attenuates) certain sounds and lets other sounds through - selective
Why might we be interested in filters
bull Human vocal tract acts like a frequency selective acoustic filter
bull Human auditory system behaves as a frequency selective filter
bull helps us understand how speech is produced and perceived
Kinds of frequency selective filters
Low-pass filtersndash Lets low frequencies ldquopass throughrdquo and attenuates high
frequencies
High-pass filtersndash Lets high frequencies ldquopass throughrdquo and attenuates low
frequencies
Band-pass filtersndash Lets a particular frequency range ldquopass throughrdquo and
attenuates other frequencies
Low Pass Filters
Frequencylow high
Gai
n
+
-
High Pass Filters
Frequencylow high
Gai
n
+
-
Band Pass Filter
Frequencylow high
Gai
n
+
-
Frequency Response Curve (FRC)
Frequencylow high
Gai
n
+
-
Center frequency
lower cutofffrequency
upper cutoff frequency
passband
3 dB
Operation of a filter on a signal
NOTE Amplitude spectrum describes a soundFrequency response curve describes a filter
Learning Objectivesbull Define resonance free and forced vibrationbull Describe how the pendulum and spring mass models can
help explain resonancebull Outline how mass and stiffness influences the resonant
frequency of a mass spring systembull Outline how acoustic resonators behave like acoustic filtersbull Calculate resonant frequencies of a uniform tube based on
its physical dimensionsbull Describe how the wavelength of the sound determines the
resonant frequency of tube
Free vibration
bull objects tend to vibrate at a characteristic or resonant frequency (RF)
Forced vibration
bull A vibrating system can force a nearby system into vibration
bull The efficiency with which this is accomplished is related to the similarity in the resonant frequency (RF) of the two systems
Forced vibration
bull If the RF of the two systems are the same the amplitude of forced vibration will be large
bull If the RF of the two systems are quite different the amplitude of forced vibration will be small or nonexistent
Resonance refers to
bull The tendency for an object to vibrate at a particular frequency or frequencies
bull The ability of a vibrating system to force another system into vibration
Back to the mass spring model
bull Vibratory frequency of the mass spring determined byndash Massndash Stiffness of the spring
httpphetcoloradoeduensimulationmass-spring-lab
Acoustic Resonance
bull Ideas from mechanical resonance also applies to acoustic systems
bull Acoustic chambers will transmit sound frequencies with more or less efficiency depending upon the physical characteristics
bull Therefore they act as filters passing through (and even amplifying) some frequencies and attentuating others
Acoustic Resonance
bull And since they act as filters they have most of the same features of a filter even though we might use different names
bull Center frequency is often termed the resonant frequency
bull Frequency response curve often termed the resonance curve
Helmholtz Resonator
Actions of a Helmholtz Resonator
Stephen M Tasko
Other Acoustic Resonators Tube Resonators
bull Uniform tubes Factors that influence resonancendash Lengthndash Cross-sectional area along its lengthndash Whether it is closed at either or both ends
Uniform tube closed at one end
Uniform tube closed at one end
Stephen M Tasko
Uniform tube closed at one end
First resonance or formant
F1 = c4lWhere
c=speed of sound (35000 cmsec)l = length of the tube
males ~ 175 cmfemales ~ 14 cm
Higher resonantformant frequencies are odd multiples of F1
For examplebull F1 = (c4l )1
bull F2 = (c4l )3
bull F3 = (c4l )5
Comparing Helmholtz and tube resonators
Resonator Features
Sharply tuned Broadly tuned
Resonator Features
An example of the resonance characteristics of the human vocal tract
Frequency
Gain
SPPA 4030 Speech Science
Topic 1 The Speech Chain
The Speech Chain (Denes amp Pinson 1993)
What information is embedded in the speech signal
Branches of science employed to understand speech communication
Physical Quantities Review An Independent Learning Activity
Assignment 1
Topic 2 The Source-Filter Theory of Speech Production An Intr
Producing Speech
Source-Filter Theory of Speech Production
Vocal tract is a tube that can vary its shape
Source Filter Theory
Same Source Different Filter
Different Source Same Filters
Different Source Same Filters (Human)
Different Source Same Filters (Human) (2)
Different Source Same Filters (Human) (3)
Different Source Same Filters (Human) (4)
Different Source Same Filters (Non-Human)
Different Source Same Filters (Non-Human) (2)
Different Source Same Filters (Non-Human) If it quacks like a
Source Filter Theory Applied Alaryngeal Speech
Source-Filter Theory Applied Esophageal Insufflation Test
Source-Filter Theory Applied Tracheoesophageal (TE) Speech
Source Filter Theory Applied The Talkbox
Source-Filter Theory Applied The Talkbox
Topic 3 A Brief Review of Physical Acoustics
Spring Mass Model
What is sound
Sound-conducting media
Model of air molecule vibration (Time 1)
Model of air molecule vibration (Time 2)
Model of air molecule vibration (Time 3)
Model of air molecule vibration (Time 4)
Model of air molecule vibration (Time 5)
Model of air molecule vibration
Wave action of molecular motion
Amplitude waveform
Amplitude waveform (2)
Where is pressure in this model
Pressure waveform
Measuring Sound
Measuring Sound Signal Amplitude
Measuring Sound Signal Amplitude (2)
What units do we use to measure signal amplitude
Brief Review The decibel scale
Absolute vs relative measurement
Typical reference values
Howeverhellip
Linear vs logarithmic
Linear vs logarithmic (2)
Logarithmic Scale
Logarithmic Scale (2)
Combining the idea of logarithmic and relativehellip
Intensity vs Pressure
Extending the formula to pressure
Measuring Sound Frequencyperiod
Measuring Sound Frequencyperiod (2)
Phase Uniform Circular Motion
Initiating a sound waves that differ only in phase
Spatial variation in pressure wave
Spatial variation in pressure wave
Spatial variation in pressure wave (2)
Relation between frequency and wavelength
Learning Objectives
Graphic representation of sound
Same sound different graphs
Classification of sounds
Simple periodic sound
Simple periodic sound Graphic appearance
Complex periodic sounds
Complex periodic sounds Graphic appearance
Complex periodic sounds Graphic appearance (2)
Glottal Source
Amplitude vs Phase Spectrum
Amplitude vs Phase Spectrum (2)
(Complex) Aperiodic sounds
Aperiodic sounds Graphic appearance
Aperiodic sounds Graphic appearance (2)
Analysis of complex waves
Learning Objectives (2)
The ldquoenveloperdquo of a sound wave
Waveform envelope
Waveform envelope (2)
Spectrum envelope
Thought Question
Amplitude Spectrum Window Size
ldquoInstantaneousrdquo Amplitude Spectra
(Long Term) Average Amplitude Spectrum
Slide 90
Learning Objectives (3)
The Spectrogram
Building a spectrogram
Building a spectrogram
Building a spectrogram (2)
Two main types of spectrograms
Wide vs Narrow Band Spectrograms
Learning Objectives (4)
What is an ldquoAcousticrdquo Filter
Why might we be interested in filters
Kinds of frequency selective filters
Low Pass Filters
High Pass Filters
Band Pass Filter
Frequency Response Curve (FRC)
Operation of a filter on a signal
Learning Objectives (5)
Free vibration
Forced vibration
Forced vibration (2)
Resonance refers to
Back to the mass spring model
Acoustic Resonance
Acoustic Resonance (2)
Helmholtz Resonator
Actions of a Helmholtz Resonator
Other Acoustic Resonators Tube Resonators
Uniform tube closed at one end
Uniform tube closed at one end (2)
Uniform tube closed at one end
Comparing Helmholtz and tube resonators
Slide 122
Slide 123
Different Source Same Filters (Human)
burp
>
>
>
>
Different Source Same Filters (Human)
snore
>
>
>
>
Different Source Same Filters (Human)
Lip buzz
>
>
>
>
Different Source Same Filters (Human)
>
>
>
>
Different Source Same Filters (Non-Human)
sheep
>
>
>
>
Different Source Same Filters (Non-Human)
accordion
>
>
>
>
Different Source Same Filters (Non-Human)If it quacks like a duckhellip
>
>
>
>
Source Filter Theory Applied Alaryngeal Speech
Source-Filter Theory AppliedEsophageal Insufflation Test
Source-Filter Theory AppliedTracheoesophageal (TE) Speech
Source Filter Theory Applied The Talkbox
Source-Filter Theory Applied The Talkbox
httpwwwyoutubecomwatchv=YS3gAVNlceg
Topic 3 A Brief Review of Physical Acoustics
Learning Objectivesbull Outline the physical processes underlying simple harmonic motion using the
mass-spring modelbull Describe the molecular basis of sound wave propagationbull Define the key characteristics of sinusoidal motion including
ndash Amplitude instantaneous peak peak-to-peak root-mean-square (RMS) the decibel scale
ndash Frequencyperiod including units of measurendash Phasendash Wavelength
bull Briefly describe the relation between the sine wave and uniform circular motion
bull Outline the relationship between the frequency and wavelength of a sound wave
Spring Mass Model
bull Mass (inertia)ndash Newtonrsquos first law of motionndash Opposition to
accelerationdecelerationbull Elasticityndash Opposition to displacementndash Rest positionndash Recoil force
bull Complex gt one frequency componentbull Aperiodic Does not repeat itselfbull Frequency components are not systematically
relatedbull May be ndash Continuousndash Transient
Aperiodic sounds Graphic appearance
bull Time domainndash no repeating pattern of pressure change
bull Frequency domainndash the spectrum is dense ndash No ldquopicket fencerdquo
bull Auditory impression sounds lsquonoisyrsquo
Aperiodic sounds Graphic appearance
From Hillenbrand
>
Analysis of complex wavesbull Waves can be summedbull Complex waves are the sum of simple wavesbull Fourier French Mathematician
ndash Any complex waveform may be formed by summing sinusoids of various frequency amplitude and phase
bull Fourier Analysisndash Provides a unique (only one) solution for a given sound signalndash Is reflected in the amplitude and phase spectrum of the signalndash Reveals the building blocks of complex waves which are sinusoids
Learning Objectives
bull Draw and differentiate the waveform and the waveform envelope
bull Draw and differentiate the amplitude spectrum the phase spectrum and the spectrum envelope
bull Differential between short-term spectra and long-term average spectra
The ldquoenveloperdquo of a sound wave
bull Waveform envelopendash imaginary smooth line that follows the peak of the
amplitude of a sound pressure waveformbull Spectrum envelopendash Imaginary smooth line drawn on top of the
amplitude spectrum
Waveform envelope
From Hillenbrand
Waveform envelope
Time
>
Spectrum envelope
Frequency
Ampl
itude
Thought Question
Can an aperiodic and complex periodic sound have identical
spectrum envelopes
Amplitude Spectrum Window Size
bull ldquoshort-termrdquo vs ldquolong-term averagerdquo amplitude spectrum
ldquoInstantaneousrdquo Amplitude Spectra
(Long Term) Average Amplitude Spectrum
Learning Objectivesbull Describe how the amplitude spectrum and the spectrogram are
relatedbull Identify the axis units of the spectrogrambull Provide some advantages of the spectrogram over the
amplitude spectrumbull Distinguish between a wide band and narrow band spectrogram
and outline the different information each providesbull Distinguish between a harmonic and a formant on a
spectrogrambull Be able to draw stylized (highly simplified) spectrograms based
on spectra and spectrum envelopes
The Spectrogram
Rotate90 degrees
F
AF
A
Building a spectrogram
Rotate it so thatThe amplitude isComing out of thepage
F
A This is really narrow because it is a slice in time
F
Time
Building a spectrogram
Dark bands= amplitudePeaks
Time
Freq
uenc
y
Building a spectrogram
Two main types of spectrograms
bull Narrow-band spectrogramsndash Akin to amplitude spectrums ldquolined uprdquondash Frequency resolution is really sharp
bull Wide-band spectrogramsndash Akin to spectrum envelopes ldquolined uprdquondash Frequency resolution not so sharp
Highlights harmonic structure
Highlights spectrum envelope
Wide vs Narrow Band Spectrograms
Learning Objectives
bull Define an acoustic filterbull Draw and label a frequency response curvebull Draw and differentiate different types of acoustic
filtersbull Define terms such as cutoff frequency center
frequency roll off rate gain and bandwidthbull Define and draw a basic filter system and relate that
to the source-filter theory of speech production
What is an ldquoAcousticrdquo Filter
bull holds back (attenuates) certain sounds and lets other sounds through - selective
Why might we be interested in filters
bull Human vocal tract acts like a frequency selective acoustic filter
bull Human auditory system behaves as a frequency selective filter
bull helps us understand how speech is produced and perceived
Kinds of frequency selective filters
Low-pass filtersndash Lets low frequencies ldquopass throughrdquo and attenuates high
frequencies
High-pass filtersndash Lets high frequencies ldquopass throughrdquo and attenuates low
frequencies
Band-pass filtersndash Lets a particular frequency range ldquopass throughrdquo and
attenuates other frequencies
Low Pass Filters
Frequencylow high
Gai
n
+
-
High Pass Filters
Frequencylow high
Gai
n
+
-
Band Pass Filter
Frequencylow high
Gai
n
+
-
Frequency Response Curve (FRC)
Frequencylow high
Gai
n
+
-
Center frequency
lower cutofffrequency
upper cutoff frequency
passband
3 dB
Operation of a filter on a signal
NOTE Amplitude spectrum describes a soundFrequency response curve describes a filter
Learning Objectivesbull Define resonance free and forced vibrationbull Describe how the pendulum and spring mass models can
help explain resonancebull Outline how mass and stiffness influences the resonant
frequency of a mass spring systembull Outline how acoustic resonators behave like acoustic filtersbull Calculate resonant frequencies of a uniform tube based on
its physical dimensionsbull Describe how the wavelength of the sound determines the
resonant frequency of tube
Free vibration
bull objects tend to vibrate at a characteristic or resonant frequency (RF)
Forced vibration
bull A vibrating system can force a nearby system into vibration
bull The efficiency with which this is accomplished is related to the similarity in the resonant frequency (RF) of the two systems
Forced vibration
bull If the RF of the two systems are the same the amplitude of forced vibration will be large
bull If the RF of the two systems are quite different the amplitude of forced vibration will be small or nonexistent
Resonance refers to
bull The tendency for an object to vibrate at a particular frequency or frequencies
bull The ability of a vibrating system to force another system into vibration
Back to the mass spring model
bull Vibratory frequency of the mass spring determined byndash Massndash Stiffness of the spring
httpphetcoloradoeduensimulationmass-spring-lab
Acoustic Resonance
bull Ideas from mechanical resonance also applies to acoustic systems
bull Acoustic chambers will transmit sound frequencies with more or less efficiency depending upon the physical characteristics
bull Therefore they act as filters passing through (and even amplifying) some frequencies and attentuating others
Acoustic Resonance
bull And since they act as filters they have most of the same features of a filter even though we might use different names
bull Center frequency is often termed the resonant frequency
bull Frequency response curve often termed the resonance curve
Helmholtz Resonator
Actions of a Helmholtz Resonator
Stephen M Tasko
Other Acoustic Resonators Tube Resonators
bull Uniform tubes Factors that influence resonancendash Lengthndash Cross-sectional area along its lengthndash Whether it is closed at either or both ends
Uniform tube closed at one end
Uniform tube closed at one end
Stephen M Tasko
Uniform tube closed at one end
First resonance or formant
F1 = c4lWhere
c=speed of sound (35000 cmsec)l = length of the tube
males ~ 175 cmfemales ~ 14 cm
Higher resonantformant frequencies are odd multiples of F1
For examplebull F1 = (c4l )1
bull F2 = (c4l )3
bull F3 = (c4l )5
Comparing Helmholtz and tube resonators
Resonator Features
Sharply tuned Broadly tuned
Resonator Features
An example of the resonance characteristics of the human vocal tract
Frequency
Gain
SPPA 4030 Speech Science
Topic 1 The Speech Chain
The Speech Chain (Denes amp Pinson 1993)
What information is embedded in the speech signal
Branches of science employed to understand speech communication
Physical Quantities Review An Independent Learning Activity
Assignment 1
Topic 2 The Source-Filter Theory of Speech Production An Intr
Producing Speech
Source-Filter Theory of Speech Production
Vocal tract is a tube that can vary its shape
Source Filter Theory
Same Source Different Filter
Different Source Same Filters
Different Source Same Filters (Human)
Different Source Same Filters (Human) (2)
Different Source Same Filters (Human) (3)
Different Source Same Filters (Human) (4)
Different Source Same Filters (Non-Human)
Different Source Same Filters (Non-Human) (2)
Different Source Same Filters (Non-Human) If it quacks like a
Source Filter Theory Applied Alaryngeal Speech
Source-Filter Theory Applied Esophageal Insufflation Test
Source-Filter Theory Applied Tracheoesophageal (TE) Speech
Source Filter Theory Applied The Talkbox
Source-Filter Theory Applied The Talkbox
Topic 3 A Brief Review of Physical Acoustics
Spring Mass Model
What is sound
Sound-conducting media
Model of air molecule vibration (Time 1)
Model of air molecule vibration (Time 2)
Model of air molecule vibration (Time 3)
Model of air molecule vibration (Time 4)
Model of air molecule vibration (Time 5)
Model of air molecule vibration
Wave action of molecular motion
Amplitude waveform
Amplitude waveform (2)
Where is pressure in this model
Pressure waveform
Measuring Sound
Measuring Sound Signal Amplitude
Measuring Sound Signal Amplitude (2)
What units do we use to measure signal amplitude
Brief Review The decibel scale
Absolute vs relative measurement
Typical reference values
Howeverhellip
Linear vs logarithmic
Linear vs logarithmic (2)
Logarithmic Scale
Logarithmic Scale (2)
Combining the idea of logarithmic and relativehellip
Intensity vs Pressure
Extending the formula to pressure
Measuring Sound Frequencyperiod
Measuring Sound Frequencyperiod (2)
Phase Uniform Circular Motion
Initiating a sound waves that differ only in phase
Spatial variation in pressure wave
Spatial variation in pressure wave
Spatial variation in pressure wave (2)
Relation between frequency and wavelength
Learning Objectives
Graphic representation of sound
Same sound different graphs
Classification of sounds
Simple periodic sound
Simple periodic sound Graphic appearance
Complex periodic sounds
Complex periodic sounds Graphic appearance
Complex periodic sounds Graphic appearance (2)
Glottal Source
Amplitude vs Phase Spectrum
Amplitude vs Phase Spectrum (2)
(Complex) Aperiodic sounds
Aperiodic sounds Graphic appearance
Aperiodic sounds Graphic appearance (2)
Analysis of complex waves
Learning Objectives (2)
The ldquoenveloperdquo of a sound wave
Waveform envelope
Waveform envelope (2)
Spectrum envelope
Thought Question
Amplitude Spectrum Window Size
ldquoInstantaneousrdquo Amplitude Spectra
(Long Term) Average Amplitude Spectrum
Slide 90
Learning Objectives (3)
The Spectrogram
Building a spectrogram
Building a spectrogram
Building a spectrogram (2)
Two main types of spectrograms
Wide vs Narrow Band Spectrograms
Learning Objectives (4)
What is an ldquoAcousticrdquo Filter
Why might we be interested in filters
Kinds of frequency selective filters
Low Pass Filters
High Pass Filters
Band Pass Filter
Frequency Response Curve (FRC)
Operation of a filter on a signal
Learning Objectives (5)
Free vibration
Forced vibration
Forced vibration (2)
Resonance refers to
Back to the mass spring model
Acoustic Resonance
Acoustic Resonance (2)
Helmholtz Resonator
Actions of a Helmholtz Resonator
Other Acoustic Resonators Tube Resonators
Uniform tube closed at one end
Uniform tube closed at one end (2)
Uniform tube closed at one end
Comparing Helmholtz and tube resonators
Slide 122
Slide 123
Different Source Same Filters (Human)
snore
>
>
>
>
Different Source Same Filters (Human)
Lip buzz
>
>
>
>
Different Source Same Filters (Human)
>
>
>
>
Different Source Same Filters (Non-Human)
sheep
>
>
>
>
Different Source Same Filters (Non-Human)
accordion
>
>
>
>
Different Source Same Filters (Non-Human)If it quacks like a duckhellip
>
>
>
>
Source Filter Theory Applied Alaryngeal Speech
Source-Filter Theory AppliedEsophageal Insufflation Test
Source-Filter Theory AppliedTracheoesophageal (TE) Speech
Source Filter Theory Applied The Talkbox
Source-Filter Theory Applied The Talkbox
httpwwwyoutubecomwatchv=YS3gAVNlceg
Topic 3 A Brief Review of Physical Acoustics
Learning Objectivesbull Outline the physical processes underlying simple harmonic motion using the
mass-spring modelbull Describe the molecular basis of sound wave propagationbull Define the key characteristics of sinusoidal motion including
ndash Amplitude instantaneous peak peak-to-peak root-mean-square (RMS) the decibel scale
ndash Frequencyperiod including units of measurendash Phasendash Wavelength
bull Briefly describe the relation between the sine wave and uniform circular motion
bull Outline the relationship between the frequency and wavelength of a sound wave
Spring Mass Model
bull Mass (inertia)ndash Newtonrsquos first law of motionndash Opposition to
accelerationdecelerationbull Elasticityndash Opposition to displacementndash Rest positionndash Recoil force
bull Complex gt one frequency componentbull Aperiodic Does not repeat itselfbull Frequency components are not systematically
relatedbull May be ndash Continuousndash Transient
Aperiodic sounds Graphic appearance
bull Time domainndash no repeating pattern of pressure change
bull Frequency domainndash the spectrum is dense ndash No ldquopicket fencerdquo
bull Auditory impression sounds lsquonoisyrsquo
Aperiodic sounds Graphic appearance
From Hillenbrand
>
Analysis of complex wavesbull Waves can be summedbull Complex waves are the sum of simple wavesbull Fourier French Mathematician
ndash Any complex waveform may be formed by summing sinusoids of various frequency amplitude and phase
bull Fourier Analysisndash Provides a unique (only one) solution for a given sound signalndash Is reflected in the amplitude and phase spectrum of the signalndash Reveals the building blocks of complex waves which are sinusoids
Learning Objectives
bull Draw and differentiate the waveform and the waveform envelope
bull Draw and differentiate the amplitude spectrum the phase spectrum and the spectrum envelope
bull Differential between short-term spectra and long-term average spectra
The ldquoenveloperdquo of a sound wave
bull Waveform envelopendash imaginary smooth line that follows the peak of the
amplitude of a sound pressure waveformbull Spectrum envelopendash Imaginary smooth line drawn on top of the
amplitude spectrum
Waveform envelope
From Hillenbrand
Waveform envelope
Time
>
Spectrum envelope
Frequency
Ampl
itude
Thought Question
Can an aperiodic and complex periodic sound have identical
spectrum envelopes
Amplitude Spectrum Window Size
bull ldquoshort-termrdquo vs ldquolong-term averagerdquo amplitude spectrum
ldquoInstantaneousrdquo Amplitude Spectra
(Long Term) Average Amplitude Spectrum
Learning Objectivesbull Describe how the amplitude spectrum and the spectrogram are
relatedbull Identify the axis units of the spectrogrambull Provide some advantages of the spectrogram over the
amplitude spectrumbull Distinguish between a wide band and narrow band spectrogram
and outline the different information each providesbull Distinguish between a harmonic and a formant on a
spectrogrambull Be able to draw stylized (highly simplified) spectrograms based
on spectra and spectrum envelopes
The Spectrogram
Rotate90 degrees
F
AF
A
Building a spectrogram
Rotate it so thatThe amplitude isComing out of thepage
F
A This is really narrow because it is a slice in time
F
Time
Building a spectrogram
Dark bands= amplitudePeaks
Time
Freq
uenc
y
Building a spectrogram
Two main types of spectrograms
bull Narrow-band spectrogramsndash Akin to amplitude spectrums ldquolined uprdquondash Frequency resolution is really sharp
bull Wide-band spectrogramsndash Akin to spectrum envelopes ldquolined uprdquondash Frequency resolution not so sharp
Highlights harmonic structure
Highlights spectrum envelope
Wide vs Narrow Band Spectrograms
Learning Objectives
bull Define an acoustic filterbull Draw and label a frequency response curvebull Draw and differentiate different types of acoustic
filtersbull Define terms such as cutoff frequency center
frequency roll off rate gain and bandwidthbull Define and draw a basic filter system and relate that
to the source-filter theory of speech production
What is an ldquoAcousticrdquo Filter
bull holds back (attenuates) certain sounds and lets other sounds through - selective
Why might we be interested in filters
bull Human vocal tract acts like a frequency selective acoustic filter
bull Human auditory system behaves as a frequency selective filter
bull helps us understand how speech is produced and perceived
Kinds of frequency selective filters
Low-pass filtersndash Lets low frequencies ldquopass throughrdquo and attenuates high
frequencies
High-pass filtersndash Lets high frequencies ldquopass throughrdquo and attenuates low
frequencies
Band-pass filtersndash Lets a particular frequency range ldquopass throughrdquo and
attenuates other frequencies
Low Pass Filters
Frequencylow high
Gai
n
+
-
High Pass Filters
Frequencylow high
Gai
n
+
-
Band Pass Filter
Frequencylow high
Gai
n
+
-
Frequency Response Curve (FRC)
Frequencylow high
Gai
n
+
-
Center frequency
lower cutofffrequency
upper cutoff frequency
passband
3 dB
Operation of a filter on a signal
NOTE Amplitude spectrum describes a soundFrequency response curve describes a filter
Learning Objectivesbull Define resonance free and forced vibrationbull Describe how the pendulum and spring mass models can
help explain resonancebull Outline how mass and stiffness influences the resonant
frequency of a mass spring systembull Outline how acoustic resonators behave like acoustic filtersbull Calculate resonant frequencies of a uniform tube based on
its physical dimensionsbull Describe how the wavelength of the sound determines the
resonant frequency of tube
Free vibration
bull objects tend to vibrate at a characteristic or resonant frequency (RF)
Forced vibration
bull A vibrating system can force a nearby system into vibration
bull The efficiency with which this is accomplished is related to the similarity in the resonant frequency (RF) of the two systems
Forced vibration
bull If the RF of the two systems are the same the amplitude of forced vibration will be large
bull If the RF of the two systems are quite different the amplitude of forced vibration will be small or nonexistent
Resonance refers to
bull The tendency for an object to vibrate at a particular frequency or frequencies
bull The ability of a vibrating system to force another system into vibration
Back to the mass spring model
bull Vibratory frequency of the mass spring determined byndash Massndash Stiffness of the spring
httpphetcoloradoeduensimulationmass-spring-lab
Acoustic Resonance
bull Ideas from mechanical resonance also applies to acoustic systems
bull Acoustic chambers will transmit sound frequencies with more or less efficiency depending upon the physical characteristics
bull Therefore they act as filters passing through (and even amplifying) some frequencies and attentuating others
Acoustic Resonance
bull And since they act as filters they have most of the same features of a filter even though we might use different names
bull Center frequency is often termed the resonant frequency
bull Frequency response curve often termed the resonance curve
Helmholtz Resonator
Actions of a Helmholtz Resonator
Stephen M Tasko
Other Acoustic Resonators Tube Resonators
bull Uniform tubes Factors that influence resonancendash Lengthndash Cross-sectional area along its lengthndash Whether it is closed at either or both ends
Uniform tube closed at one end
Uniform tube closed at one end
Stephen M Tasko
Uniform tube closed at one end
First resonance or formant
F1 = c4lWhere
c=speed of sound (35000 cmsec)l = length of the tube
males ~ 175 cmfemales ~ 14 cm
Higher resonantformant frequencies are odd multiples of F1
For examplebull F1 = (c4l )1
bull F2 = (c4l )3
bull F3 = (c4l )5
Comparing Helmholtz and tube resonators
Resonator Features
Sharply tuned Broadly tuned
Resonator Features
An example of the resonance characteristics of the human vocal tract
Frequency
Gain
SPPA 4030 Speech Science
Topic 1 The Speech Chain
The Speech Chain (Denes amp Pinson 1993)
What information is embedded in the speech signal
Branches of science employed to understand speech communication
Physical Quantities Review An Independent Learning Activity
Assignment 1
Topic 2 The Source-Filter Theory of Speech Production An Intr
Producing Speech
Source-Filter Theory of Speech Production
Vocal tract is a tube that can vary its shape
Source Filter Theory
Same Source Different Filter
Different Source Same Filters
Different Source Same Filters (Human)
Different Source Same Filters (Human) (2)
Different Source Same Filters (Human) (3)
Different Source Same Filters (Human) (4)
Different Source Same Filters (Non-Human)
Different Source Same Filters (Non-Human) (2)
Different Source Same Filters (Non-Human) If it quacks like a
Source Filter Theory Applied Alaryngeal Speech
Source-Filter Theory Applied Esophageal Insufflation Test
Source-Filter Theory Applied Tracheoesophageal (TE) Speech
Source Filter Theory Applied The Talkbox
Source-Filter Theory Applied The Talkbox
Topic 3 A Brief Review of Physical Acoustics
Spring Mass Model
What is sound
Sound-conducting media
Model of air molecule vibration (Time 1)
Model of air molecule vibration (Time 2)
Model of air molecule vibration (Time 3)
Model of air molecule vibration (Time 4)
Model of air molecule vibration (Time 5)
Model of air molecule vibration
Wave action of molecular motion
Amplitude waveform
Amplitude waveform (2)
Where is pressure in this model
Pressure waveform
Measuring Sound
Measuring Sound Signal Amplitude
Measuring Sound Signal Amplitude (2)
What units do we use to measure signal amplitude
Brief Review The decibel scale
Absolute vs relative measurement
Typical reference values
Howeverhellip
Linear vs logarithmic
Linear vs logarithmic (2)
Logarithmic Scale
Logarithmic Scale (2)
Combining the idea of logarithmic and relativehellip
Intensity vs Pressure
Extending the formula to pressure
Measuring Sound Frequencyperiod
Measuring Sound Frequencyperiod (2)
Phase Uniform Circular Motion
Initiating a sound waves that differ only in phase
Spatial variation in pressure wave
Spatial variation in pressure wave
Spatial variation in pressure wave (2)
Relation between frequency and wavelength
Learning Objectives
Graphic representation of sound
Same sound different graphs
Classification of sounds
Simple periodic sound
Simple periodic sound Graphic appearance
Complex periodic sounds
Complex periodic sounds Graphic appearance
Complex periodic sounds Graphic appearance (2)
Glottal Source
Amplitude vs Phase Spectrum
Amplitude vs Phase Spectrum (2)
(Complex) Aperiodic sounds
Aperiodic sounds Graphic appearance
Aperiodic sounds Graphic appearance (2)
Analysis of complex waves
Learning Objectives (2)
The ldquoenveloperdquo of a sound wave
Waveform envelope
Waveform envelope (2)
Spectrum envelope
Thought Question
Amplitude Spectrum Window Size
ldquoInstantaneousrdquo Amplitude Spectra
(Long Term) Average Amplitude Spectrum
Slide 90
Learning Objectives (3)
The Spectrogram
Building a spectrogram
Building a spectrogram
Building a spectrogram (2)
Two main types of spectrograms
Wide vs Narrow Band Spectrograms
Learning Objectives (4)
What is an ldquoAcousticrdquo Filter
Why might we be interested in filters
Kinds of frequency selective filters
Low Pass Filters
High Pass Filters
Band Pass Filter
Frequency Response Curve (FRC)
Operation of a filter on a signal
Learning Objectives (5)
Free vibration
Forced vibration
Forced vibration (2)
Resonance refers to
Back to the mass spring model
Acoustic Resonance
Acoustic Resonance (2)
Helmholtz Resonator
Actions of a Helmholtz Resonator
Other Acoustic Resonators Tube Resonators
Uniform tube closed at one end
Uniform tube closed at one end (2)
Uniform tube closed at one end
Comparing Helmholtz and tube resonators
Slide 122
Slide 123
Different Source Same Filters (Human)
Lip buzz
>
>
>
>
Different Source Same Filters (Human)
>
>
>
>
Different Source Same Filters (Non-Human)
sheep
>
>
>
>
Different Source Same Filters (Non-Human)
accordion
>
>
>
>
Different Source Same Filters (Non-Human)If it quacks like a duckhellip
>
>
>
>
Source Filter Theory Applied Alaryngeal Speech
Source-Filter Theory AppliedEsophageal Insufflation Test
Source-Filter Theory AppliedTracheoesophageal (TE) Speech
Source Filter Theory Applied The Talkbox
Source-Filter Theory Applied The Talkbox
httpwwwyoutubecomwatchv=YS3gAVNlceg
Topic 3 A Brief Review of Physical Acoustics
Learning Objectivesbull Outline the physical processes underlying simple harmonic motion using the
mass-spring modelbull Describe the molecular basis of sound wave propagationbull Define the key characteristics of sinusoidal motion including
ndash Amplitude instantaneous peak peak-to-peak root-mean-square (RMS) the decibel scale
ndash Frequencyperiod including units of measurendash Phasendash Wavelength
bull Briefly describe the relation between the sine wave and uniform circular motion
bull Outline the relationship between the frequency and wavelength of a sound wave
Spring Mass Model
bull Mass (inertia)ndash Newtonrsquos first law of motionndash Opposition to
accelerationdecelerationbull Elasticityndash Opposition to displacementndash Rest positionndash Recoil force
bull Complex gt one frequency componentbull Aperiodic Does not repeat itselfbull Frequency components are not systematically
relatedbull May be ndash Continuousndash Transient
Aperiodic sounds Graphic appearance
bull Time domainndash no repeating pattern of pressure change
bull Frequency domainndash the spectrum is dense ndash No ldquopicket fencerdquo
bull Auditory impression sounds lsquonoisyrsquo
Aperiodic sounds Graphic appearance
From Hillenbrand
>
Analysis of complex wavesbull Waves can be summedbull Complex waves are the sum of simple wavesbull Fourier French Mathematician
ndash Any complex waveform may be formed by summing sinusoids of various frequency amplitude and phase
bull Fourier Analysisndash Provides a unique (only one) solution for a given sound signalndash Is reflected in the amplitude and phase spectrum of the signalndash Reveals the building blocks of complex waves which are sinusoids
Learning Objectives
bull Draw and differentiate the waveform and the waveform envelope
bull Draw and differentiate the amplitude spectrum the phase spectrum and the spectrum envelope
bull Differential between short-term spectra and long-term average spectra
The ldquoenveloperdquo of a sound wave
bull Waveform envelopendash imaginary smooth line that follows the peak of the
amplitude of a sound pressure waveformbull Spectrum envelopendash Imaginary smooth line drawn on top of the
amplitude spectrum
Waveform envelope
From Hillenbrand
Waveform envelope
Time
>
Spectrum envelope
Frequency
Ampl
itude
Thought Question
Can an aperiodic and complex periodic sound have identical
spectrum envelopes
Amplitude Spectrum Window Size
bull ldquoshort-termrdquo vs ldquolong-term averagerdquo amplitude spectrum
ldquoInstantaneousrdquo Amplitude Spectra
(Long Term) Average Amplitude Spectrum
Learning Objectivesbull Describe how the amplitude spectrum and the spectrogram are
relatedbull Identify the axis units of the spectrogrambull Provide some advantages of the spectrogram over the
amplitude spectrumbull Distinguish between a wide band and narrow band spectrogram
and outline the different information each providesbull Distinguish between a harmonic and a formant on a
spectrogrambull Be able to draw stylized (highly simplified) spectrograms based
on spectra and spectrum envelopes
The Spectrogram
Rotate90 degrees
F
AF
A
Building a spectrogram
Rotate it so thatThe amplitude isComing out of thepage
F
A This is really narrow because it is a slice in time
F
Time
Building a spectrogram
Dark bands= amplitudePeaks
Time
Freq
uenc
y
Building a spectrogram
Two main types of spectrograms
bull Narrow-band spectrogramsndash Akin to amplitude spectrums ldquolined uprdquondash Frequency resolution is really sharp
bull Wide-band spectrogramsndash Akin to spectrum envelopes ldquolined uprdquondash Frequency resolution not so sharp
Highlights harmonic structure
Highlights spectrum envelope
Wide vs Narrow Band Spectrograms
Learning Objectives
bull Define an acoustic filterbull Draw and label a frequency response curvebull Draw and differentiate different types of acoustic
filtersbull Define terms such as cutoff frequency center
frequency roll off rate gain and bandwidthbull Define and draw a basic filter system and relate that
to the source-filter theory of speech production
What is an ldquoAcousticrdquo Filter
bull holds back (attenuates) certain sounds and lets other sounds through - selective
Why might we be interested in filters
bull Human vocal tract acts like a frequency selective acoustic filter
bull Human auditory system behaves as a frequency selective filter
bull helps us understand how speech is produced and perceived
Kinds of frequency selective filters
Low-pass filtersndash Lets low frequencies ldquopass throughrdquo and attenuates high
frequencies
High-pass filtersndash Lets high frequencies ldquopass throughrdquo and attenuates low
frequencies
Band-pass filtersndash Lets a particular frequency range ldquopass throughrdquo and
attenuates other frequencies
Low Pass Filters
Frequencylow high
Gai
n
+
-
High Pass Filters
Frequencylow high
Gai
n
+
-
Band Pass Filter
Frequencylow high
Gai
n
+
-
Frequency Response Curve (FRC)
Frequencylow high
Gai
n
+
-
Center frequency
lower cutofffrequency
upper cutoff frequency
passband
3 dB
Operation of a filter on a signal
NOTE Amplitude spectrum describes a soundFrequency response curve describes a filter
Learning Objectivesbull Define resonance free and forced vibrationbull Describe how the pendulum and spring mass models can
help explain resonancebull Outline how mass and stiffness influences the resonant
frequency of a mass spring systembull Outline how acoustic resonators behave like acoustic filtersbull Calculate resonant frequencies of a uniform tube based on
its physical dimensionsbull Describe how the wavelength of the sound determines the
resonant frequency of tube
Free vibration
bull objects tend to vibrate at a characteristic or resonant frequency (RF)
Forced vibration
bull A vibrating system can force a nearby system into vibration
bull The efficiency with which this is accomplished is related to the similarity in the resonant frequency (RF) of the two systems
Forced vibration
bull If the RF of the two systems are the same the amplitude of forced vibration will be large
bull If the RF of the two systems are quite different the amplitude of forced vibration will be small or nonexistent
Resonance refers to
bull The tendency for an object to vibrate at a particular frequency or frequencies
bull The ability of a vibrating system to force another system into vibration
Back to the mass spring model
bull Vibratory frequency of the mass spring determined byndash Massndash Stiffness of the spring
httpphetcoloradoeduensimulationmass-spring-lab
Acoustic Resonance
bull Ideas from mechanical resonance also applies to acoustic systems
bull Acoustic chambers will transmit sound frequencies with more or less efficiency depending upon the physical characteristics
bull Therefore they act as filters passing through (and even amplifying) some frequencies and attentuating others
Acoustic Resonance
bull And since they act as filters they have most of the same features of a filter even though we might use different names
bull Center frequency is often termed the resonant frequency
bull Frequency response curve often termed the resonance curve
Helmholtz Resonator
Actions of a Helmholtz Resonator
Stephen M Tasko
Other Acoustic Resonators Tube Resonators
bull Uniform tubes Factors that influence resonancendash Lengthndash Cross-sectional area along its lengthndash Whether it is closed at either or both ends
Uniform tube closed at one end
Uniform tube closed at one end
Stephen M Tasko
Uniform tube closed at one end
First resonance or formant
F1 = c4lWhere
c=speed of sound (35000 cmsec)l = length of the tube
males ~ 175 cmfemales ~ 14 cm
Higher resonantformant frequencies are odd multiples of F1
For examplebull F1 = (c4l )1
bull F2 = (c4l )3
bull F3 = (c4l )5
Comparing Helmholtz and tube resonators
Resonator Features
Sharply tuned Broadly tuned
Resonator Features
An example of the resonance characteristics of the human vocal tract
Frequency
Gain
SPPA 4030 Speech Science
Topic 1 The Speech Chain
The Speech Chain (Denes amp Pinson 1993)
What information is embedded in the speech signal
Branches of science employed to understand speech communication
Physical Quantities Review An Independent Learning Activity
Assignment 1
Topic 2 The Source-Filter Theory of Speech Production An Intr
Producing Speech
Source-Filter Theory of Speech Production
Vocal tract is a tube that can vary its shape
Source Filter Theory
Same Source Different Filter
Different Source Same Filters
Different Source Same Filters (Human)
Different Source Same Filters (Human) (2)
Different Source Same Filters (Human) (3)
Different Source Same Filters (Human) (4)
Different Source Same Filters (Non-Human)
Different Source Same Filters (Non-Human) (2)
Different Source Same Filters (Non-Human) If it quacks like a
Source Filter Theory Applied Alaryngeal Speech
Source-Filter Theory Applied Esophageal Insufflation Test
Source-Filter Theory Applied Tracheoesophageal (TE) Speech
Source Filter Theory Applied The Talkbox
Source-Filter Theory Applied The Talkbox
Topic 3 A Brief Review of Physical Acoustics
Spring Mass Model
What is sound
Sound-conducting media
Model of air molecule vibration (Time 1)
Model of air molecule vibration (Time 2)
Model of air molecule vibration (Time 3)
Model of air molecule vibration (Time 4)
Model of air molecule vibration (Time 5)
Model of air molecule vibration
Wave action of molecular motion
Amplitude waveform
Amplitude waveform (2)
Where is pressure in this model
Pressure waveform
Measuring Sound
Measuring Sound Signal Amplitude
Measuring Sound Signal Amplitude (2)
What units do we use to measure signal amplitude
Brief Review The decibel scale
Absolute vs relative measurement
Typical reference values
Howeverhellip
Linear vs logarithmic
Linear vs logarithmic (2)
Logarithmic Scale
Logarithmic Scale (2)
Combining the idea of logarithmic and relativehellip
Intensity vs Pressure
Extending the formula to pressure
Measuring Sound Frequencyperiod
Measuring Sound Frequencyperiod (2)
Phase Uniform Circular Motion
Initiating a sound waves that differ only in phase
Spatial variation in pressure wave
Spatial variation in pressure wave
Spatial variation in pressure wave (2)
Relation between frequency and wavelength
Learning Objectives
Graphic representation of sound
Same sound different graphs
Classification of sounds
Simple periodic sound
Simple periodic sound Graphic appearance
Complex periodic sounds
Complex periodic sounds Graphic appearance
Complex periodic sounds Graphic appearance (2)
Glottal Source
Amplitude vs Phase Spectrum
Amplitude vs Phase Spectrum (2)
(Complex) Aperiodic sounds
Aperiodic sounds Graphic appearance
Aperiodic sounds Graphic appearance (2)
Analysis of complex waves
Learning Objectives (2)
The ldquoenveloperdquo of a sound wave
Waveform envelope
Waveform envelope (2)
Spectrum envelope
Thought Question
Amplitude Spectrum Window Size
ldquoInstantaneousrdquo Amplitude Spectra
(Long Term) Average Amplitude Spectrum
Slide 90
Learning Objectives (3)
The Spectrogram
Building a spectrogram
Building a spectrogram
Building a spectrogram (2)
Two main types of spectrograms
Wide vs Narrow Band Spectrograms
Learning Objectives (4)
What is an ldquoAcousticrdquo Filter
Why might we be interested in filters
Kinds of frequency selective filters
Low Pass Filters
High Pass Filters
Band Pass Filter
Frequency Response Curve (FRC)
Operation of a filter on a signal
Learning Objectives (5)
Free vibration
Forced vibration
Forced vibration (2)
Resonance refers to
Back to the mass spring model
Acoustic Resonance
Acoustic Resonance (2)
Helmholtz Resonator
Actions of a Helmholtz Resonator
Other Acoustic Resonators Tube Resonators
Uniform tube closed at one end
Uniform tube closed at one end (2)
Uniform tube closed at one end
Comparing Helmholtz and tube resonators
Slide 122
Slide 123
Different Source Same Filters (Human)
>
>
>
>
Different Source Same Filters (Non-Human)
sheep
>
>
>
>
Different Source Same Filters (Non-Human)
accordion
>
>
>
>
Different Source Same Filters (Non-Human)If it quacks like a duckhellip
>
>
>
>
Source Filter Theory Applied Alaryngeal Speech
Source-Filter Theory AppliedEsophageal Insufflation Test
Source-Filter Theory AppliedTracheoesophageal (TE) Speech
Source Filter Theory Applied The Talkbox
Source-Filter Theory Applied The Talkbox
httpwwwyoutubecomwatchv=YS3gAVNlceg
Topic 3 A Brief Review of Physical Acoustics
Learning Objectivesbull Outline the physical processes underlying simple harmonic motion using the
mass-spring modelbull Describe the molecular basis of sound wave propagationbull Define the key characteristics of sinusoidal motion including
ndash Amplitude instantaneous peak peak-to-peak root-mean-square (RMS) the decibel scale
ndash Frequencyperiod including units of measurendash Phasendash Wavelength
bull Briefly describe the relation between the sine wave and uniform circular motion
bull Outline the relationship between the frequency and wavelength of a sound wave
Spring Mass Model
bull Mass (inertia)ndash Newtonrsquos first law of motionndash Opposition to
accelerationdecelerationbull Elasticityndash Opposition to displacementndash Rest positionndash Recoil force
bull Complex gt one frequency componentbull Aperiodic Does not repeat itselfbull Frequency components are not systematically
relatedbull May be ndash Continuousndash Transient
Aperiodic sounds Graphic appearance
bull Time domainndash no repeating pattern of pressure change
bull Frequency domainndash the spectrum is dense ndash No ldquopicket fencerdquo
bull Auditory impression sounds lsquonoisyrsquo
Aperiodic sounds Graphic appearance
From Hillenbrand
>
Analysis of complex wavesbull Waves can be summedbull Complex waves are the sum of simple wavesbull Fourier French Mathematician
ndash Any complex waveform may be formed by summing sinusoids of various frequency amplitude and phase
bull Fourier Analysisndash Provides a unique (only one) solution for a given sound signalndash Is reflected in the amplitude and phase spectrum of the signalndash Reveals the building blocks of complex waves which are sinusoids
Learning Objectives
bull Draw and differentiate the waveform and the waveform envelope
bull Draw and differentiate the amplitude spectrum the phase spectrum and the spectrum envelope
bull Differential between short-term spectra and long-term average spectra
The ldquoenveloperdquo of a sound wave
bull Waveform envelopendash imaginary smooth line that follows the peak of the
amplitude of a sound pressure waveformbull Spectrum envelopendash Imaginary smooth line drawn on top of the
amplitude spectrum
Waveform envelope
From Hillenbrand
Waveform envelope
Time
>
Spectrum envelope
Frequency
Ampl
itude
Thought Question
Can an aperiodic and complex periodic sound have identical
spectrum envelopes
Amplitude Spectrum Window Size
bull ldquoshort-termrdquo vs ldquolong-term averagerdquo amplitude spectrum
ldquoInstantaneousrdquo Amplitude Spectra
(Long Term) Average Amplitude Spectrum
Learning Objectivesbull Describe how the amplitude spectrum and the spectrogram are
relatedbull Identify the axis units of the spectrogrambull Provide some advantages of the spectrogram over the
amplitude spectrumbull Distinguish between a wide band and narrow band spectrogram
and outline the different information each providesbull Distinguish between a harmonic and a formant on a
spectrogrambull Be able to draw stylized (highly simplified) spectrograms based
on spectra and spectrum envelopes
The Spectrogram
Rotate90 degrees
F
AF
A
Building a spectrogram
Rotate it so thatThe amplitude isComing out of thepage
F
A This is really narrow because it is a slice in time
F
Time
Building a spectrogram
Dark bands= amplitudePeaks
Time
Freq
uenc
y
Building a spectrogram
Two main types of spectrograms
bull Narrow-band spectrogramsndash Akin to amplitude spectrums ldquolined uprdquondash Frequency resolution is really sharp
bull Wide-band spectrogramsndash Akin to spectrum envelopes ldquolined uprdquondash Frequency resolution not so sharp
Highlights harmonic structure
Highlights spectrum envelope
Wide vs Narrow Band Spectrograms
Learning Objectives
bull Define an acoustic filterbull Draw and label a frequency response curvebull Draw and differentiate different types of acoustic
filtersbull Define terms such as cutoff frequency center
frequency roll off rate gain and bandwidthbull Define and draw a basic filter system and relate that
to the source-filter theory of speech production
What is an ldquoAcousticrdquo Filter
bull holds back (attenuates) certain sounds and lets other sounds through - selective
Why might we be interested in filters
bull Human vocal tract acts like a frequency selective acoustic filter
bull Human auditory system behaves as a frequency selective filter
bull helps us understand how speech is produced and perceived
Kinds of frequency selective filters
Low-pass filtersndash Lets low frequencies ldquopass throughrdquo and attenuates high
frequencies
High-pass filtersndash Lets high frequencies ldquopass throughrdquo and attenuates low
frequencies
Band-pass filtersndash Lets a particular frequency range ldquopass throughrdquo and
attenuates other frequencies
Low Pass Filters
Frequencylow high
Gai
n
+
-
High Pass Filters
Frequencylow high
Gai
n
+
-
Band Pass Filter
Frequencylow high
Gai
n
+
-
Frequency Response Curve (FRC)
Frequencylow high
Gai
n
+
-
Center frequency
lower cutofffrequency
upper cutoff frequency
passband
3 dB
Operation of a filter on a signal
NOTE Amplitude spectrum describes a soundFrequency response curve describes a filter
Learning Objectivesbull Define resonance free and forced vibrationbull Describe how the pendulum and spring mass models can
help explain resonancebull Outline how mass and stiffness influences the resonant
frequency of a mass spring systembull Outline how acoustic resonators behave like acoustic filtersbull Calculate resonant frequencies of a uniform tube based on
its physical dimensionsbull Describe how the wavelength of the sound determines the
resonant frequency of tube
Free vibration
bull objects tend to vibrate at a characteristic or resonant frequency (RF)
Forced vibration
bull A vibrating system can force a nearby system into vibration
bull The efficiency with which this is accomplished is related to the similarity in the resonant frequency (RF) of the two systems
Forced vibration
bull If the RF of the two systems are the same the amplitude of forced vibration will be large
bull If the RF of the two systems are quite different the amplitude of forced vibration will be small or nonexistent
Resonance refers to
bull The tendency for an object to vibrate at a particular frequency or frequencies
bull The ability of a vibrating system to force another system into vibration
Back to the mass spring model
bull Vibratory frequency of the mass spring determined byndash Massndash Stiffness of the spring
httpphetcoloradoeduensimulationmass-spring-lab
Acoustic Resonance
bull Ideas from mechanical resonance also applies to acoustic systems
bull Acoustic chambers will transmit sound frequencies with more or less efficiency depending upon the physical characteristics
bull Therefore they act as filters passing through (and even amplifying) some frequencies and attentuating others
Acoustic Resonance
bull And since they act as filters they have most of the same features of a filter even though we might use different names
bull Center frequency is often termed the resonant frequency
bull Frequency response curve often termed the resonance curve
Helmholtz Resonator
Actions of a Helmholtz Resonator
Stephen M Tasko
Other Acoustic Resonators Tube Resonators
bull Uniform tubes Factors that influence resonancendash Lengthndash Cross-sectional area along its lengthndash Whether it is closed at either or both ends
Uniform tube closed at one end
Uniform tube closed at one end
Stephen M Tasko
Uniform tube closed at one end
First resonance or formant
F1 = c4lWhere
c=speed of sound (35000 cmsec)l = length of the tube
males ~ 175 cmfemales ~ 14 cm
Higher resonantformant frequencies are odd multiples of F1
For examplebull F1 = (c4l )1
bull F2 = (c4l )3
bull F3 = (c4l )5
Comparing Helmholtz and tube resonators
Resonator Features
Sharply tuned Broadly tuned
Resonator Features
An example of the resonance characteristics of the human vocal tract
Frequency
Gain
SPPA 4030 Speech Science
Topic 1 The Speech Chain
The Speech Chain (Denes amp Pinson 1993)
What information is embedded in the speech signal
Branches of science employed to understand speech communication
Physical Quantities Review An Independent Learning Activity
Assignment 1
Topic 2 The Source-Filter Theory of Speech Production An Intr
Producing Speech
Source-Filter Theory of Speech Production
Vocal tract is a tube that can vary its shape
Source Filter Theory
Same Source Different Filter
Different Source Same Filters
Different Source Same Filters (Human)
Different Source Same Filters (Human) (2)
Different Source Same Filters (Human) (3)
Different Source Same Filters (Human) (4)
Different Source Same Filters (Non-Human)
Different Source Same Filters (Non-Human) (2)
Different Source Same Filters (Non-Human) If it quacks like a
Source Filter Theory Applied Alaryngeal Speech
Source-Filter Theory Applied Esophageal Insufflation Test
Source-Filter Theory Applied Tracheoesophageal (TE) Speech
Source Filter Theory Applied The Talkbox
Source-Filter Theory Applied The Talkbox
Topic 3 A Brief Review of Physical Acoustics
Spring Mass Model
What is sound
Sound-conducting media
Model of air molecule vibration (Time 1)
Model of air molecule vibration (Time 2)
Model of air molecule vibration (Time 3)
Model of air molecule vibration (Time 4)
Model of air molecule vibration (Time 5)
Model of air molecule vibration
Wave action of molecular motion
Amplitude waveform
Amplitude waveform (2)
Where is pressure in this model
Pressure waveform
Measuring Sound
Measuring Sound Signal Amplitude
Measuring Sound Signal Amplitude (2)
What units do we use to measure signal amplitude
Brief Review The decibel scale
Absolute vs relative measurement
Typical reference values
Howeverhellip
Linear vs logarithmic
Linear vs logarithmic (2)
Logarithmic Scale
Logarithmic Scale (2)
Combining the idea of logarithmic and relativehellip
Intensity vs Pressure
Extending the formula to pressure
Measuring Sound Frequencyperiod
Measuring Sound Frequencyperiod (2)
Phase Uniform Circular Motion
Initiating a sound waves that differ only in phase
Spatial variation in pressure wave
Spatial variation in pressure wave
Spatial variation in pressure wave (2)
Relation between frequency and wavelength
Learning Objectives
Graphic representation of sound
Same sound different graphs
Classification of sounds
Simple periodic sound
Simple periodic sound Graphic appearance
Complex periodic sounds
Complex periodic sounds Graphic appearance
Complex periodic sounds Graphic appearance (2)
Glottal Source
Amplitude vs Phase Spectrum
Amplitude vs Phase Spectrum (2)
(Complex) Aperiodic sounds
Aperiodic sounds Graphic appearance
Aperiodic sounds Graphic appearance (2)
Analysis of complex waves
Learning Objectives (2)
The ldquoenveloperdquo of a sound wave
Waveform envelope
Waveform envelope (2)
Spectrum envelope
Thought Question
Amplitude Spectrum Window Size
ldquoInstantaneousrdquo Amplitude Spectra
(Long Term) Average Amplitude Spectrum
Slide 90
Learning Objectives (3)
The Spectrogram
Building a spectrogram
Building a spectrogram
Building a spectrogram (2)
Two main types of spectrograms
Wide vs Narrow Band Spectrograms
Learning Objectives (4)
What is an ldquoAcousticrdquo Filter
Why might we be interested in filters
Kinds of frequency selective filters
Low Pass Filters
High Pass Filters
Band Pass Filter
Frequency Response Curve (FRC)
Operation of a filter on a signal
Learning Objectives (5)
Free vibration
Forced vibration
Forced vibration (2)
Resonance refers to
Back to the mass spring model
Acoustic Resonance
Acoustic Resonance (2)
Helmholtz Resonator
Actions of a Helmholtz Resonator
Other Acoustic Resonators Tube Resonators
Uniform tube closed at one end
Uniform tube closed at one end (2)
Uniform tube closed at one end
Comparing Helmholtz and tube resonators
Slide 122
Slide 123
Different Source Same Filters (Non-Human)
sheep
>
>
>
>
Different Source Same Filters (Non-Human)
accordion
>
>
>
>
Different Source Same Filters (Non-Human)If it quacks like a duckhellip
>
>
>
>
Source Filter Theory Applied Alaryngeal Speech
Source-Filter Theory AppliedEsophageal Insufflation Test
Source-Filter Theory AppliedTracheoesophageal (TE) Speech
Source Filter Theory Applied The Talkbox
Source-Filter Theory Applied The Talkbox
httpwwwyoutubecomwatchv=YS3gAVNlceg
Topic 3 A Brief Review of Physical Acoustics
Learning Objectivesbull Outline the physical processes underlying simple harmonic motion using the
mass-spring modelbull Describe the molecular basis of sound wave propagationbull Define the key characteristics of sinusoidal motion including
ndash Amplitude instantaneous peak peak-to-peak root-mean-square (RMS) the decibel scale
ndash Frequencyperiod including units of measurendash Phasendash Wavelength
bull Briefly describe the relation between the sine wave and uniform circular motion
bull Outline the relationship between the frequency and wavelength of a sound wave
Spring Mass Model
bull Mass (inertia)ndash Newtonrsquos first law of motionndash Opposition to
accelerationdecelerationbull Elasticityndash Opposition to displacementndash Rest positionndash Recoil force
bull Complex gt one frequency componentbull Aperiodic Does not repeat itselfbull Frequency components are not systematically
relatedbull May be ndash Continuousndash Transient
Aperiodic sounds Graphic appearance
bull Time domainndash no repeating pattern of pressure change
bull Frequency domainndash the spectrum is dense ndash No ldquopicket fencerdquo
bull Auditory impression sounds lsquonoisyrsquo
Aperiodic sounds Graphic appearance
From Hillenbrand
>
Analysis of complex wavesbull Waves can be summedbull Complex waves are the sum of simple wavesbull Fourier French Mathematician
ndash Any complex waveform may be formed by summing sinusoids of various frequency amplitude and phase
bull Fourier Analysisndash Provides a unique (only one) solution for a given sound signalndash Is reflected in the amplitude and phase spectrum of the signalndash Reveals the building blocks of complex waves which are sinusoids
Learning Objectives
bull Draw and differentiate the waveform and the waveform envelope
bull Draw and differentiate the amplitude spectrum the phase spectrum and the spectrum envelope
bull Differential between short-term spectra and long-term average spectra
The ldquoenveloperdquo of a sound wave
bull Waveform envelopendash imaginary smooth line that follows the peak of the
amplitude of a sound pressure waveformbull Spectrum envelopendash Imaginary smooth line drawn on top of the
amplitude spectrum
Waveform envelope
From Hillenbrand
Waveform envelope
Time
>
Spectrum envelope
Frequency
Ampl
itude
Thought Question
Can an aperiodic and complex periodic sound have identical
spectrum envelopes
Amplitude Spectrum Window Size
bull ldquoshort-termrdquo vs ldquolong-term averagerdquo amplitude spectrum
ldquoInstantaneousrdquo Amplitude Spectra
(Long Term) Average Amplitude Spectrum
Learning Objectivesbull Describe how the amplitude spectrum and the spectrogram are
relatedbull Identify the axis units of the spectrogrambull Provide some advantages of the spectrogram over the
amplitude spectrumbull Distinguish between a wide band and narrow band spectrogram
and outline the different information each providesbull Distinguish between a harmonic and a formant on a
spectrogrambull Be able to draw stylized (highly simplified) spectrograms based
on spectra and spectrum envelopes
The Spectrogram
Rotate90 degrees
F
AF
A
Building a spectrogram
Rotate it so thatThe amplitude isComing out of thepage
F
A This is really narrow because it is a slice in time
F
Time
Building a spectrogram
Dark bands= amplitudePeaks
Time
Freq
uenc
y
Building a spectrogram
Two main types of spectrograms
bull Narrow-band spectrogramsndash Akin to amplitude spectrums ldquolined uprdquondash Frequency resolution is really sharp
bull Wide-band spectrogramsndash Akin to spectrum envelopes ldquolined uprdquondash Frequency resolution not so sharp
Highlights harmonic structure
Highlights spectrum envelope
Wide vs Narrow Band Spectrograms
Learning Objectives
bull Define an acoustic filterbull Draw and label a frequency response curvebull Draw and differentiate different types of acoustic
filtersbull Define terms such as cutoff frequency center
frequency roll off rate gain and bandwidthbull Define and draw a basic filter system and relate that
to the source-filter theory of speech production
What is an ldquoAcousticrdquo Filter
bull holds back (attenuates) certain sounds and lets other sounds through - selective
Why might we be interested in filters
bull Human vocal tract acts like a frequency selective acoustic filter
bull Human auditory system behaves as a frequency selective filter
bull helps us understand how speech is produced and perceived
Kinds of frequency selective filters
Low-pass filtersndash Lets low frequencies ldquopass throughrdquo and attenuates high
frequencies
High-pass filtersndash Lets high frequencies ldquopass throughrdquo and attenuates low
frequencies
Band-pass filtersndash Lets a particular frequency range ldquopass throughrdquo and
attenuates other frequencies
Low Pass Filters
Frequencylow high
Gai
n
+
-
High Pass Filters
Frequencylow high
Gai
n
+
-
Band Pass Filter
Frequencylow high
Gai
n
+
-
Frequency Response Curve (FRC)
Frequencylow high
Gai
n
+
-
Center frequency
lower cutofffrequency
upper cutoff frequency
passband
3 dB
Operation of a filter on a signal
NOTE Amplitude spectrum describes a soundFrequency response curve describes a filter
Learning Objectivesbull Define resonance free and forced vibrationbull Describe how the pendulum and spring mass models can
help explain resonancebull Outline how mass and stiffness influences the resonant
frequency of a mass spring systembull Outline how acoustic resonators behave like acoustic filtersbull Calculate resonant frequencies of a uniform tube based on
its physical dimensionsbull Describe how the wavelength of the sound determines the
resonant frequency of tube
Free vibration
bull objects tend to vibrate at a characteristic or resonant frequency (RF)
Forced vibration
bull A vibrating system can force a nearby system into vibration
bull The efficiency with which this is accomplished is related to the similarity in the resonant frequency (RF) of the two systems
Forced vibration
bull If the RF of the two systems are the same the amplitude of forced vibration will be large
bull If the RF of the two systems are quite different the amplitude of forced vibration will be small or nonexistent
Resonance refers to
bull The tendency for an object to vibrate at a particular frequency or frequencies
bull The ability of a vibrating system to force another system into vibration
Back to the mass spring model
bull Vibratory frequency of the mass spring determined byndash Massndash Stiffness of the spring
httpphetcoloradoeduensimulationmass-spring-lab
Acoustic Resonance
bull Ideas from mechanical resonance also applies to acoustic systems
bull Acoustic chambers will transmit sound frequencies with more or less efficiency depending upon the physical characteristics
bull Therefore they act as filters passing through (and even amplifying) some frequencies and attentuating others
Acoustic Resonance
bull And since they act as filters they have most of the same features of a filter even though we might use different names
bull Center frequency is often termed the resonant frequency
bull Frequency response curve often termed the resonance curve
Helmholtz Resonator
Actions of a Helmholtz Resonator
Stephen M Tasko
Other Acoustic Resonators Tube Resonators
bull Uniform tubes Factors that influence resonancendash Lengthndash Cross-sectional area along its lengthndash Whether it is closed at either or both ends
Uniform tube closed at one end
Uniform tube closed at one end
Stephen M Tasko
Uniform tube closed at one end
First resonance or formant
F1 = c4lWhere
c=speed of sound (35000 cmsec)l = length of the tube
males ~ 175 cmfemales ~ 14 cm
Higher resonantformant frequencies are odd multiples of F1
For examplebull F1 = (c4l )1
bull F2 = (c4l )3
bull F3 = (c4l )5
Comparing Helmholtz and tube resonators
Resonator Features
Sharply tuned Broadly tuned
Resonator Features
An example of the resonance characteristics of the human vocal tract
Frequency
Gain
SPPA 4030 Speech Science
Topic 1 The Speech Chain
The Speech Chain (Denes amp Pinson 1993)
What information is embedded in the speech signal
Branches of science employed to understand speech communication
Physical Quantities Review An Independent Learning Activity
Assignment 1
Topic 2 The Source-Filter Theory of Speech Production An Intr
Producing Speech
Source-Filter Theory of Speech Production
Vocal tract is a tube that can vary its shape
Source Filter Theory
Same Source Different Filter
Different Source Same Filters
Different Source Same Filters (Human)
Different Source Same Filters (Human) (2)
Different Source Same Filters (Human) (3)
Different Source Same Filters (Human) (4)
Different Source Same Filters (Non-Human)
Different Source Same Filters (Non-Human) (2)
Different Source Same Filters (Non-Human) If it quacks like a
Source Filter Theory Applied Alaryngeal Speech
Source-Filter Theory Applied Esophageal Insufflation Test
Source-Filter Theory Applied Tracheoesophageal (TE) Speech
Source Filter Theory Applied The Talkbox
Source-Filter Theory Applied The Talkbox
Topic 3 A Brief Review of Physical Acoustics
Spring Mass Model
What is sound
Sound-conducting media
Model of air molecule vibration (Time 1)
Model of air molecule vibration (Time 2)
Model of air molecule vibration (Time 3)
Model of air molecule vibration (Time 4)
Model of air molecule vibration (Time 5)
Model of air molecule vibration
Wave action of molecular motion
Amplitude waveform
Amplitude waveform (2)
Where is pressure in this model
Pressure waveform
Measuring Sound
Measuring Sound Signal Amplitude
Measuring Sound Signal Amplitude (2)
What units do we use to measure signal amplitude
Brief Review The decibel scale
Absolute vs relative measurement
Typical reference values
Howeverhellip
Linear vs logarithmic
Linear vs logarithmic (2)
Logarithmic Scale
Logarithmic Scale (2)
Combining the idea of logarithmic and relativehellip
Intensity vs Pressure
Extending the formula to pressure
Measuring Sound Frequencyperiod
Measuring Sound Frequencyperiod (2)
Phase Uniform Circular Motion
Initiating a sound waves that differ only in phase
Spatial variation in pressure wave
Spatial variation in pressure wave
Spatial variation in pressure wave (2)
Relation between frequency and wavelength
Learning Objectives
Graphic representation of sound
Same sound different graphs
Classification of sounds
Simple periodic sound
Simple periodic sound Graphic appearance
Complex periodic sounds
Complex periodic sounds Graphic appearance
Complex periodic sounds Graphic appearance (2)
Glottal Source
Amplitude vs Phase Spectrum
Amplitude vs Phase Spectrum (2)
(Complex) Aperiodic sounds
Aperiodic sounds Graphic appearance
Aperiodic sounds Graphic appearance (2)
Analysis of complex waves
Learning Objectives (2)
The ldquoenveloperdquo of a sound wave
Waveform envelope
Waveform envelope (2)
Spectrum envelope
Thought Question
Amplitude Spectrum Window Size
ldquoInstantaneousrdquo Amplitude Spectra
(Long Term) Average Amplitude Spectrum
Slide 90
Learning Objectives (3)
The Spectrogram
Building a spectrogram
Building a spectrogram
Building a spectrogram (2)
Two main types of spectrograms
Wide vs Narrow Band Spectrograms
Learning Objectives (4)
What is an ldquoAcousticrdquo Filter
Why might we be interested in filters
Kinds of frequency selective filters
Low Pass Filters
High Pass Filters
Band Pass Filter
Frequency Response Curve (FRC)
Operation of a filter on a signal
Learning Objectives (5)
Free vibration
Forced vibration
Forced vibration (2)
Resonance refers to
Back to the mass spring model
Acoustic Resonance
Acoustic Resonance (2)
Helmholtz Resonator
Actions of a Helmholtz Resonator
Other Acoustic Resonators Tube Resonators
Uniform tube closed at one end
Uniform tube closed at one end (2)
Uniform tube closed at one end
Comparing Helmholtz and tube resonators
Slide 122
Slide 123
Different Source Same Filters (Non-Human)
accordion
>
>
>
>
Different Source Same Filters (Non-Human)If it quacks like a duckhellip
>
>
>
>
Source Filter Theory Applied Alaryngeal Speech
Source-Filter Theory AppliedEsophageal Insufflation Test
Source-Filter Theory AppliedTracheoesophageal (TE) Speech
Source Filter Theory Applied The Talkbox
Source-Filter Theory Applied The Talkbox
httpwwwyoutubecomwatchv=YS3gAVNlceg
Topic 3 A Brief Review of Physical Acoustics
Learning Objectivesbull Outline the physical processes underlying simple harmonic motion using the
mass-spring modelbull Describe the molecular basis of sound wave propagationbull Define the key characteristics of sinusoidal motion including
ndash Amplitude instantaneous peak peak-to-peak root-mean-square (RMS) the decibel scale
ndash Frequencyperiod including units of measurendash Phasendash Wavelength
bull Briefly describe the relation between the sine wave and uniform circular motion
bull Outline the relationship between the frequency and wavelength of a sound wave
Spring Mass Model
bull Mass (inertia)ndash Newtonrsquos first law of motionndash Opposition to
accelerationdecelerationbull Elasticityndash Opposition to displacementndash Rest positionndash Recoil force
bull Complex gt one frequency componentbull Aperiodic Does not repeat itselfbull Frequency components are not systematically
relatedbull May be ndash Continuousndash Transient
Aperiodic sounds Graphic appearance
bull Time domainndash no repeating pattern of pressure change
bull Frequency domainndash the spectrum is dense ndash No ldquopicket fencerdquo
bull Auditory impression sounds lsquonoisyrsquo
Aperiodic sounds Graphic appearance
From Hillenbrand
>
Analysis of complex wavesbull Waves can be summedbull Complex waves are the sum of simple wavesbull Fourier French Mathematician
ndash Any complex waveform may be formed by summing sinusoids of various frequency amplitude and phase
bull Fourier Analysisndash Provides a unique (only one) solution for a given sound signalndash Is reflected in the amplitude and phase spectrum of the signalndash Reveals the building blocks of complex waves which are sinusoids
Learning Objectives
bull Draw and differentiate the waveform and the waveform envelope
bull Draw and differentiate the amplitude spectrum the phase spectrum and the spectrum envelope
bull Differential between short-term spectra and long-term average spectra
The ldquoenveloperdquo of a sound wave
bull Waveform envelopendash imaginary smooth line that follows the peak of the
amplitude of a sound pressure waveformbull Spectrum envelopendash Imaginary smooth line drawn on top of the
amplitude spectrum
Waveform envelope
From Hillenbrand
Waveform envelope
Time
>
Spectrum envelope
Frequency
Ampl
itude
Thought Question
Can an aperiodic and complex periodic sound have identical
spectrum envelopes
Amplitude Spectrum Window Size
bull ldquoshort-termrdquo vs ldquolong-term averagerdquo amplitude spectrum
ldquoInstantaneousrdquo Amplitude Spectra
(Long Term) Average Amplitude Spectrum
Learning Objectivesbull Describe how the amplitude spectrum and the spectrogram are
relatedbull Identify the axis units of the spectrogrambull Provide some advantages of the spectrogram over the
amplitude spectrumbull Distinguish between a wide band and narrow band spectrogram
and outline the different information each providesbull Distinguish between a harmonic and a formant on a
spectrogrambull Be able to draw stylized (highly simplified) spectrograms based
on spectra and spectrum envelopes
The Spectrogram
Rotate90 degrees
F
AF
A
Building a spectrogram
Rotate it so thatThe amplitude isComing out of thepage
F
A This is really narrow because it is a slice in time
F
Time
Building a spectrogram
Dark bands= amplitudePeaks
Time
Freq
uenc
y
Building a spectrogram
Two main types of spectrograms
bull Narrow-band spectrogramsndash Akin to amplitude spectrums ldquolined uprdquondash Frequency resolution is really sharp
bull Wide-band spectrogramsndash Akin to spectrum envelopes ldquolined uprdquondash Frequency resolution not so sharp
Highlights harmonic structure
Highlights spectrum envelope
Wide vs Narrow Band Spectrograms
Learning Objectives
bull Define an acoustic filterbull Draw and label a frequency response curvebull Draw and differentiate different types of acoustic
filtersbull Define terms such as cutoff frequency center
frequency roll off rate gain and bandwidthbull Define and draw a basic filter system and relate that
to the source-filter theory of speech production
What is an ldquoAcousticrdquo Filter
bull holds back (attenuates) certain sounds and lets other sounds through - selective
Why might we be interested in filters
bull Human vocal tract acts like a frequency selective acoustic filter
bull Human auditory system behaves as a frequency selective filter
bull helps us understand how speech is produced and perceived
Kinds of frequency selective filters
Low-pass filtersndash Lets low frequencies ldquopass throughrdquo and attenuates high
frequencies
High-pass filtersndash Lets high frequencies ldquopass throughrdquo and attenuates low
frequencies
Band-pass filtersndash Lets a particular frequency range ldquopass throughrdquo and
attenuates other frequencies
Low Pass Filters
Frequencylow high
Gai
n
+
-
High Pass Filters
Frequencylow high
Gai
n
+
-
Band Pass Filter
Frequencylow high
Gai
n
+
-
Frequency Response Curve (FRC)
Frequencylow high
Gai
n
+
-
Center frequency
lower cutofffrequency
upper cutoff frequency
passband
3 dB
Operation of a filter on a signal
NOTE Amplitude spectrum describes a soundFrequency response curve describes a filter
Learning Objectivesbull Define resonance free and forced vibrationbull Describe how the pendulum and spring mass models can
help explain resonancebull Outline how mass and stiffness influences the resonant
frequency of a mass spring systembull Outline how acoustic resonators behave like acoustic filtersbull Calculate resonant frequencies of a uniform tube based on
its physical dimensionsbull Describe how the wavelength of the sound determines the
resonant frequency of tube
Free vibration
bull objects tend to vibrate at a characteristic or resonant frequency (RF)
Forced vibration
bull A vibrating system can force a nearby system into vibration
bull The efficiency with which this is accomplished is related to the similarity in the resonant frequency (RF) of the two systems
Forced vibration
bull If the RF of the two systems are the same the amplitude of forced vibration will be large
bull If the RF of the two systems are quite different the amplitude of forced vibration will be small or nonexistent
Resonance refers to
bull The tendency for an object to vibrate at a particular frequency or frequencies
bull The ability of a vibrating system to force another system into vibration
Back to the mass spring model
bull Vibratory frequency of the mass spring determined byndash Massndash Stiffness of the spring
httpphetcoloradoeduensimulationmass-spring-lab
Acoustic Resonance
bull Ideas from mechanical resonance also applies to acoustic systems
bull Acoustic chambers will transmit sound frequencies with more or less efficiency depending upon the physical characteristics
bull Therefore they act as filters passing through (and even amplifying) some frequencies and attentuating others
Acoustic Resonance
bull And since they act as filters they have most of the same features of a filter even though we might use different names
bull Center frequency is often termed the resonant frequency
bull Frequency response curve often termed the resonance curve
Helmholtz Resonator
Actions of a Helmholtz Resonator
Stephen M Tasko
Other Acoustic Resonators Tube Resonators
bull Uniform tubes Factors that influence resonancendash Lengthndash Cross-sectional area along its lengthndash Whether it is closed at either or both ends
Uniform tube closed at one end
Uniform tube closed at one end
Stephen M Tasko
Uniform tube closed at one end
First resonance or formant
F1 = c4lWhere
c=speed of sound (35000 cmsec)l = length of the tube
males ~ 175 cmfemales ~ 14 cm
Higher resonantformant frequencies are odd multiples of F1
For examplebull F1 = (c4l )1
bull F2 = (c4l )3
bull F3 = (c4l )5
Comparing Helmholtz and tube resonators
Resonator Features
Sharply tuned Broadly tuned
Resonator Features
An example of the resonance characteristics of the human vocal tract
Frequency
Gain
SPPA 4030 Speech Science
Topic 1 The Speech Chain
The Speech Chain (Denes amp Pinson 1993)
What information is embedded in the speech signal
Branches of science employed to understand speech communication
Physical Quantities Review An Independent Learning Activity
Assignment 1
Topic 2 The Source-Filter Theory of Speech Production An Intr
Producing Speech
Source-Filter Theory of Speech Production
Vocal tract is a tube that can vary its shape
Source Filter Theory
Same Source Different Filter
Different Source Same Filters
Different Source Same Filters (Human)
Different Source Same Filters (Human) (2)
Different Source Same Filters (Human) (3)
Different Source Same Filters (Human) (4)
Different Source Same Filters (Non-Human)
Different Source Same Filters (Non-Human) (2)
Different Source Same Filters (Non-Human) If it quacks like a
Source Filter Theory Applied Alaryngeal Speech
Source-Filter Theory Applied Esophageal Insufflation Test
Source-Filter Theory Applied Tracheoesophageal (TE) Speech
Source Filter Theory Applied The Talkbox
Source-Filter Theory Applied The Talkbox
Topic 3 A Brief Review of Physical Acoustics
Spring Mass Model
What is sound
Sound-conducting media
Model of air molecule vibration (Time 1)
Model of air molecule vibration (Time 2)
Model of air molecule vibration (Time 3)
Model of air molecule vibration (Time 4)
Model of air molecule vibration (Time 5)
Model of air molecule vibration
Wave action of molecular motion
Amplitude waveform
Amplitude waveform (2)
Where is pressure in this model
Pressure waveform
Measuring Sound
Measuring Sound Signal Amplitude
Measuring Sound Signal Amplitude (2)
What units do we use to measure signal amplitude
Brief Review The decibel scale
Absolute vs relative measurement
Typical reference values
Howeverhellip
Linear vs logarithmic
Linear vs logarithmic (2)
Logarithmic Scale
Logarithmic Scale (2)
Combining the idea of logarithmic and relativehellip
Intensity vs Pressure
Extending the formula to pressure
Measuring Sound Frequencyperiod
Measuring Sound Frequencyperiod (2)
Phase Uniform Circular Motion
Initiating a sound waves that differ only in phase
Spatial variation in pressure wave
Spatial variation in pressure wave
Spatial variation in pressure wave (2)
Relation between frequency and wavelength
Learning Objectives
Graphic representation of sound
Same sound different graphs
Classification of sounds
Simple periodic sound
Simple periodic sound Graphic appearance
Complex periodic sounds
Complex periodic sounds Graphic appearance
Complex periodic sounds Graphic appearance (2)
Glottal Source
Amplitude vs Phase Spectrum
Amplitude vs Phase Spectrum (2)
(Complex) Aperiodic sounds
Aperiodic sounds Graphic appearance
Aperiodic sounds Graphic appearance (2)
Analysis of complex waves
Learning Objectives (2)
The ldquoenveloperdquo of a sound wave
Waveform envelope
Waveform envelope (2)
Spectrum envelope
Thought Question
Amplitude Spectrum Window Size
ldquoInstantaneousrdquo Amplitude Spectra
(Long Term) Average Amplitude Spectrum
Slide 90
Learning Objectives (3)
The Spectrogram
Building a spectrogram
Building a spectrogram
Building a spectrogram (2)
Two main types of spectrograms
Wide vs Narrow Band Spectrograms
Learning Objectives (4)
What is an ldquoAcousticrdquo Filter
Why might we be interested in filters
Kinds of frequency selective filters
Low Pass Filters
High Pass Filters
Band Pass Filter
Frequency Response Curve (FRC)
Operation of a filter on a signal
Learning Objectives (5)
Free vibration
Forced vibration
Forced vibration (2)
Resonance refers to
Back to the mass spring model
Acoustic Resonance
Acoustic Resonance (2)
Helmholtz Resonator
Actions of a Helmholtz Resonator
Other Acoustic Resonators Tube Resonators
Uniform tube closed at one end
Uniform tube closed at one end (2)
Uniform tube closed at one end
Comparing Helmholtz and tube resonators
Slide 122
Slide 123
Different Source Same Filters (Non-Human)If it quacks like a duckhellip
>
>
>
>
Source Filter Theory Applied Alaryngeal Speech
Source-Filter Theory AppliedEsophageal Insufflation Test
Source-Filter Theory AppliedTracheoesophageal (TE) Speech
Source Filter Theory Applied The Talkbox
Source-Filter Theory Applied The Talkbox
httpwwwyoutubecomwatchv=YS3gAVNlceg
Topic 3 A Brief Review of Physical Acoustics
Learning Objectivesbull Outline the physical processes underlying simple harmonic motion using the
mass-spring modelbull Describe the molecular basis of sound wave propagationbull Define the key characteristics of sinusoidal motion including
ndash Amplitude instantaneous peak peak-to-peak root-mean-square (RMS) the decibel scale
ndash Frequencyperiod including units of measurendash Phasendash Wavelength
bull Briefly describe the relation between the sine wave and uniform circular motion
bull Outline the relationship between the frequency and wavelength of a sound wave
Spring Mass Model
bull Mass (inertia)ndash Newtonrsquos first law of motionndash Opposition to
accelerationdecelerationbull Elasticityndash Opposition to displacementndash Rest positionndash Recoil force
bull Complex gt one frequency componentbull Aperiodic Does not repeat itselfbull Frequency components are not systematically
relatedbull May be ndash Continuousndash Transient
Aperiodic sounds Graphic appearance
bull Time domainndash no repeating pattern of pressure change
bull Frequency domainndash the spectrum is dense ndash No ldquopicket fencerdquo
bull Auditory impression sounds lsquonoisyrsquo
Aperiodic sounds Graphic appearance
From Hillenbrand
>
Analysis of complex wavesbull Waves can be summedbull Complex waves are the sum of simple wavesbull Fourier French Mathematician
ndash Any complex waveform may be formed by summing sinusoids of various frequency amplitude and phase
bull Fourier Analysisndash Provides a unique (only one) solution for a given sound signalndash Is reflected in the amplitude and phase spectrum of the signalndash Reveals the building blocks of complex waves which are sinusoids
Learning Objectives
bull Draw and differentiate the waveform and the waveform envelope
bull Draw and differentiate the amplitude spectrum the phase spectrum and the spectrum envelope
bull Differential between short-term spectra and long-term average spectra
The ldquoenveloperdquo of a sound wave
bull Waveform envelopendash imaginary smooth line that follows the peak of the
amplitude of a sound pressure waveformbull Spectrum envelopendash Imaginary smooth line drawn on top of the
amplitude spectrum
Waveform envelope
From Hillenbrand
Waveform envelope
Time
>
Spectrum envelope
Frequency
Ampl
itude
Thought Question
Can an aperiodic and complex periodic sound have identical
spectrum envelopes
Amplitude Spectrum Window Size
bull ldquoshort-termrdquo vs ldquolong-term averagerdquo amplitude spectrum
ldquoInstantaneousrdquo Amplitude Spectra
(Long Term) Average Amplitude Spectrum
Learning Objectivesbull Describe how the amplitude spectrum and the spectrogram are
relatedbull Identify the axis units of the spectrogrambull Provide some advantages of the spectrogram over the
amplitude spectrumbull Distinguish between a wide band and narrow band spectrogram
and outline the different information each providesbull Distinguish between a harmonic and a formant on a
spectrogrambull Be able to draw stylized (highly simplified) spectrograms based
on spectra and spectrum envelopes
The Spectrogram
Rotate90 degrees
F
AF
A
Building a spectrogram
Rotate it so thatThe amplitude isComing out of thepage
F
A This is really narrow because it is a slice in time
F
Time
Building a spectrogram
Dark bands= amplitudePeaks
Time
Freq
uenc
y
Building a spectrogram
Two main types of spectrograms
bull Narrow-band spectrogramsndash Akin to amplitude spectrums ldquolined uprdquondash Frequency resolution is really sharp
bull Wide-band spectrogramsndash Akin to spectrum envelopes ldquolined uprdquondash Frequency resolution not so sharp
Highlights harmonic structure
Highlights spectrum envelope
Wide vs Narrow Band Spectrograms
Learning Objectives
bull Define an acoustic filterbull Draw and label a frequency response curvebull Draw and differentiate different types of acoustic
filtersbull Define terms such as cutoff frequency center
frequency roll off rate gain and bandwidthbull Define and draw a basic filter system and relate that
to the source-filter theory of speech production
What is an ldquoAcousticrdquo Filter
bull holds back (attenuates) certain sounds and lets other sounds through - selective
Why might we be interested in filters
bull Human vocal tract acts like a frequency selective acoustic filter
bull Human auditory system behaves as a frequency selective filter
bull helps us understand how speech is produced and perceived
Kinds of frequency selective filters
Low-pass filtersndash Lets low frequencies ldquopass throughrdquo and attenuates high
frequencies
High-pass filtersndash Lets high frequencies ldquopass throughrdquo and attenuates low
frequencies
Band-pass filtersndash Lets a particular frequency range ldquopass throughrdquo and
attenuates other frequencies
Low Pass Filters
Frequencylow high
Gai
n
+
-
High Pass Filters
Frequencylow high
Gai
n
+
-
Band Pass Filter
Frequencylow high
Gai
n
+
-
Frequency Response Curve (FRC)
Frequencylow high
Gai
n
+
-
Center frequency
lower cutofffrequency
upper cutoff frequency
passband
3 dB
Operation of a filter on a signal
NOTE Amplitude spectrum describes a soundFrequency response curve describes a filter
Learning Objectivesbull Define resonance free and forced vibrationbull Describe how the pendulum and spring mass models can
help explain resonancebull Outline how mass and stiffness influences the resonant
frequency of a mass spring systembull Outline how acoustic resonators behave like acoustic filtersbull Calculate resonant frequencies of a uniform tube based on
its physical dimensionsbull Describe how the wavelength of the sound determines the
resonant frequency of tube
Free vibration
bull objects tend to vibrate at a characteristic or resonant frequency (RF)
Forced vibration
bull A vibrating system can force a nearby system into vibration
bull The efficiency with which this is accomplished is related to the similarity in the resonant frequency (RF) of the two systems
Forced vibration
bull If the RF of the two systems are the same the amplitude of forced vibration will be large
bull If the RF of the two systems are quite different the amplitude of forced vibration will be small or nonexistent
Resonance refers to
bull The tendency for an object to vibrate at a particular frequency or frequencies
bull The ability of a vibrating system to force another system into vibration
Back to the mass spring model
bull Vibratory frequency of the mass spring determined byndash Massndash Stiffness of the spring
httpphetcoloradoeduensimulationmass-spring-lab
Acoustic Resonance
bull Ideas from mechanical resonance also applies to acoustic systems
bull Acoustic chambers will transmit sound frequencies with more or less efficiency depending upon the physical characteristics
bull Therefore they act as filters passing through (and even amplifying) some frequencies and attentuating others
Acoustic Resonance
bull And since they act as filters they have most of the same features of a filter even though we might use different names
bull Center frequency is often termed the resonant frequency
bull Frequency response curve often termed the resonance curve
Helmholtz Resonator
Actions of a Helmholtz Resonator
Stephen M Tasko
Other Acoustic Resonators Tube Resonators
bull Uniform tubes Factors that influence resonancendash Lengthndash Cross-sectional area along its lengthndash Whether it is closed at either or both ends
Uniform tube closed at one end
Uniform tube closed at one end
Stephen M Tasko
Uniform tube closed at one end
First resonance or formant
F1 = c4lWhere
c=speed of sound (35000 cmsec)l = length of the tube
males ~ 175 cmfemales ~ 14 cm
Higher resonantformant frequencies are odd multiples of F1
For examplebull F1 = (c4l )1
bull F2 = (c4l )3
bull F3 = (c4l )5
Comparing Helmholtz and tube resonators
Resonator Features
Sharply tuned Broadly tuned
Resonator Features
An example of the resonance characteristics of the human vocal tract
Frequency
Gain
SPPA 4030 Speech Science
Topic 1 The Speech Chain
The Speech Chain (Denes amp Pinson 1993)
What information is embedded in the speech signal
Branches of science employed to understand speech communication
Physical Quantities Review An Independent Learning Activity
Assignment 1
Topic 2 The Source-Filter Theory of Speech Production An Intr
Producing Speech
Source-Filter Theory of Speech Production
Vocal tract is a tube that can vary its shape
Source Filter Theory
Same Source Different Filter
Different Source Same Filters
Different Source Same Filters (Human)
Different Source Same Filters (Human) (2)
Different Source Same Filters (Human) (3)
Different Source Same Filters (Human) (4)
Different Source Same Filters (Non-Human)
Different Source Same Filters (Non-Human) (2)
Different Source Same Filters (Non-Human) If it quacks like a
Source Filter Theory Applied Alaryngeal Speech
Source-Filter Theory Applied Esophageal Insufflation Test
Source-Filter Theory Applied Tracheoesophageal (TE) Speech
Source Filter Theory Applied The Talkbox
Source-Filter Theory Applied The Talkbox
Topic 3 A Brief Review of Physical Acoustics
Spring Mass Model
What is sound
Sound-conducting media
Model of air molecule vibration (Time 1)
Model of air molecule vibration (Time 2)
Model of air molecule vibration (Time 3)
Model of air molecule vibration (Time 4)
Model of air molecule vibration (Time 5)
Model of air molecule vibration
Wave action of molecular motion
Amplitude waveform
Amplitude waveform (2)
Where is pressure in this model
Pressure waveform
Measuring Sound
Measuring Sound Signal Amplitude
Measuring Sound Signal Amplitude (2)
What units do we use to measure signal amplitude
Brief Review The decibel scale
Absolute vs relative measurement
Typical reference values
Howeverhellip
Linear vs logarithmic
Linear vs logarithmic (2)
Logarithmic Scale
Logarithmic Scale (2)
Combining the idea of logarithmic and relativehellip
Intensity vs Pressure
Extending the formula to pressure
Measuring Sound Frequencyperiod
Measuring Sound Frequencyperiod (2)
Phase Uniform Circular Motion
Initiating a sound waves that differ only in phase
Spatial variation in pressure wave
Spatial variation in pressure wave
Spatial variation in pressure wave (2)
Relation between frequency and wavelength
Learning Objectives
Graphic representation of sound
Same sound different graphs
Classification of sounds
Simple periodic sound
Simple periodic sound Graphic appearance
Complex periodic sounds
Complex periodic sounds Graphic appearance
Complex periodic sounds Graphic appearance (2)
Glottal Source
Amplitude vs Phase Spectrum
Amplitude vs Phase Spectrum (2)
(Complex) Aperiodic sounds
Aperiodic sounds Graphic appearance
Aperiodic sounds Graphic appearance (2)
Analysis of complex waves
Learning Objectives (2)
The ldquoenveloperdquo of a sound wave
Waveform envelope
Waveform envelope (2)
Spectrum envelope
Thought Question
Amplitude Spectrum Window Size
ldquoInstantaneousrdquo Amplitude Spectra
(Long Term) Average Amplitude Spectrum
Slide 90
Learning Objectives (3)
The Spectrogram
Building a spectrogram
Building a spectrogram
Building a spectrogram (2)
Two main types of spectrograms
Wide vs Narrow Band Spectrograms
Learning Objectives (4)
What is an ldquoAcousticrdquo Filter
Why might we be interested in filters
Kinds of frequency selective filters
Low Pass Filters
High Pass Filters
Band Pass Filter
Frequency Response Curve (FRC)
Operation of a filter on a signal
Learning Objectives (5)
Free vibration
Forced vibration
Forced vibration (2)
Resonance refers to
Back to the mass spring model
Acoustic Resonance
Acoustic Resonance (2)
Helmholtz Resonator
Actions of a Helmholtz Resonator
Other Acoustic Resonators Tube Resonators
Uniform tube closed at one end
Uniform tube closed at one end (2)
Uniform tube closed at one end
Comparing Helmholtz and tube resonators
Slide 122
Slide 123
Source Filter Theory Applied Alaryngeal Speech
Source-Filter Theory AppliedEsophageal Insufflation Test
Source-Filter Theory AppliedTracheoesophageal (TE) Speech
Source Filter Theory Applied The Talkbox
Source-Filter Theory Applied The Talkbox
httpwwwyoutubecomwatchv=YS3gAVNlceg
Topic 3 A Brief Review of Physical Acoustics
Learning Objectivesbull Outline the physical processes underlying simple harmonic motion using the
mass-spring modelbull Describe the molecular basis of sound wave propagationbull Define the key characteristics of sinusoidal motion including
ndash Amplitude instantaneous peak peak-to-peak root-mean-square (RMS) the decibel scale
ndash Frequencyperiod including units of measurendash Phasendash Wavelength
bull Briefly describe the relation between the sine wave and uniform circular motion
bull Outline the relationship between the frequency and wavelength of a sound wave
Spring Mass Model
bull Mass (inertia)ndash Newtonrsquos first law of motionndash Opposition to
accelerationdecelerationbull Elasticityndash Opposition to displacementndash Rest positionndash Recoil force
bull Complex gt one frequency componentbull Aperiodic Does not repeat itselfbull Frequency components are not systematically
relatedbull May be ndash Continuousndash Transient
Aperiodic sounds Graphic appearance
bull Time domainndash no repeating pattern of pressure change
bull Frequency domainndash the spectrum is dense ndash No ldquopicket fencerdquo
bull Auditory impression sounds lsquonoisyrsquo
Aperiodic sounds Graphic appearance
From Hillenbrand
>
Analysis of complex wavesbull Waves can be summedbull Complex waves are the sum of simple wavesbull Fourier French Mathematician
ndash Any complex waveform may be formed by summing sinusoids of various frequency amplitude and phase
bull Fourier Analysisndash Provides a unique (only one) solution for a given sound signalndash Is reflected in the amplitude and phase spectrum of the signalndash Reveals the building blocks of complex waves which are sinusoids
Learning Objectives
bull Draw and differentiate the waveform and the waveform envelope
bull Draw and differentiate the amplitude spectrum the phase spectrum and the spectrum envelope
bull Differential between short-term spectra and long-term average spectra
The ldquoenveloperdquo of a sound wave
bull Waveform envelopendash imaginary smooth line that follows the peak of the
amplitude of a sound pressure waveformbull Spectrum envelopendash Imaginary smooth line drawn on top of the
amplitude spectrum
Waveform envelope
From Hillenbrand
Waveform envelope
Time
>
Spectrum envelope
Frequency
Ampl
itude
Thought Question
Can an aperiodic and complex periodic sound have identical
spectrum envelopes
Amplitude Spectrum Window Size
bull ldquoshort-termrdquo vs ldquolong-term averagerdquo amplitude spectrum
ldquoInstantaneousrdquo Amplitude Spectra
(Long Term) Average Amplitude Spectrum
Learning Objectivesbull Describe how the amplitude spectrum and the spectrogram are
relatedbull Identify the axis units of the spectrogrambull Provide some advantages of the spectrogram over the
amplitude spectrumbull Distinguish between a wide band and narrow band spectrogram
and outline the different information each providesbull Distinguish between a harmonic and a formant on a
spectrogrambull Be able to draw stylized (highly simplified) spectrograms based
on spectra and spectrum envelopes
The Spectrogram
Rotate90 degrees
F
AF
A
Building a spectrogram
Rotate it so thatThe amplitude isComing out of thepage
F
A This is really narrow because it is a slice in time
F
Time
Building a spectrogram
Dark bands= amplitudePeaks
Time
Freq
uenc
y
Building a spectrogram
Two main types of spectrograms
bull Narrow-band spectrogramsndash Akin to amplitude spectrums ldquolined uprdquondash Frequency resolution is really sharp
bull Wide-band spectrogramsndash Akin to spectrum envelopes ldquolined uprdquondash Frequency resolution not so sharp
Highlights harmonic structure
Highlights spectrum envelope
Wide vs Narrow Band Spectrograms
Learning Objectives
bull Define an acoustic filterbull Draw and label a frequency response curvebull Draw and differentiate different types of acoustic
filtersbull Define terms such as cutoff frequency center
frequency roll off rate gain and bandwidthbull Define and draw a basic filter system and relate that
to the source-filter theory of speech production
What is an ldquoAcousticrdquo Filter
bull holds back (attenuates) certain sounds and lets other sounds through - selective
Why might we be interested in filters
bull Human vocal tract acts like a frequency selective acoustic filter
bull Human auditory system behaves as a frequency selective filter
bull helps us understand how speech is produced and perceived
Kinds of frequency selective filters
Low-pass filtersndash Lets low frequencies ldquopass throughrdquo and attenuates high
frequencies
High-pass filtersndash Lets high frequencies ldquopass throughrdquo and attenuates low
frequencies
Band-pass filtersndash Lets a particular frequency range ldquopass throughrdquo and
attenuates other frequencies
Low Pass Filters
Frequencylow high
Gai
n
+
-
High Pass Filters
Frequencylow high
Gai
n
+
-
Band Pass Filter
Frequencylow high
Gai
n
+
-
Frequency Response Curve (FRC)
Frequencylow high
Gai
n
+
-
Center frequency
lower cutofffrequency
upper cutoff frequency
passband
3 dB
Operation of a filter on a signal
NOTE Amplitude spectrum describes a soundFrequency response curve describes a filter
Learning Objectivesbull Define resonance free and forced vibrationbull Describe how the pendulum and spring mass models can
help explain resonancebull Outline how mass and stiffness influences the resonant
frequency of a mass spring systembull Outline how acoustic resonators behave like acoustic filtersbull Calculate resonant frequencies of a uniform tube based on
its physical dimensionsbull Describe how the wavelength of the sound determines the
resonant frequency of tube
Free vibration
bull objects tend to vibrate at a characteristic or resonant frequency (RF)
Forced vibration
bull A vibrating system can force a nearby system into vibration
bull The efficiency with which this is accomplished is related to the similarity in the resonant frequency (RF) of the two systems
Forced vibration
bull If the RF of the two systems are the same the amplitude of forced vibration will be large
bull If the RF of the two systems are quite different the amplitude of forced vibration will be small or nonexistent
Resonance refers to
bull The tendency for an object to vibrate at a particular frequency or frequencies
bull The ability of a vibrating system to force another system into vibration
Back to the mass spring model
bull Vibratory frequency of the mass spring determined byndash Massndash Stiffness of the spring
httpphetcoloradoeduensimulationmass-spring-lab
Acoustic Resonance
bull Ideas from mechanical resonance also applies to acoustic systems
bull Acoustic chambers will transmit sound frequencies with more or less efficiency depending upon the physical characteristics
bull Therefore they act as filters passing through (and even amplifying) some frequencies and attentuating others
Acoustic Resonance
bull And since they act as filters they have most of the same features of a filter even though we might use different names
bull Center frequency is often termed the resonant frequency
bull Frequency response curve often termed the resonance curve
Helmholtz Resonator
Actions of a Helmholtz Resonator
Stephen M Tasko
Other Acoustic Resonators Tube Resonators
bull Uniform tubes Factors that influence resonancendash Lengthndash Cross-sectional area along its lengthndash Whether it is closed at either or both ends
Uniform tube closed at one end
Uniform tube closed at one end
Stephen M Tasko
Uniform tube closed at one end
First resonance or formant
F1 = c4lWhere
c=speed of sound (35000 cmsec)l = length of the tube
males ~ 175 cmfemales ~ 14 cm
Higher resonantformant frequencies are odd multiples of F1
For examplebull F1 = (c4l )1
bull F2 = (c4l )3
bull F3 = (c4l )5
Comparing Helmholtz and tube resonators
Resonator Features
Sharply tuned Broadly tuned
Resonator Features
An example of the resonance characteristics of the human vocal tract
Frequency
Gain
SPPA 4030 Speech Science
Topic 1 The Speech Chain
The Speech Chain (Denes amp Pinson 1993)
What information is embedded in the speech signal
Branches of science employed to understand speech communication
Physical Quantities Review An Independent Learning Activity
Assignment 1
Topic 2 The Source-Filter Theory of Speech Production An Intr
Producing Speech
Source-Filter Theory of Speech Production
Vocal tract is a tube that can vary its shape
Source Filter Theory
Same Source Different Filter
Different Source Same Filters
Different Source Same Filters (Human)
Different Source Same Filters (Human) (2)
Different Source Same Filters (Human) (3)
Different Source Same Filters (Human) (4)
Different Source Same Filters (Non-Human)
Different Source Same Filters (Non-Human) (2)
Different Source Same Filters (Non-Human) If it quacks like a
Source Filter Theory Applied Alaryngeal Speech
Source-Filter Theory Applied Esophageal Insufflation Test
Source-Filter Theory Applied Tracheoesophageal (TE) Speech
Source Filter Theory Applied The Talkbox
Source-Filter Theory Applied The Talkbox
Topic 3 A Brief Review of Physical Acoustics
Spring Mass Model
What is sound
Sound-conducting media
Model of air molecule vibration (Time 1)
Model of air molecule vibration (Time 2)
Model of air molecule vibration (Time 3)
Model of air molecule vibration (Time 4)
Model of air molecule vibration (Time 5)
Model of air molecule vibration
Wave action of molecular motion
Amplitude waveform
Amplitude waveform (2)
Where is pressure in this model
Pressure waveform
Measuring Sound
Measuring Sound Signal Amplitude
Measuring Sound Signal Amplitude (2)
What units do we use to measure signal amplitude
Brief Review The decibel scale
Absolute vs relative measurement
Typical reference values
Howeverhellip
Linear vs logarithmic
Linear vs logarithmic (2)
Logarithmic Scale
Logarithmic Scale (2)
Combining the idea of logarithmic and relativehellip
Intensity vs Pressure
Extending the formula to pressure
Measuring Sound Frequencyperiod
Measuring Sound Frequencyperiod (2)
Phase Uniform Circular Motion
Initiating a sound waves that differ only in phase
Spatial variation in pressure wave
Spatial variation in pressure wave
Spatial variation in pressure wave (2)
Relation between frequency and wavelength
Learning Objectives
Graphic representation of sound
Same sound different graphs
Classification of sounds
Simple periodic sound
Simple periodic sound Graphic appearance
Complex periodic sounds
Complex periodic sounds Graphic appearance
Complex periodic sounds Graphic appearance (2)
Glottal Source
Amplitude vs Phase Spectrum
Amplitude vs Phase Spectrum (2)
(Complex) Aperiodic sounds
Aperiodic sounds Graphic appearance
Aperiodic sounds Graphic appearance (2)
Analysis of complex waves
Learning Objectives (2)
The ldquoenveloperdquo of a sound wave
Waveform envelope
Waveform envelope (2)
Spectrum envelope
Thought Question
Amplitude Spectrum Window Size
ldquoInstantaneousrdquo Amplitude Spectra
(Long Term) Average Amplitude Spectrum
Slide 90
Learning Objectives (3)
The Spectrogram
Building a spectrogram
Building a spectrogram
Building a spectrogram (2)
Two main types of spectrograms
Wide vs Narrow Band Spectrograms
Learning Objectives (4)
What is an ldquoAcousticrdquo Filter
Why might we be interested in filters
Kinds of frequency selective filters
Low Pass Filters
High Pass Filters
Band Pass Filter
Frequency Response Curve (FRC)
Operation of a filter on a signal
Learning Objectives (5)
Free vibration
Forced vibration
Forced vibration (2)
Resonance refers to
Back to the mass spring model
Acoustic Resonance
Acoustic Resonance (2)
Helmholtz Resonator
Actions of a Helmholtz Resonator
Other Acoustic Resonators Tube Resonators
Uniform tube closed at one end
Uniform tube closed at one end (2)
Uniform tube closed at one end
Comparing Helmholtz and tube resonators
Slide 122
Slide 123
Source-Filter Theory AppliedEsophageal Insufflation Test
Source-Filter Theory AppliedTracheoesophageal (TE) Speech
Source Filter Theory Applied The Talkbox
Source-Filter Theory Applied The Talkbox
httpwwwyoutubecomwatchv=YS3gAVNlceg
Topic 3 A Brief Review of Physical Acoustics
Learning Objectivesbull Outline the physical processes underlying simple harmonic motion using the
mass-spring modelbull Describe the molecular basis of sound wave propagationbull Define the key characteristics of sinusoidal motion including
ndash Amplitude instantaneous peak peak-to-peak root-mean-square (RMS) the decibel scale
ndash Frequencyperiod including units of measurendash Phasendash Wavelength
bull Briefly describe the relation between the sine wave and uniform circular motion
bull Outline the relationship between the frequency and wavelength of a sound wave
Spring Mass Model
bull Mass (inertia)ndash Newtonrsquos first law of motionndash Opposition to
accelerationdecelerationbull Elasticityndash Opposition to displacementndash Rest positionndash Recoil force
bull Complex gt one frequency componentbull Aperiodic Does not repeat itselfbull Frequency components are not systematically
relatedbull May be ndash Continuousndash Transient
Aperiodic sounds Graphic appearance
bull Time domainndash no repeating pattern of pressure change
bull Frequency domainndash the spectrum is dense ndash No ldquopicket fencerdquo
bull Auditory impression sounds lsquonoisyrsquo
Aperiodic sounds Graphic appearance
From Hillenbrand
>
Analysis of complex wavesbull Waves can be summedbull Complex waves are the sum of simple wavesbull Fourier French Mathematician
ndash Any complex waveform may be formed by summing sinusoids of various frequency amplitude and phase
bull Fourier Analysisndash Provides a unique (only one) solution for a given sound signalndash Is reflected in the amplitude and phase spectrum of the signalndash Reveals the building blocks of complex waves which are sinusoids
Learning Objectives
bull Draw and differentiate the waveform and the waveform envelope
bull Draw and differentiate the amplitude spectrum the phase spectrum and the spectrum envelope
bull Differential between short-term spectra and long-term average spectra
The ldquoenveloperdquo of a sound wave
bull Waveform envelopendash imaginary smooth line that follows the peak of the
amplitude of a sound pressure waveformbull Spectrum envelopendash Imaginary smooth line drawn on top of the
amplitude spectrum
Waveform envelope
From Hillenbrand
Waveform envelope
Time
>
Spectrum envelope
Frequency
Ampl
itude
Thought Question
Can an aperiodic and complex periodic sound have identical
spectrum envelopes
Amplitude Spectrum Window Size
bull ldquoshort-termrdquo vs ldquolong-term averagerdquo amplitude spectrum
ldquoInstantaneousrdquo Amplitude Spectra
(Long Term) Average Amplitude Spectrum
Learning Objectivesbull Describe how the amplitude spectrum and the spectrogram are
relatedbull Identify the axis units of the spectrogrambull Provide some advantages of the spectrogram over the
amplitude spectrumbull Distinguish between a wide band and narrow band spectrogram
and outline the different information each providesbull Distinguish between a harmonic and a formant on a
spectrogrambull Be able to draw stylized (highly simplified) spectrograms based
on spectra and spectrum envelopes
The Spectrogram
Rotate90 degrees
F
AF
A
Building a spectrogram
Rotate it so thatThe amplitude isComing out of thepage
F
A This is really narrow because it is a slice in time
F
Time
Building a spectrogram
Dark bands= amplitudePeaks
Time
Freq
uenc
y
Building a spectrogram
Two main types of spectrograms
bull Narrow-band spectrogramsndash Akin to amplitude spectrums ldquolined uprdquondash Frequency resolution is really sharp
bull Wide-band spectrogramsndash Akin to spectrum envelopes ldquolined uprdquondash Frequency resolution not so sharp
Highlights harmonic structure
Highlights spectrum envelope
Wide vs Narrow Band Spectrograms
Learning Objectives
bull Define an acoustic filterbull Draw and label a frequency response curvebull Draw and differentiate different types of acoustic
filtersbull Define terms such as cutoff frequency center
frequency roll off rate gain and bandwidthbull Define and draw a basic filter system and relate that
to the source-filter theory of speech production
What is an ldquoAcousticrdquo Filter
bull holds back (attenuates) certain sounds and lets other sounds through - selective
Why might we be interested in filters
bull Human vocal tract acts like a frequency selective acoustic filter
bull Human auditory system behaves as a frequency selective filter
bull helps us understand how speech is produced and perceived
Kinds of frequency selective filters
Low-pass filtersndash Lets low frequencies ldquopass throughrdquo and attenuates high
frequencies
High-pass filtersndash Lets high frequencies ldquopass throughrdquo and attenuates low
frequencies
Band-pass filtersndash Lets a particular frequency range ldquopass throughrdquo and
attenuates other frequencies
Low Pass Filters
Frequencylow high
Gai
n
+
-
High Pass Filters
Frequencylow high
Gai
n
+
-
Band Pass Filter
Frequencylow high
Gai
n
+
-
Frequency Response Curve (FRC)
Frequencylow high
Gai
n
+
-
Center frequency
lower cutofffrequency
upper cutoff frequency
passband
3 dB
Operation of a filter on a signal
NOTE Amplitude spectrum describes a soundFrequency response curve describes a filter
Learning Objectivesbull Define resonance free and forced vibrationbull Describe how the pendulum and spring mass models can
help explain resonancebull Outline how mass and stiffness influences the resonant
frequency of a mass spring systembull Outline how acoustic resonators behave like acoustic filtersbull Calculate resonant frequencies of a uniform tube based on
its physical dimensionsbull Describe how the wavelength of the sound determines the
resonant frequency of tube
Free vibration
bull objects tend to vibrate at a characteristic or resonant frequency (RF)
Forced vibration
bull A vibrating system can force a nearby system into vibration
bull The efficiency with which this is accomplished is related to the similarity in the resonant frequency (RF) of the two systems
Forced vibration
bull If the RF of the two systems are the same the amplitude of forced vibration will be large
bull If the RF of the two systems are quite different the amplitude of forced vibration will be small or nonexistent
Resonance refers to
bull The tendency for an object to vibrate at a particular frequency or frequencies
bull The ability of a vibrating system to force another system into vibration
Back to the mass spring model
bull Vibratory frequency of the mass spring determined byndash Massndash Stiffness of the spring
httpphetcoloradoeduensimulationmass-spring-lab
Acoustic Resonance
bull Ideas from mechanical resonance also applies to acoustic systems
bull Acoustic chambers will transmit sound frequencies with more or less efficiency depending upon the physical characteristics
bull Therefore they act as filters passing through (and even amplifying) some frequencies and attentuating others
Acoustic Resonance
bull And since they act as filters they have most of the same features of a filter even though we might use different names
bull Center frequency is often termed the resonant frequency
bull Frequency response curve often termed the resonance curve
Helmholtz Resonator
Actions of a Helmholtz Resonator
Stephen M Tasko
Other Acoustic Resonators Tube Resonators
bull Uniform tubes Factors that influence resonancendash Lengthndash Cross-sectional area along its lengthndash Whether it is closed at either or both ends
Uniform tube closed at one end
Uniform tube closed at one end
Stephen M Tasko
Uniform tube closed at one end
First resonance or formant
F1 = c4lWhere
c=speed of sound (35000 cmsec)l = length of the tube
males ~ 175 cmfemales ~ 14 cm
Higher resonantformant frequencies are odd multiples of F1
For examplebull F1 = (c4l )1
bull F2 = (c4l )3
bull F3 = (c4l )5
Comparing Helmholtz and tube resonators
Resonator Features
Sharply tuned Broadly tuned
Resonator Features
An example of the resonance characteristics of the human vocal tract
Frequency
Gain
SPPA 4030 Speech Science
Topic 1 The Speech Chain
The Speech Chain (Denes amp Pinson 1993)
What information is embedded in the speech signal
Branches of science employed to understand speech communication
Physical Quantities Review An Independent Learning Activity
Assignment 1
Topic 2 The Source-Filter Theory of Speech Production An Intr
Producing Speech
Source-Filter Theory of Speech Production
Vocal tract is a tube that can vary its shape
Source Filter Theory
Same Source Different Filter
Different Source Same Filters
Different Source Same Filters (Human)
Different Source Same Filters (Human) (2)
Different Source Same Filters (Human) (3)
Different Source Same Filters (Human) (4)
Different Source Same Filters (Non-Human)
Different Source Same Filters (Non-Human) (2)
Different Source Same Filters (Non-Human) If it quacks like a
Source Filter Theory Applied Alaryngeal Speech
Source-Filter Theory Applied Esophageal Insufflation Test
Source-Filter Theory Applied Tracheoesophageal (TE) Speech
Source Filter Theory Applied The Talkbox
Source-Filter Theory Applied The Talkbox
Topic 3 A Brief Review of Physical Acoustics
Spring Mass Model
What is sound
Sound-conducting media
Model of air molecule vibration (Time 1)
Model of air molecule vibration (Time 2)
Model of air molecule vibration (Time 3)
Model of air molecule vibration (Time 4)
Model of air molecule vibration (Time 5)
Model of air molecule vibration
Wave action of molecular motion
Amplitude waveform
Amplitude waveform (2)
Where is pressure in this model
Pressure waveform
Measuring Sound
Measuring Sound Signal Amplitude
Measuring Sound Signal Amplitude (2)
What units do we use to measure signal amplitude
Brief Review The decibel scale
Absolute vs relative measurement
Typical reference values
Howeverhellip
Linear vs logarithmic
Linear vs logarithmic (2)
Logarithmic Scale
Logarithmic Scale (2)
Combining the idea of logarithmic and relativehellip
Intensity vs Pressure
Extending the formula to pressure
Measuring Sound Frequencyperiod
Measuring Sound Frequencyperiod (2)
Phase Uniform Circular Motion
Initiating a sound waves that differ only in phase
Spatial variation in pressure wave
Spatial variation in pressure wave
Spatial variation in pressure wave (2)
Relation between frequency and wavelength
Learning Objectives
Graphic representation of sound
Same sound different graphs
Classification of sounds
Simple periodic sound
Simple periodic sound Graphic appearance
Complex periodic sounds
Complex periodic sounds Graphic appearance
Complex periodic sounds Graphic appearance (2)
Glottal Source
Amplitude vs Phase Spectrum
Amplitude vs Phase Spectrum (2)
(Complex) Aperiodic sounds
Aperiodic sounds Graphic appearance
Aperiodic sounds Graphic appearance (2)
Analysis of complex waves
Learning Objectives (2)
The ldquoenveloperdquo of a sound wave
Waveform envelope
Waveform envelope (2)
Spectrum envelope
Thought Question
Amplitude Spectrum Window Size
ldquoInstantaneousrdquo Amplitude Spectra
(Long Term) Average Amplitude Spectrum
Slide 90
Learning Objectives (3)
The Spectrogram
Building a spectrogram
Building a spectrogram
Building a spectrogram (2)
Two main types of spectrograms
Wide vs Narrow Band Spectrograms
Learning Objectives (4)
What is an ldquoAcousticrdquo Filter
Why might we be interested in filters
Kinds of frequency selective filters
Low Pass Filters
High Pass Filters
Band Pass Filter
Frequency Response Curve (FRC)
Operation of a filter on a signal
Learning Objectives (5)
Free vibration
Forced vibration
Forced vibration (2)
Resonance refers to
Back to the mass spring model
Acoustic Resonance
Acoustic Resonance (2)
Helmholtz Resonator
Actions of a Helmholtz Resonator
Other Acoustic Resonators Tube Resonators
Uniform tube closed at one end
Uniform tube closed at one end (2)
Uniform tube closed at one end
Comparing Helmholtz and tube resonators
Slide 122
Slide 123
Source-Filter Theory AppliedTracheoesophageal (TE) Speech
Source Filter Theory Applied The Talkbox
Source-Filter Theory Applied The Talkbox
httpwwwyoutubecomwatchv=YS3gAVNlceg
Topic 3 A Brief Review of Physical Acoustics
Learning Objectivesbull Outline the physical processes underlying simple harmonic motion using the
mass-spring modelbull Describe the molecular basis of sound wave propagationbull Define the key characteristics of sinusoidal motion including
ndash Amplitude instantaneous peak peak-to-peak root-mean-square (RMS) the decibel scale
ndash Frequencyperiod including units of measurendash Phasendash Wavelength
bull Briefly describe the relation between the sine wave and uniform circular motion
bull Outline the relationship between the frequency and wavelength of a sound wave
Spring Mass Model
bull Mass (inertia)ndash Newtonrsquos first law of motionndash Opposition to
accelerationdecelerationbull Elasticityndash Opposition to displacementndash Rest positionndash Recoil force
bull Complex gt one frequency componentbull Aperiodic Does not repeat itselfbull Frequency components are not systematically
relatedbull May be ndash Continuousndash Transient
Aperiodic sounds Graphic appearance
bull Time domainndash no repeating pattern of pressure change
bull Frequency domainndash the spectrum is dense ndash No ldquopicket fencerdquo
bull Auditory impression sounds lsquonoisyrsquo
Aperiodic sounds Graphic appearance
From Hillenbrand
>
Analysis of complex wavesbull Waves can be summedbull Complex waves are the sum of simple wavesbull Fourier French Mathematician
ndash Any complex waveform may be formed by summing sinusoids of various frequency amplitude and phase
bull Fourier Analysisndash Provides a unique (only one) solution for a given sound signalndash Is reflected in the amplitude and phase spectrum of the signalndash Reveals the building blocks of complex waves which are sinusoids
Learning Objectives
bull Draw and differentiate the waveform and the waveform envelope
bull Draw and differentiate the amplitude spectrum the phase spectrum and the spectrum envelope
bull Differential between short-term spectra and long-term average spectra
The ldquoenveloperdquo of a sound wave
bull Waveform envelopendash imaginary smooth line that follows the peak of the
amplitude of a sound pressure waveformbull Spectrum envelopendash Imaginary smooth line drawn on top of the
amplitude spectrum
Waveform envelope
From Hillenbrand
Waveform envelope
Time
>
Spectrum envelope
Frequency
Ampl
itude
Thought Question
Can an aperiodic and complex periodic sound have identical
spectrum envelopes
Amplitude Spectrum Window Size
bull ldquoshort-termrdquo vs ldquolong-term averagerdquo amplitude spectrum
ldquoInstantaneousrdquo Amplitude Spectra
(Long Term) Average Amplitude Spectrum
Learning Objectivesbull Describe how the amplitude spectrum and the spectrogram are
relatedbull Identify the axis units of the spectrogrambull Provide some advantages of the spectrogram over the
amplitude spectrumbull Distinguish between a wide band and narrow band spectrogram
and outline the different information each providesbull Distinguish between a harmonic and a formant on a
spectrogrambull Be able to draw stylized (highly simplified) spectrograms based
on spectra and spectrum envelopes
The Spectrogram
Rotate90 degrees
F
AF
A
Building a spectrogram
Rotate it so thatThe amplitude isComing out of thepage
F
A This is really narrow because it is a slice in time
F
Time
Building a spectrogram
Dark bands= amplitudePeaks
Time
Freq
uenc
y
Building a spectrogram
Two main types of spectrograms
bull Narrow-band spectrogramsndash Akin to amplitude spectrums ldquolined uprdquondash Frequency resolution is really sharp
bull Wide-band spectrogramsndash Akin to spectrum envelopes ldquolined uprdquondash Frequency resolution not so sharp
Highlights harmonic structure
Highlights spectrum envelope
Wide vs Narrow Band Spectrograms
Learning Objectives
bull Define an acoustic filterbull Draw and label a frequency response curvebull Draw and differentiate different types of acoustic
filtersbull Define terms such as cutoff frequency center
frequency roll off rate gain and bandwidthbull Define and draw a basic filter system and relate that
to the source-filter theory of speech production
What is an ldquoAcousticrdquo Filter
bull holds back (attenuates) certain sounds and lets other sounds through - selective
Why might we be interested in filters
bull Human vocal tract acts like a frequency selective acoustic filter
bull Human auditory system behaves as a frequency selective filter
bull helps us understand how speech is produced and perceived
Kinds of frequency selective filters
Low-pass filtersndash Lets low frequencies ldquopass throughrdquo and attenuates high
frequencies
High-pass filtersndash Lets high frequencies ldquopass throughrdquo and attenuates low
frequencies
Band-pass filtersndash Lets a particular frequency range ldquopass throughrdquo and
attenuates other frequencies
Low Pass Filters
Frequencylow high
Gai
n
+
-
High Pass Filters
Frequencylow high
Gai
n
+
-
Band Pass Filter
Frequencylow high
Gai
n
+
-
Frequency Response Curve (FRC)
Frequencylow high
Gai
n
+
-
Center frequency
lower cutofffrequency
upper cutoff frequency
passband
3 dB
Operation of a filter on a signal
NOTE Amplitude spectrum describes a soundFrequency response curve describes a filter
Learning Objectivesbull Define resonance free and forced vibrationbull Describe how the pendulum and spring mass models can
help explain resonancebull Outline how mass and stiffness influences the resonant
frequency of a mass spring systembull Outline how acoustic resonators behave like acoustic filtersbull Calculate resonant frequencies of a uniform tube based on
its physical dimensionsbull Describe how the wavelength of the sound determines the
resonant frequency of tube
Free vibration
bull objects tend to vibrate at a characteristic or resonant frequency (RF)
Forced vibration
bull A vibrating system can force a nearby system into vibration
bull The efficiency with which this is accomplished is related to the similarity in the resonant frequency (RF) of the two systems
Forced vibration
bull If the RF of the two systems are the same the amplitude of forced vibration will be large
bull If the RF of the two systems are quite different the amplitude of forced vibration will be small or nonexistent
Resonance refers to
bull The tendency for an object to vibrate at a particular frequency or frequencies
bull The ability of a vibrating system to force another system into vibration
Back to the mass spring model
bull Vibratory frequency of the mass spring determined byndash Massndash Stiffness of the spring
httpphetcoloradoeduensimulationmass-spring-lab
Acoustic Resonance
bull Ideas from mechanical resonance also applies to acoustic systems
bull Acoustic chambers will transmit sound frequencies with more or less efficiency depending upon the physical characteristics
bull Therefore they act as filters passing through (and even amplifying) some frequencies and attentuating others
Acoustic Resonance
bull And since they act as filters they have most of the same features of a filter even though we might use different names
bull Center frequency is often termed the resonant frequency
bull Frequency response curve often termed the resonance curve
Helmholtz Resonator
Actions of a Helmholtz Resonator
Stephen M Tasko
Other Acoustic Resonators Tube Resonators
bull Uniform tubes Factors that influence resonancendash Lengthndash Cross-sectional area along its lengthndash Whether it is closed at either or both ends
Uniform tube closed at one end
Uniform tube closed at one end
Stephen M Tasko
Uniform tube closed at one end
First resonance or formant
F1 = c4lWhere
c=speed of sound (35000 cmsec)l = length of the tube
males ~ 175 cmfemales ~ 14 cm
Higher resonantformant frequencies are odd multiples of F1
For examplebull F1 = (c4l )1
bull F2 = (c4l )3
bull F3 = (c4l )5
Comparing Helmholtz and tube resonators
Resonator Features
Sharply tuned Broadly tuned
Resonator Features
An example of the resonance characteristics of the human vocal tract
Frequency
Gain
SPPA 4030 Speech Science
Topic 1 The Speech Chain
The Speech Chain (Denes amp Pinson 1993)
What information is embedded in the speech signal
Branches of science employed to understand speech communication
Physical Quantities Review An Independent Learning Activity
Assignment 1
Topic 2 The Source-Filter Theory of Speech Production An Intr
Producing Speech
Source-Filter Theory of Speech Production
Vocal tract is a tube that can vary its shape
Source Filter Theory
Same Source Different Filter
Different Source Same Filters
Different Source Same Filters (Human)
Different Source Same Filters (Human) (2)
Different Source Same Filters (Human) (3)
Different Source Same Filters (Human) (4)
Different Source Same Filters (Non-Human)
Different Source Same Filters (Non-Human) (2)
Different Source Same Filters (Non-Human) If it quacks like a
Source Filter Theory Applied Alaryngeal Speech
Source-Filter Theory Applied Esophageal Insufflation Test
Source-Filter Theory Applied Tracheoesophageal (TE) Speech
Source Filter Theory Applied The Talkbox
Source-Filter Theory Applied The Talkbox
Topic 3 A Brief Review of Physical Acoustics
Spring Mass Model
What is sound
Sound-conducting media
Model of air molecule vibration (Time 1)
Model of air molecule vibration (Time 2)
Model of air molecule vibration (Time 3)
Model of air molecule vibration (Time 4)
Model of air molecule vibration (Time 5)
Model of air molecule vibration
Wave action of molecular motion
Amplitude waveform
Amplitude waveform (2)
Where is pressure in this model
Pressure waveform
Measuring Sound
Measuring Sound Signal Amplitude
Measuring Sound Signal Amplitude (2)
What units do we use to measure signal amplitude
Brief Review The decibel scale
Absolute vs relative measurement
Typical reference values
Howeverhellip
Linear vs logarithmic
Linear vs logarithmic (2)
Logarithmic Scale
Logarithmic Scale (2)
Combining the idea of logarithmic and relativehellip
Intensity vs Pressure
Extending the formula to pressure
Measuring Sound Frequencyperiod
Measuring Sound Frequencyperiod (2)
Phase Uniform Circular Motion
Initiating a sound waves that differ only in phase
Spatial variation in pressure wave
Spatial variation in pressure wave
Spatial variation in pressure wave (2)
Relation between frequency and wavelength
Learning Objectives
Graphic representation of sound
Same sound different graphs
Classification of sounds
Simple periodic sound
Simple periodic sound Graphic appearance
Complex periodic sounds
Complex periodic sounds Graphic appearance
Complex periodic sounds Graphic appearance (2)
Glottal Source
Amplitude vs Phase Spectrum
Amplitude vs Phase Spectrum (2)
(Complex) Aperiodic sounds
Aperiodic sounds Graphic appearance
Aperiodic sounds Graphic appearance (2)
Analysis of complex waves
Learning Objectives (2)
The ldquoenveloperdquo of a sound wave
Waveform envelope
Waveform envelope (2)
Spectrum envelope
Thought Question
Amplitude Spectrum Window Size
ldquoInstantaneousrdquo Amplitude Spectra
(Long Term) Average Amplitude Spectrum
Slide 90
Learning Objectives (3)
The Spectrogram
Building a spectrogram
Building a spectrogram
Building a spectrogram (2)
Two main types of spectrograms
Wide vs Narrow Band Spectrograms
Learning Objectives (4)
What is an ldquoAcousticrdquo Filter
Why might we be interested in filters
Kinds of frequency selective filters
Low Pass Filters
High Pass Filters
Band Pass Filter
Frequency Response Curve (FRC)
Operation of a filter on a signal
Learning Objectives (5)
Free vibration
Forced vibration
Forced vibration (2)
Resonance refers to
Back to the mass spring model
Acoustic Resonance
Acoustic Resonance (2)
Helmholtz Resonator
Actions of a Helmholtz Resonator
Other Acoustic Resonators Tube Resonators
Uniform tube closed at one end
Uniform tube closed at one end (2)
Uniform tube closed at one end
Comparing Helmholtz and tube resonators
Slide 122
Slide 123
Source Filter Theory Applied The Talkbox
Source-Filter Theory Applied The Talkbox
httpwwwyoutubecomwatchv=YS3gAVNlceg
Topic 3 A Brief Review of Physical Acoustics
Learning Objectivesbull Outline the physical processes underlying simple harmonic motion using the
mass-spring modelbull Describe the molecular basis of sound wave propagationbull Define the key characteristics of sinusoidal motion including
ndash Amplitude instantaneous peak peak-to-peak root-mean-square (RMS) the decibel scale
ndash Frequencyperiod including units of measurendash Phasendash Wavelength
bull Briefly describe the relation between the sine wave and uniform circular motion
bull Outline the relationship between the frequency and wavelength of a sound wave
Spring Mass Model
bull Mass (inertia)ndash Newtonrsquos first law of motionndash Opposition to
accelerationdecelerationbull Elasticityndash Opposition to displacementndash Rest positionndash Recoil force
bull Complex gt one frequency componentbull Aperiodic Does not repeat itselfbull Frequency components are not systematically
relatedbull May be ndash Continuousndash Transient
Aperiodic sounds Graphic appearance
bull Time domainndash no repeating pattern of pressure change
bull Frequency domainndash the spectrum is dense ndash No ldquopicket fencerdquo
bull Auditory impression sounds lsquonoisyrsquo
Aperiodic sounds Graphic appearance
From Hillenbrand
>
Analysis of complex wavesbull Waves can be summedbull Complex waves are the sum of simple wavesbull Fourier French Mathematician
ndash Any complex waveform may be formed by summing sinusoids of various frequency amplitude and phase
bull Fourier Analysisndash Provides a unique (only one) solution for a given sound signalndash Is reflected in the amplitude and phase spectrum of the signalndash Reveals the building blocks of complex waves which are sinusoids
Learning Objectives
bull Draw and differentiate the waveform and the waveform envelope
bull Draw and differentiate the amplitude spectrum the phase spectrum and the spectrum envelope
bull Differential between short-term spectra and long-term average spectra
The ldquoenveloperdquo of a sound wave
bull Waveform envelopendash imaginary smooth line that follows the peak of the
amplitude of a sound pressure waveformbull Spectrum envelopendash Imaginary smooth line drawn on top of the
amplitude spectrum
Waveform envelope
From Hillenbrand
Waveform envelope
Time
>
Spectrum envelope
Frequency
Ampl
itude
Thought Question
Can an aperiodic and complex periodic sound have identical
spectrum envelopes
Amplitude Spectrum Window Size
bull ldquoshort-termrdquo vs ldquolong-term averagerdquo amplitude spectrum
ldquoInstantaneousrdquo Amplitude Spectra
(Long Term) Average Amplitude Spectrum
Learning Objectivesbull Describe how the amplitude spectrum and the spectrogram are
relatedbull Identify the axis units of the spectrogrambull Provide some advantages of the spectrogram over the
amplitude spectrumbull Distinguish between a wide band and narrow band spectrogram
and outline the different information each providesbull Distinguish between a harmonic and a formant on a
spectrogrambull Be able to draw stylized (highly simplified) spectrograms based
on spectra and spectrum envelopes
The Spectrogram
Rotate90 degrees
F
AF
A
Building a spectrogram
Rotate it so thatThe amplitude isComing out of thepage
F
A This is really narrow because it is a slice in time
F
Time
Building a spectrogram
Dark bands= amplitudePeaks
Time
Freq
uenc
y
Building a spectrogram
Two main types of spectrograms
bull Narrow-band spectrogramsndash Akin to amplitude spectrums ldquolined uprdquondash Frequency resolution is really sharp
bull Wide-band spectrogramsndash Akin to spectrum envelopes ldquolined uprdquondash Frequency resolution not so sharp
Highlights harmonic structure
Highlights spectrum envelope
Wide vs Narrow Band Spectrograms
Learning Objectives
bull Define an acoustic filterbull Draw and label a frequency response curvebull Draw and differentiate different types of acoustic
filtersbull Define terms such as cutoff frequency center
frequency roll off rate gain and bandwidthbull Define and draw a basic filter system and relate that
to the source-filter theory of speech production
What is an ldquoAcousticrdquo Filter
bull holds back (attenuates) certain sounds and lets other sounds through - selective
Why might we be interested in filters
bull Human vocal tract acts like a frequency selective acoustic filter
bull Human auditory system behaves as a frequency selective filter
bull helps us understand how speech is produced and perceived
Kinds of frequency selective filters
Low-pass filtersndash Lets low frequencies ldquopass throughrdquo and attenuates high
frequencies
High-pass filtersndash Lets high frequencies ldquopass throughrdquo and attenuates low
frequencies
Band-pass filtersndash Lets a particular frequency range ldquopass throughrdquo and
attenuates other frequencies
Low Pass Filters
Frequencylow high
Gai
n
+
-
High Pass Filters
Frequencylow high
Gai
n
+
-
Band Pass Filter
Frequencylow high
Gai
n
+
-
Frequency Response Curve (FRC)
Frequencylow high
Gai
n
+
-
Center frequency
lower cutofffrequency
upper cutoff frequency
passband
3 dB
Operation of a filter on a signal
NOTE Amplitude spectrum describes a soundFrequency response curve describes a filter
Learning Objectivesbull Define resonance free and forced vibrationbull Describe how the pendulum and spring mass models can
help explain resonancebull Outline how mass and stiffness influences the resonant
frequency of a mass spring systembull Outline how acoustic resonators behave like acoustic filtersbull Calculate resonant frequencies of a uniform tube based on
its physical dimensionsbull Describe how the wavelength of the sound determines the
resonant frequency of tube
Free vibration
bull objects tend to vibrate at a characteristic or resonant frequency (RF)
Forced vibration
bull A vibrating system can force a nearby system into vibration
bull The efficiency with which this is accomplished is related to the similarity in the resonant frequency (RF) of the two systems
Forced vibration
bull If the RF of the two systems are the same the amplitude of forced vibration will be large
bull If the RF of the two systems are quite different the amplitude of forced vibration will be small or nonexistent
Resonance refers to
bull The tendency for an object to vibrate at a particular frequency or frequencies
bull The ability of a vibrating system to force another system into vibration
Back to the mass spring model
bull Vibratory frequency of the mass spring determined byndash Massndash Stiffness of the spring
httpphetcoloradoeduensimulationmass-spring-lab
Acoustic Resonance
bull Ideas from mechanical resonance also applies to acoustic systems
bull Acoustic chambers will transmit sound frequencies with more or less efficiency depending upon the physical characteristics
bull Therefore they act as filters passing through (and even amplifying) some frequencies and attentuating others
Acoustic Resonance
bull And since they act as filters they have most of the same features of a filter even though we might use different names
bull Center frequency is often termed the resonant frequency
bull Frequency response curve often termed the resonance curve
Helmholtz Resonator
Actions of a Helmholtz Resonator
Stephen M Tasko
Other Acoustic Resonators Tube Resonators
bull Uniform tubes Factors that influence resonancendash Lengthndash Cross-sectional area along its lengthndash Whether it is closed at either or both ends
Uniform tube closed at one end
Uniform tube closed at one end
Stephen M Tasko
Uniform tube closed at one end
First resonance or formant
F1 = c4lWhere
c=speed of sound (35000 cmsec)l = length of the tube
males ~ 175 cmfemales ~ 14 cm
Higher resonantformant frequencies are odd multiples of F1
For examplebull F1 = (c4l )1
bull F2 = (c4l )3
bull F3 = (c4l )5
Comparing Helmholtz and tube resonators
Resonator Features
Sharply tuned Broadly tuned
Resonator Features
An example of the resonance characteristics of the human vocal tract
Frequency
Gain
SPPA 4030 Speech Science
Topic 1 The Speech Chain
The Speech Chain (Denes amp Pinson 1993)
What information is embedded in the speech signal
Branches of science employed to understand speech communication
Physical Quantities Review An Independent Learning Activity
Assignment 1
Topic 2 The Source-Filter Theory of Speech Production An Intr
Producing Speech
Source-Filter Theory of Speech Production
Vocal tract is a tube that can vary its shape
Source Filter Theory
Same Source Different Filter
Different Source Same Filters
Different Source Same Filters (Human)
Different Source Same Filters (Human) (2)
Different Source Same Filters (Human) (3)
Different Source Same Filters (Human) (4)
Different Source Same Filters (Non-Human)
Different Source Same Filters (Non-Human) (2)
Different Source Same Filters (Non-Human) If it quacks like a
Source Filter Theory Applied Alaryngeal Speech
Source-Filter Theory Applied Esophageal Insufflation Test
Source-Filter Theory Applied Tracheoesophageal (TE) Speech
Source Filter Theory Applied The Talkbox
Source-Filter Theory Applied The Talkbox
Topic 3 A Brief Review of Physical Acoustics
Spring Mass Model
What is sound
Sound-conducting media
Model of air molecule vibration (Time 1)
Model of air molecule vibration (Time 2)
Model of air molecule vibration (Time 3)
Model of air molecule vibration (Time 4)
Model of air molecule vibration (Time 5)
Model of air molecule vibration
Wave action of molecular motion
Amplitude waveform
Amplitude waveform (2)
Where is pressure in this model
Pressure waveform
Measuring Sound
Measuring Sound Signal Amplitude
Measuring Sound Signal Amplitude (2)
What units do we use to measure signal amplitude
Brief Review The decibel scale
Absolute vs relative measurement
Typical reference values
Howeverhellip
Linear vs logarithmic
Linear vs logarithmic (2)
Logarithmic Scale
Logarithmic Scale (2)
Combining the idea of logarithmic and relativehellip
Intensity vs Pressure
Extending the formula to pressure
Measuring Sound Frequencyperiod
Measuring Sound Frequencyperiod (2)
Phase Uniform Circular Motion
Initiating a sound waves that differ only in phase
Spatial variation in pressure wave
Spatial variation in pressure wave
Spatial variation in pressure wave (2)
Relation between frequency and wavelength
Learning Objectives
Graphic representation of sound
Same sound different graphs
Classification of sounds
Simple periodic sound
Simple periodic sound Graphic appearance
Complex periodic sounds
Complex periodic sounds Graphic appearance
Complex periodic sounds Graphic appearance (2)
Glottal Source
Amplitude vs Phase Spectrum
Amplitude vs Phase Spectrum (2)
(Complex) Aperiodic sounds
Aperiodic sounds Graphic appearance
Aperiodic sounds Graphic appearance (2)
Analysis of complex waves
Learning Objectives (2)
The ldquoenveloperdquo of a sound wave
Waveform envelope
Waveform envelope (2)
Spectrum envelope
Thought Question
Amplitude Spectrum Window Size
ldquoInstantaneousrdquo Amplitude Spectra
(Long Term) Average Amplitude Spectrum
Slide 90
Learning Objectives (3)
The Spectrogram
Building a spectrogram
Building a spectrogram
Building a spectrogram (2)
Two main types of spectrograms
Wide vs Narrow Band Spectrograms
Learning Objectives (4)
What is an ldquoAcousticrdquo Filter
Why might we be interested in filters
Kinds of frequency selective filters
Low Pass Filters
High Pass Filters
Band Pass Filter
Frequency Response Curve (FRC)
Operation of a filter on a signal
Learning Objectives (5)
Free vibration
Forced vibration
Forced vibration (2)
Resonance refers to
Back to the mass spring model
Acoustic Resonance
Acoustic Resonance (2)
Helmholtz Resonator
Actions of a Helmholtz Resonator
Other Acoustic Resonators Tube Resonators
Uniform tube closed at one end
Uniform tube closed at one end (2)
Uniform tube closed at one end
Comparing Helmholtz and tube resonators
Slide 122
Slide 123
Source-Filter Theory Applied The Talkbox
httpwwwyoutubecomwatchv=YS3gAVNlceg
Topic 3 A Brief Review of Physical Acoustics
Learning Objectivesbull Outline the physical processes underlying simple harmonic motion using the
mass-spring modelbull Describe the molecular basis of sound wave propagationbull Define the key characteristics of sinusoidal motion including
ndash Amplitude instantaneous peak peak-to-peak root-mean-square (RMS) the decibel scale
ndash Frequencyperiod including units of measurendash Phasendash Wavelength
bull Briefly describe the relation between the sine wave and uniform circular motion
bull Outline the relationship between the frequency and wavelength of a sound wave
Spring Mass Model
bull Mass (inertia)ndash Newtonrsquos first law of motionndash Opposition to
accelerationdecelerationbull Elasticityndash Opposition to displacementndash Rest positionndash Recoil force
bull Complex gt one frequency componentbull Aperiodic Does not repeat itselfbull Frequency components are not systematically
relatedbull May be ndash Continuousndash Transient
Aperiodic sounds Graphic appearance
bull Time domainndash no repeating pattern of pressure change
bull Frequency domainndash the spectrum is dense ndash No ldquopicket fencerdquo
bull Auditory impression sounds lsquonoisyrsquo
Aperiodic sounds Graphic appearance
From Hillenbrand
>
Analysis of complex wavesbull Waves can be summedbull Complex waves are the sum of simple wavesbull Fourier French Mathematician
ndash Any complex waveform may be formed by summing sinusoids of various frequency amplitude and phase
bull Fourier Analysisndash Provides a unique (only one) solution for a given sound signalndash Is reflected in the amplitude and phase spectrum of the signalndash Reveals the building blocks of complex waves which are sinusoids
Learning Objectives
bull Draw and differentiate the waveform and the waveform envelope
bull Draw and differentiate the amplitude spectrum the phase spectrum and the spectrum envelope
bull Differential between short-term spectra and long-term average spectra
The ldquoenveloperdquo of a sound wave
bull Waveform envelopendash imaginary smooth line that follows the peak of the
amplitude of a sound pressure waveformbull Spectrum envelopendash Imaginary smooth line drawn on top of the
amplitude spectrum
Waveform envelope
From Hillenbrand
Waveform envelope
Time
>
Spectrum envelope
Frequency
Ampl
itude
Thought Question
Can an aperiodic and complex periodic sound have identical
spectrum envelopes
Amplitude Spectrum Window Size
bull ldquoshort-termrdquo vs ldquolong-term averagerdquo amplitude spectrum
ldquoInstantaneousrdquo Amplitude Spectra
(Long Term) Average Amplitude Spectrum
Learning Objectivesbull Describe how the amplitude spectrum and the spectrogram are
relatedbull Identify the axis units of the spectrogrambull Provide some advantages of the spectrogram over the
amplitude spectrumbull Distinguish between a wide band and narrow band spectrogram
and outline the different information each providesbull Distinguish between a harmonic and a formant on a
spectrogrambull Be able to draw stylized (highly simplified) spectrograms based
on spectra and spectrum envelopes
The Spectrogram
Rotate90 degrees
F
AF
A
Building a spectrogram
Rotate it so thatThe amplitude isComing out of thepage
F
A This is really narrow because it is a slice in time
F
Time
Building a spectrogram
Dark bands= amplitudePeaks
Time
Freq
uenc
y
Building a spectrogram
Two main types of spectrograms
bull Narrow-band spectrogramsndash Akin to amplitude spectrums ldquolined uprdquondash Frequency resolution is really sharp
bull Wide-band spectrogramsndash Akin to spectrum envelopes ldquolined uprdquondash Frequency resolution not so sharp
Highlights harmonic structure
Highlights spectrum envelope
Wide vs Narrow Band Spectrograms
Learning Objectives
bull Define an acoustic filterbull Draw and label a frequency response curvebull Draw and differentiate different types of acoustic
filtersbull Define terms such as cutoff frequency center
frequency roll off rate gain and bandwidthbull Define and draw a basic filter system and relate that
to the source-filter theory of speech production
What is an ldquoAcousticrdquo Filter
bull holds back (attenuates) certain sounds and lets other sounds through - selective
Why might we be interested in filters
bull Human vocal tract acts like a frequency selective acoustic filter
bull Human auditory system behaves as a frequency selective filter
bull helps us understand how speech is produced and perceived
Kinds of frequency selective filters
Low-pass filtersndash Lets low frequencies ldquopass throughrdquo and attenuates high
frequencies
High-pass filtersndash Lets high frequencies ldquopass throughrdquo and attenuates low
frequencies
Band-pass filtersndash Lets a particular frequency range ldquopass throughrdquo and
attenuates other frequencies
Low Pass Filters
Frequencylow high
Gai
n
+
-
High Pass Filters
Frequencylow high
Gai
n
+
-
Band Pass Filter
Frequencylow high
Gai
n
+
-
Frequency Response Curve (FRC)
Frequencylow high
Gai
n
+
-
Center frequency
lower cutofffrequency
upper cutoff frequency
passband
3 dB
Operation of a filter on a signal
NOTE Amplitude spectrum describes a soundFrequency response curve describes a filter
Learning Objectivesbull Define resonance free and forced vibrationbull Describe how the pendulum and spring mass models can
help explain resonancebull Outline how mass and stiffness influences the resonant
frequency of a mass spring systembull Outline how acoustic resonators behave like acoustic filtersbull Calculate resonant frequencies of a uniform tube based on
its physical dimensionsbull Describe how the wavelength of the sound determines the
resonant frequency of tube
Free vibration
bull objects tend to vibrate at a characteristic or resonant frequency (RF)
Forced vibration
bull A vibrating system can force a nearby system into vibration
bull The efficiency with which this is accomplished is related to the similarity in the resonant frequency (RF) of the two systems
Forced vibration
bull If the RF of the two systems are the same the amplitude of forced vibration will be large
bull If the RF of the two systems are quite different the amplitude of forced vibration will be small or nonexistent
Resonance refers to
bull The tendency for an object to vibrate at a particular frequency or frequencies
bull The ability of a vibrating system to force another system into vibration
Back to the mass spring model
bull Vibratory frequency of the mass spring determined byndash Massndash Stiffness of the spring
httpphetcoloradoeduensimulationmass-spring-lab
Acoustic Resonance
bull Ideas from mechanical resonance also applies to acoustic systems
bull Acoustic chambers will transmit sound frequencies with more or less efficiency depending upon the physical characteristics
bull Therefore they act as filters passing through (and even amplifying) some frequencies and attentuating others
Acoustic Resonance
bull And since they act as filters they have most of the same features of a filter even though we might use different names
bull Center frequency is often termed the resonant frequency
bull Frequency response curve often termed the resonance curve
Helmholtz Resonator
Actions of a Helmholtz Resonator
Stephen M Tasko
Other Acoustic Resonators Tube Resonators
bull Uniform tubes Factors that influence resonancendash Lengthndash Cross-sectional area along its lengthndash Whether it is closed at either or both ends
Uniform tube closed at one end
Uniform tube closed at one end
Stephen M Tasko
Uniform tube closed at one end
First resonance or formant
F1 = c4lWhere
c=speed of sound (35000 cmsec)l = length of the tube
males ~ 175 cmfemales ~ 14 cm
Higher resonantformant frequencies are odd multiples of F1
For examplebull F1 = (c4l )1
bull F2 = (c4l )3
bull F3 = (c4l )5
Comparing Helmholtz and tube resonators
Resonator Features
Sharply tuned Broadly tuned
Resonator Features
An example of the resonance characteristics of the human vocal tract
Frequency
Gain
SPPA 4030 Speech Science
Topic 1 The Speech Chain
The Speech Chain (Denes amp Pinson 1993)
What information is embedded in the speech signal
Branches of science employed to understand speech communication
Physical Quantities Review An Independent Learning Activity
Assignment 1
Topic 2 The Source-Filter Theory of Speech Production An Intr
Producing Speech
Source-Filter Theory of Speech Production
Vocal tract is a tube that can vary its shape
Source Filter Theory
Same Source Different Filter
Different Source Same Filters
Different Source Same Filters (Human)
Different Source Same Filters (Human) (2)
Different Source Same Filters (Human) (3)
Different Source Same Filters (Human) (4)
Different Source Same Filters (Non-Human)
Different Source Same Filters (Non-Human) (2)
Different Source Same Filters (Non-Human) If it quacks like a
Source Filter Theory Applied Alaryngeal Speech
Source-Filter Theory Applied Esophageal Insufflation Test
Source-Filter Theory Applied Tracheoesophageal (TE) Speech
Source Filter Theory Applied The Talkbox
Source-Filter Theory Applied The Talkbox
Topic 3 A Brief Review of Physical Acoustics
Spring Mass Model
What is sound
Sound-conducting media
Model of air molecule vibration (Time 1)
Model of air molecule vibration (Time 2)
Model of air molecule vibration (Time 3)
Model of air molecule vibration (Time 4)
Model of air molecule vibration (Time 5)
Model of air molecule vibration
Wave action of molecular motion
Amplitude waveform
Amplitude waveform (2)
Where is pressure in this model
Pressure waveform
Measuring Sound
Measuring Sound Signal Amplitude
Measuring Sound Signal Amplitude (2)
What units do we use to measure signal amplitude
Brief Review The decibel scale
Absolute vs relative measurement
Typical reference values
Howeverhellip
Linear vs logarithmic
Linear vs logarithmic (2)
Logarithmic Scale
Logarithmic Scale (2)
Combining the idea of logarithmic and relativehellip
Intensity vs Pressure
Extending the formula to pressure
Measuring Sound Frequencyperiod
Measuring Sound Frequencyperiod (2)
Phase Uniform Circular Motion
Initiating a sound waves that differ only in phase
Spatial variation in pressure wave
Spatial variation in pressure wave
Spatial variation in pressure wave (2)
Relation between frequency and wavelength
Learning Objectives
Graphic representation of sound
Same sound different graphs
Classification of sounds
Simple periodic sound
Simple periodic sound Graphic appearance
Complex periodic sounds
Complex periodic sounds Graphic appearance
Complex periodic sounds Graphic appearance (2)
Glottal Source
Amplitude vs Phase Spectrum
Amplitude vs Phase Spectrum (2)
(Complex) Aperiodic sounds
Aperiodic sounds Graphic appearance
Aperiodic sounds Graphic appearance (2)
Analysis of complex waves
Learning Objectives (2)
The ldquoenveloperdquo of a sound wave
Waveform envelope
Waveform envelope (2)
Spectrum envelope
Thought Question
Amplitude Spectrum Window Size
ldquoInstantaneousrdquo Amplitude Spectra
(Long Term) Average Amplitude Spectrum
Slide 90
Learning Objectives (3)
The Spectrogram
Building a spectrogram
Building a spectrogram
Building a spectrogram (2)
Two main types of spectrograms
Wide vs Narrow Band Spectrograms
Learning Objectives (4)
What is an ldquoAcousticrdquo Filter
Why might we be interested in filters
Kinds of frequency selective filters
Low Pass Filters
High Pass Filters
Band Pass Filter
Frequency Response Curve (FRC)
Operation of a filter on a signal
Learning Objectives (5)
Free vibration
Forced vibration
Forced vibration (2)
Resonance refers to
Back to the mass spring model
Acoustic Resonance
Acoustic Resonance (2)
Helmholtz Resonator
Actions of a Helmholtz Resonator
Other Acoustic Resonators Tube Resonators
Uniform tube closed at one end
Uniform tube closed at one end (2)
Uniform tube closed at one end
Comparing Helmholtz and tube resonators
Slide 122
Slide 123
Topic 3 A Brief Review of Physical Acoustics
Learning Objectivesbull Outline the physical processes underlying simple harmonic motion using the
mass-spring modelbull Describe the molecular basis of sound wave propagationbull Define the key characteristics of sinusoidal motion including
ndash Amplitude instantaneous peak peak-to-peak root-mean-square (RMS) the decibel scale
ndash Frequencyperiod including units of measurendash Phasendash Wavelength
bull Briefly describe the relation between the sine wave and uniform circular motion
bull Outline the relationship between the frequency and wavelength of a sound wave
Spring Mass Model
bull Mass (inertia)ndash Newtonrsquos first law of motionndash Opposition to
accelerationdecelerationbull Elasticityndash Opposition to displacementndash Rest positionndash Recoil force
bull Complex gt one frequency componentbull Aperiodic Does not repeat itselfbull Frequency components are not systematically
relatedbull May be ndash Continuousndash Transient
Aperiodic sounds Graphic appearance
bull Time domainndash no repeating pattern of pressure change
bull Frequency domainndash the spectrum is dense ndash No ldquopicket fencerdquo
bull Auditory impression sounds lsquonoisyrsquo
Aperiodic sounds Graphic appearance
From Hillenbrand
>
Analysis of complex wavesbull Waves can be summedbull Complex waves are the sum of simple wavesbull Fourier French Mathematician
ndash Any complex waveform may be formed by summing sinusoids of various frequency amplitude and phase
bull Fourier Analysisndash Provides a unique (only one) solution for a given sound signalndash Is reflected in the amplitude and phase spectrum of the signalndash Reveals the building blocks of complex waves which are sinusoids
Learning Objectives
bull Draw and differentiate the waveform and the waveform envelope
bull Draw and differentiate the amplitude spectrum the phase spectrum and the spectrum envelope
bull Differential between short-term spectra and long-term average spectra
The ldquoenveloperdquo of a sound wave
bull Waveform envelopendash imaginary smooth line that follows the peak of the
amplitude of a sound pressure waveformbull Spectrum envelopendash Imaginary smooth line drawn on top of the
amplitude spectrum
Waveform envelope
From Hillenbrand
Waveform envelope
Time
>
Spectrum envelope
Frequency
Ampl
itude
Thought Question
Can an aperiodic and complex periodic sound have identical
spectrum envelopes
Amplitude Spectrum Window Size
bull ldquoshort-termrdquo vs ldquolong-term averagerdquo amplitude spectrum
ldquoInstantaneousrdquo Amplitude Spectra
(Long Term) Average Amplitude Spectrum
Learning Objectivesbull Describe how the amplitude spectrum and the spectrogram are
relatedbull Identify the axis units of the spectrogrambull Provide some advantages of the spectrogram over the
amplitude spectrumbull Distinguish between a wide band and narrow band spectrogram
and outline the different information each providesbull Distinguish between a harmonic and a formant on a
spectrogrambull Be able to draw stylized (highly simplified) spectrograms based
on spectra and spectrum envelopes
The Spectrogram
Rotate90 degrees
F
AF
A
Building a spectrogram
Rotate it so thatThe amplitude isComing out of thepage
F
A This is really narrow because it is a slice in time
F
Time
Building a spectrogram
Dark bands= amplitudePeaks
Time
Freq
uenc
y
Building a spectrogram
Two main types of spectrograms
bull Narrow-band spectrogramsndash Akin to amplitude spectrums ldquolined uprdquondash Frequency resolution is really sharp
bull Wide-band spectrogramsndash Akin to spectrum envelopes ldquolined uprdquondash Frequency resolution not so sharp
Highlights harmonic structure
Highlights spectrum envelope
Wide vs Narrow Band Spectrograms
Learning Objectives
bull Define an acoustic filterbull Draw and label a frequency response curvebull Draw and differentiate different types of acoustic
filtersbull Define terms such as cutoff frequency center
frequency roll off rate gain and bandwidthbull Define and draw a basic filter system and relate that
to the source-filter theory of speech production
What is an ldquoAcousticrdquo Filter
bull holds back (attenuates) certain sounds and lets other sounds through - selective
Why might we be interested in filters
bull Human vocal tract acts like a frequency selective acoustic filter
bull Human auditory system behaves as a frequency selective filter
bull helps us understand how speech is produced and perceived
Kinds of frequency selective filters
Low-pass filtersndash Lets low frequencies ldquopass throughrdquo and attenuates high
frequencies
High-pass filtersndash Lets high frequencies ldquopass throughrdquo and attenuates low
frequencies
Band-pass filtersndash Lets a particular frequency range ldquopass throughrdquo and
attenuates other frequencies
Low Pass Filters
Frequencylow high
Gai
n
+
-
High Pass Filters
Frequencylow high
Gai
n
+
-
Band Pass Filter
Frequencylow high
Gai
n
+
-
Frequency Response Curve (FRC)
Frequencylow high
Gai
n
+
-
Center frequency
lower cutofffrequency
upper cutoff frequency
passband
3 dB
Operation of a filter on a signal
NOTE Amplitude spectrum describes a soundFrequency response curve describes a filter
Learning Objectivesbull Define resonance free and forced vibrationbull Describe how the pendulum and spring mass models can
help explain resonancebull Outline how mass and stiffness influences the resonant
frequency of a mass spring systembull Outline how acoustic resonators behave like acoustic filtersbull Calculate resonant frequencies of a uniform tube based on
its physical dimensionsbull Describe how the wavelength of the sound determines the
resonant frequency of tube
Free vibration
bull objects tend to vibrate at a characteristic or resonant frequency (RF)
Forced vibration
bull A vibrating system can force a nearby system into vibration
bull The efficiency with which this is accomplished is related to the similarity in the resonant frequency (RF) of the two systems
Forced vibration
bull If the RF of the two systems are the same the amplitude of forced vibration will be large
bull If the RF of the two systems are quite different the amplitude of forced vibration will be small or nonexistent
Resonance refers to
bull The tendency for an object to vibrate at a particular frequency or frequencies
bull The ability of a vibrating system to force another system into vibration
Back to the mass spring model
bull Vibratory frequency of the mass spring determined byndash Massndash Stiffness of the spring
httpphetcoloradoeduensimulationmass-spring-lab
Acoustic Resonance
bull Ideas from mechanical resonance also applies to acoustic systems
bull Acoustic chambers will transmit sound frequencies with more or less efficiency depending upon the physical characteristics
bull Therefore they act as filters passing through (and even amplifying) some frequencies and attentuating others
Acoustic Resonance
bull And since they act as filters they have most of the same features of a filter even though we might use different names
bull Center frequency is often termed the resonant frequency
bull Frequency response curve often termed the resonance curve
Helmholtz Resonator
Actions of a Helmholtz Resonator
Stephen M Tasko
Other Acoustic Resonators Tube Resonators
bull Uniform tubes Factors that influence resonancendash Lengthndash Cross-sectional area along its lengthndash Whether it is closed at either or both ends
Uniform tube closed at one end
Uniform tube closed at one end
Stephen M Tasko
Uniform tube closed at one end
First resonance or formant
F1 = c4lWhere
c=speed of sound (35000 cmsec)l = length of the tube
males ~ 175 cmfemales ~ 14 cm
Higher resonantformant frequencies are odd multiples of F1
For examplebull F1 = (c4l )1
bull F2 = (c4l )3
bull F3 = (c4l )5
Comparing Helmholtz and tube resonators
Resonator Features
Sharply tuned Broadly tuned
Resonator Features
An example of the resonance characteristics of the human vocal tract
Frequency
Gain
SPPA 4030 Speech Science
Topic 1 The Speech Chain
The Speech Chain (Denes amp Pinson 1993)
What information is embedded in the speech signal
Branches of science employed to understand speech communication
Physical Quantities Review An Independent Learning Activity
Assignment 1
Topic 2 The Source-Filter Theory of Speech Production An Intr
Producing Speech
Source-Filter Theory of Speech Production
Vocal tract is a tube that can vary its shape
Source Filter Theory
Same Source Different Filter
Different Source Same Filters
Different Source Same Filters (Human)
Different Source Same Filters (Human) (2)
Different Source Same Filters (Human) (3)
Different Source Same Filters (Human) (4)
Different Source Same Filters (Non-Human)
Different Source Same Filters (Non-Human) (2)
Different Source Same Filters (Non-Human) If it quacks like a
Source Filter Theory Applied Alaryngeal Speech
Source-Filter Theory Applied Esophageal Insufflation Test
Source-Filter Theory Applied Tracheoesophageal (TE) Speech
Source Filter Theory Applied The Talkbox
Source-Filter Theory Applied The Talkbox
Topic 3 A Brief Review of Physical Acoustics
Spring Mass Model
What is sound
Sound-conducting media
Model of air molecule vibration (Time 1)
Model of air molecule vibration (Time 2)
Model of air molecule vibration (Time 3)
Model of air molecule vibration (Time 4)
Model of air molecule vibration (Time 5)
Model of air molecule vibration
Wave action of molecular motion
Amplitude waveform
Amplitude waveform (2)
Where is pressure in this model
Pressure waveform
Measuring Sound
Measuring Sound Signal Amplitude
Measuring Sound Signal Amplitude (2)
What units do we use to measure signal amplitude
Brief Review The decibel scale
Absolute vs relative measurement
Typical reference values
Howeverhellip
Linear vs logarithmic
Linear vs logarithmic (2)
Logarithmic Scale
Logarithmic Scale (2)
Combining the idea of logarithmic and relativehellip
Intensity vs Pressure
Extending the formula to pressure
Measuring Sound Frequencyperiod
Measuring Sound Frequencyperiod (2)
Phase Uniform Circular Motion
Initiating a sound waves that differ only in phase
Spatial variation in pressure wave
Spatial variation in pressure wave
Spatial variation in pressure wave (2)
Relation between frequency and wavelength
Learning Objectives
Graphic representation of sound
Same sound different graphs
Classification of sounds
Simple periodic sound
Simple periodic sound Graphic appearance
Complex periodic sounds
Complex periodic sounds Graphic appearance
Complex periodic sounds Graphic appearance (2)
Glottal Source
Amplitude vs Phase Spectrum
Amplitude vs Phase Spectrum (2)
(Complex) Aperiodic sounds
Aperiodic sounds Graphic appearance
Aperiodic sounds Graphic appearance (2)
Analysis of complex waves
Learning Objectives (2)
The ldquoenveloperdquo of a sound wave
Waveform envelope
Waveform envelope (2)
Spectrum envelope
Thought Question
Amplitude Spectrum Window Size
ldquoInstantaneousrdquo Amplitude Spectra
(Long Term) Average Amplitude Spectrum
Slide 90
Learning Objectives (3)
The Spectrogram
Building a spectrogram
Building a spectrogram
Building a spectrogram (2)
Two main types of spectrograms
Wide vs Narrow Band Spectrograms
Learning Objectives (4)
What is an ldquoAcousticrdquo Filter
Why might we be interested in filters
Kinds of frequency selective filters
Low Pass Filters
High Pass Filters
Band Pass Filter
Frequency Response Curve (FRC)
Operation of a filter on a signal
Learning Objectives (5)
Free vibration
Forced vibration
Forced vibration (2)
Resonance refers to
Back to the mass spring model
Acoustic Resonance
Acoustic Resonance (2)
Helmholtz Resonator
Actions of a Helmholtz Resonator
Other Acoustic Resonators Tube Resonators
Uniform tube closed at one end
Uniform tube closed at one end (2)
Uniform tube closed at one end
Comparing Helmholtz and tube resonators
Slide 122
Slide 123
Spring Mass Model
bull Mass (inertia)ndash Newtonrsquos first law of motionndash Opposition to
accelerationdecelerationbull Elasticityndash Opposition to displacementndash Rest positionndash Recoil force
bull Complex gt one frequency componentbull Aperiodic Does not repeat itselfbull Frequency components are not systematically
relatedbull May be ndash Continuousndash Transient
Aperiodic sounds Graphic appearance
bull Time domainndash no repeating pattern of pressure change
bull Frequency domainndash the spectrum is dense ndash No ldquopicket fencerdquo
bull Auditory impression sounds lsquonoisyrsquo
Aperiodic sounds Graphic appearance
From Hillenbrand
>
Analysis of complex wavesbull Waves can be summedbull Complex waves are the sum of simple wavesbull Fourier French Mathematician
ndash Any complex waveform may be formed by summing sinusoids of various frequency amplitude and phase
bull Fourier Analysisndash Provides a unique (only one) solution for a given sound signalndash Is reflected in the amplitude and phase spectrum of the signalndash Reveals the building blocks of complex waves which are sinusoids
Learning Objectives
bull Draw and differentiate the waveform and the waveform envelope
bull Draw and differentiate the amplitude spectrum the phase spectrum and the spectrum envelope
bull Differential between short-term spectra and long-term average spectra
The ldquoenveloperdquo of a sound wave
bull Waveform envelopendash imaginary smooth line that follows the peak of the
amplitude of a sound pressure waveformbull Spectrum envelopendash Imaginary smooth line drawn on top of the
amplitude spectrum
Waveform envelope
From Hillenbrand
Waveform envelope
Time
>
Spectrum envelope
Frequency
Ampl
itude
Thought Question
Can an aperiodic and complex periodic sound have identical
spectrum envelopes
Amplitude Spectrum Window Size
bull ldquoshort-termrdquo vs ldquolong-term averagerdquo amplitude spectrum
ldquoInstantaneousrdquo Amplitude Spectra
(Long Term) Average Amplitude Spectrum
Learning Objectivesbull Describe how the amplitude spectrum and the spectrogram are
relatedbull Identify the axis units of the spectrogrambull Provide some advantages of the spectrogram over the
amplitude spectrumbull Distinguish between a wide band and narrow band spectrogram
and outline the different information each providesbull Distinguish between a harmonic and a formant on a
spectrogrambull Be able to draw stylized (highly simplified) spectrograms based
on spectra and spectrum envelopes
The Spectrogram
Rotate90 degrees
F
AF
A
Building a spectrogram
Rotate it so thatThe amplitude isComing out of thepage
F
A This is really narrow because it is a slice in time
F
Time
Building a spectrogram
Dark bands= amplitudePeaks
Time
Freq
uenc
y
Building a spectrogram
Two main types of spectrograms
bull Narrow-band spectrogramsndash Akin to amplitude spectrums ldquolined uprdquondash Frequency resolution is really sharp
bull Wide-band spectrogramsndash Akin to spectrum envelopes ldquolined uprdquondash Frequency resolution not so sharp
Highlights harmonic structure
Highlights spectrum envelope
Wide vs Narrow Band Spectrograms
Learning Objectives
bull Define an acoustic filterbull Draw and label a frequency response curvebull Draw and differentiate different types of acoustic
filtersbull Define terms such as cutoff frequency center
frequency roll off rate gain and bandwidthbull Define and draw a basic filter system and relate that
to the source-filter theory of speech production
What is an ldquoAcousticrdquo Filter
bull holds back (attenuates) certain sounds and lets other sounds through - selective
Why might we be interested in filters
bull Human vocal tract acts like a frequency selective acoustic filter
bull Human auditory system behaves as a frequency selective filter
bull helps us understand how speech is produced and perceived
Kinds of frequency selective filters
Low-pass filtersndash Lets low frequencies ldquopass throughrdquo and attenuates high
frequencies
High-pass filtersndash Lets high frequencies ldquopass throughrdquo and attenuates low
frequencies
Band-pass filtersndash Lets a particular frequency range ldquopass throughrdquo and
attenuates other frequencies
Low Pass Filters
Frequencylow high
Gai
n
+
-
High Pass Filters
Frequencylow high
Gai
n
+
-
Band Pass Filter
Frequencylow high
Gai
n
+
-
Frequency Response Curve (FRC)
Frequencylow high
Gai
n
+
-
Center frequency
lower cutofffrequency
upper cutoff frequency
passband
3 dB
Operation of a filter on a signal
NOTE Amplitude spectrum describes a soundFrequency response curve describes a filter
Learning Objectivesbull Define resonance free and forced vibrationbull Describe how the pendulum and spring mass models can
help explain resonancebull Outline how mass and stiffness influences the resonant
frequency of a mass spring systembull Outline how acoustic resonators behave like acoustic filtersbull Calculate resonant frequencies of a uniform tube based on
its physical dimensionsbull Describe how the wavelength of the sound determines the
resonant frequency of tube
Free vibration
bull objects tend to vibrate at a characteristic or resonant frequency (RF)
Forced vibration
bull A vibrating system can force a nearby system into vibration
bull The efficiency with which this is accomplished is related to the similarity in the resonant frequency (RF) of the two systems
Forced vibration
bull If the RF of the two systems are the same the amplitude of forced vibration will be large
bull If the RF of the two systems are quite different the amplitude of forced vibration will be small or nonexistent
Resonance refers to
bull The tendency for an object to vibrate at a particular frequency or frequencies
bull The ability of a vibrating system to force another system into vibration
Back to the mass spring model
bull Vibratory frequency of the mass spring determined byndash Massndash Stiffness of the spring
httpphetcoloradoeduensimulationmass-spring-lab
Acoustic Resonance
bull Ideas from mechanical resonance also applies to acoustic systems
bull Acoustic chambers will transmit sound frequencies with more or less efficiency depending upon the physical characteristics
bull Therefore they act as filters passing through (and even amplifying) some frequencies and attentuating others
Acoustic Resonance
bull And since they act as filters they have most of the same features of a filter even though we might use different names
bull Center frequency is often termed the resonant frequency
bull Frequency response curve often termed the resonance curve
Helmholtz Resonator
Actions of a Helmholtz Resonator
Stephen M Tasko
Other Acoustic Resonators Tube Resonators
bull Uniform tubes Factors that influence resonancendash Lengthndash Cross-sectional area along its lengthndash Whether it is closed at either or both ends
Uniform tube closed at one end
Uniform tube closed at one end
Stephen M Tasko
Uniform tube closed at one end
First resonance or formant
F1 = c4lWhere
c=speed of sound (35000 cmsec)l = length of the tube
males ~ 175 cmfemales ~ 14 cm
Higher resonantformant frequencies are odd multiples of F1
For examplebull F1 = (c4l )1
bull F2 = (c4l )3
bull F3 = (c4l )5
Comparing Helmholtz and tube resonators
Resonator Features
Sharply tuned Broadly tuned
Resonator Features
An example of the resonance characteristics of the human vocal tract
Frequency
Gain
SPPA 4030 Speech Science
Topic 1 The Speech Chain
The Speech Chain (Denes amp Pinson 1993)
What information is embedded in the speech signal
Branches of science employed to understand speech communication
Physical Quantities Review An Independent Learning Activity
Assignment 1
Topic 2 The Source-Filter Theory of Speech Production An Intr
Producing Speech
Source-Filter Theory of Speech Production
Vocal tract is a tube that can vary its shape
Source Filter Theory
Same Source Different Filter
Different Source Same Filters
Different Source Same Filters (Human)
Different Source Same Filters (Human) (2)
Different Source Same Filters (Human) (3)
Different Source Same Filters (Human) (4)
Different Source Same Filters (Non-Human)
Different Source Same Filters (Non-Human) (2)
Different Source Same Filters (Non-Human) If it quacks like a
Source Filter Theory Applied Alaryngeal Speech
Source-Filter Theory Applied Esophageal Insufflation Test
Source-Filter Theory Applied Tracheoesophageal (TE) Speech
Source Filter Theory Applied The Talkbox
Source-Filter Theory Applied The Talkbox
Topic 3 A Brief Review of Physical Acoustics
Spring Mass Model
What is sound
Sound-conducting media
Model of air molecule vibration (Time 1)
Model of air molecule vibration (Time 2)
Model of air molecule vibration (Time 3)
Model of air molecule vibration (Time 4)
Model of air molecule vibration (Time 5)
Model of air molecule vibration
Wave action of molecular motion
Amplitude waveform
Amplitude waveform (2)
Where is pressure in this model
Pressure waveform
Measuring Sound
Measuring Sound Signal Amplitude
Measuring Sound Signal Amplitude (2)
What units do we use to measure signal amplitude
Brief Review The decibel scale
Absolute vs relative measurement
Typical reference values
Howeverhellip
Linear vs logarithmic
Linear vs logarithmic (2)
Logarithmic Scale
Logarithmic Scale (2)
Combining the idea of logarithmic and relativehellip
Intensity vs Pressure
Extending the formula to pressure
Measuring Sound Frequencyperiod
Measuring Sound Frequencyperiod (2)
Phase Uniform Circular Motion
Initiating a sound waves that differ only in phase
Spatial variation in pressure wave
Spatial variation in pressure wave
Spatial variation in pressure wave (2)
Relation between frequency and wavelength
Learning Objectives
Graphic representation of sound
Same sound different graphs
Classification of sounds
Simple periodic sound
Simple periodic sound Graphic appearance
Complex periodic sounds
Complex periodic sounds Graphic appearance
Complex periodic sounds Graphic appearance (2)
Glottal Source
Amplitude vs Phase Spectrum
Amplitude vs Phase Spectrum (2)
(Complex) Aperiodic sounds
Aperiodic sounds Graphic appearance
Aperiodic sounds Graphic appearance (2)
Analysis of complex waves
Learning Objectives (2)
The ldquoenveloperdquo of a sound wave
Waveform envelope
Waveform envelope (2)
Spectrum envelope
Thought Question
Amplitude Spectrum Window Size
ldquoInstantaneousrdquo Amplitude Spectra
(Long Term) Average Amplitude Spectrum
Slide 90
Learning Objectives (3)
The Spectrogram
Building a spectrogram
Building a spectrogram
Building a spectrogram (2)
Two main types of spectrograms
Wide vs Narrow Band Spectrograms
Learning Objectives (4)
What is an ldquoAcousticrdquo Filter
Why might we be interested in filters
Kinds of frequency selective filters
Low Pass Filters
High Pass Filters
Band Pass Filter
Frequency Response Curve (FRC)
Operation of a filter on a signal
Learning Objectives (5)
Free vibration
Forced vibration
Forced vibration (2)
Resonance refers to
Back to the mass spring model
Acoustic Resonance
Acoustic Resonance (2)
Helmholtz Resonator
Actions of a Helmholtz Resonator
Other Acoustic Resonators Tube Resonators
Uniform tube closed at one end
Uniform tube closed at one end (2)
Uniform tube closed at one end
Comparing Helmholtz and tube resonators
Slide 122
Slide 123
What is sound
bull It may be defined as the propagation of a pressure wave in space and time
bull Complex gt one frequency componentbull Aperiodic Does not repeat itselfbull Frequency components are not systematically
relatedbull May be ndash Continuousndash Transient
Aperiodic sounds Graphic appearance
bull Time domainndash no repeating pattern of pressure change
bull Frequency domainndash the spectrum is dense ndash No ldquopicket fencerdquo
bull Auditory impression sounds lsquonoisyrsquo
Aperiodic sounds Graphic appearance
From Hillenbrand
>
Analysis of complex wavesbull Waves can be summedbull Complex waves are the sum of simple wavesbull Fourier French Mathematician
ndash Any complex waveform may be formed by summing sinusoids of various frequency amplitude and phase
bull Fourier Analysisndash Provides a unique (only one) solution for a given sound signalndash Is reflected in the amplitude and phase spectrum of the signalndash Reveals the building blocks of complex waves which are sinusoids
Learning Objectives
bull Draw and differentiate the waveform and the waveform envelope
bull Draw and differentiate the amplitude spectrum the phase spectrum and the spectrum envelope
bull Differential between short-term spectra and long-term average spectra
The ldquoenveloperdquo of a sound wave
bull Waveform envelopendash imaginary smooth line that follows the peak of the
amplitude of a sound pressure waveformbull Spectrum envelopendash Imaginary smooth line drawn on top of the
amplitude spectrum
Waveform envelope
From Hillenbrand
Waveform envelope
Time
>
Spectrum envelope
Frequency
Ampl
itude
Thought Question
Can an aperiodic and complex periodic sound have identical
spectrum envelopes
Amplitude Spectrum Window Size
bull ldquoshort-termrdquo vs ldquolong-term averagerdquo amplitude spectrum
ldquoInstantaneousrdquo Amplitude Spectra
(Long Term) Average Amplitude Spectrum
Learning Objectivesbull Describe how the amplitude spectrum and the spectrogram are
relatedbull Identify the axis units of the spectrogrambull Provide some advantages of the spectrogram over the
amplitude spectrumbull Distinguish between a wide band and narrow band spectrogram
and outline the different information each providesbull Distinguish between a harmonic and a formant on a
spectrogrambull Be able to draw stylized (highly simplified) spectrograms based
on spectra and spectrum envelopes
The Spectrogram
Rotate90 degrees
F
AF
A
Building a spectrogram
Rotate it so thatThe amplitude isComing out of thepage
F
A This is really narrow because it is a slice in time
F
Time
Building a spectrogram
Dark bands= amplitudePeaks
Time
Freq
uenc
y
Building a spectrogram
Two main types of spectrograms
bull Narrow-band spectrogramsndash Akin to amplitude spectrums ldquolined uprdquondash Frequency resolution is really sharp
bull Wide-band spectrogramsndash Akin to spectrum envelopes ldquolined uprdquondash Frequency resolution not so sharp
Highlights harmonic structure
Highlights spectrum envelope
Wide vs Narrow Band Spectrograms
Learning Objectives
bull Define an acoustic filterbull Draw and label a frequency response curvebull Draw and differentiate different types of acoustic
filtersbull Define terms such as cutoff frequency center
frequency roll off rate gain and bandwidthbull Define and draw a basic filter system and relate that
to the source-filter theory of speech production
What is an ldquoAcousticrdquo Filter
bull holds back (attenuates) certain sounds and lets other sounds through - selective
Why might we be interested in filters
bull Human vocal tract acts like a frequency selective acoustic filter
bull Human auditory system behaves as a frequency selective filter
bull helps us understand how speech is produced and perceived
Kinds of frequency selective filters
Low-pass filtersndash Lets low frequencies ldquopass throughrdquo and attenuates high
frequencies
High-pass filtersndash Lets high frequencies ldquopass throughrdquo and attenuates low
frequencies
Band-pass filtersndash Lets a particular frequency range ldquopass throughrdquo and
attenuates other frequencies
Low Pass Filters
Frequencylow high
Gai
n
+
-
High Pass Filters
Frequencylow high
Gai
n
+
-
Band Pass Filter
Frequencylow high
Gai
n
+
-
Frequency Response Curve (FRC)
Frequencylow high
Gai
n
+
-
Center frequency
lower cutofffrequency
upper cutoff frequency
passband
3 dB
Operation of a filter on a signal
NOTE Amplitude spectrum describes a soundFrequency response curve describes a filter
Learning Objectivesbull Define resonance free and forced vibrationbull Describe how the pendulum and spring mass models can
help explain resonancebull Outline how mass and stiffness influences the resonant
frequency of a mass spring systembull Outline how acoustic resonators behave like acoustic filtersbull Calculate resonant frequencies of a uniform tube based on
its physical dimensionsbull Describe how the wavelength of the sound determines the
resonant frequency of tube
Free vibration
bull objects tend to vibrate at a characteristic or resonant frequency (RF)
Forced vibration
bull A vibrating system can force a nearby system into vibration
bull The efficiency with which this is accomplished is related to the similarity in the resonant frequency (RF) of the two systems
Forced vibration
bull If the RF of the two systems are the same the amplitude of forced vibration will be large
bull If the RF of the two systems are quite different the amplitude of forced vibration will be small or nonexistent
Resonance refers to
bull The tendency for an object to vibrate at a particular frequency or frequencies
bull The ability of a vibrating system to force another system into vibration
Back to the mass spring model
bull Vibratory frequency of the mass spring determined byndash Massndash Stiffness of the spring
httpphetcoloradoeduensimulationmass-spring-lab
Acoustic Resonance
bull Ideas from mechanical resonance also applies to acoustic systems
bull Acoustic chambers will transmit sound frequencies with more or less efficiency depending upon the physical characteristics
bull Therefore they act as filters passing through (and even amplifying) some frequencies and attentuating others
Acoustic Resonance
bull And since they act as filters they have most of the same features of a filter even though we might use different names
bull Center frequency is often termed the resonant frequency
bull Frequency response curve often termed the resonance curve
Helmholtz Resonator
Actions of a Helmholtz Resonator
Stephen M Tasko
Other Acoustic Resonators Tube Resonators
bull Uniform tubes Factors that influence resonancendash Lengthndash Cross-sectional area along its lengthndash Whether it is closed at either or both ends
Uniform tube closed at one end
Uniform tube closed at one end
Stephen M Tasko
Uniform tube closed at one end
First resonance or formant
F1 = c4lWhere
c=speed of sound (35000 cmsec)l = length of the tube
males ~ 175 cmfemales ~ 14 cm
Higher resonantformant frequencies are odd multiples of F1
For examplebull F1 = (c4l )1
bull F2 = (c4l )3
bull F3 = (c4l )5
Comparing Helmholtz and tube resonators
Resonator Features
Sharply tuned Broadly tuned
Resonator Features
An example of the resonance characteristics of the human vocal tract
Frequency
Gain
SPPA 4030 Speech Science
Topic 1 The Speech Chain
The Speech Chain (Denes amp Pinson 1993)
What information is embedded in the speech signal
Branches of science employed to understand speech communication
Physical Quantities Review An Independent Learning Activity
Assignment 1
Topic 2 The Source-Filter Theory of Speech Production An Intr
Producing Speech
Source-Filter Theory of Speech Production
Vocal tract is a tube that can vary its shape
Source Filter Theory
Same Source Different Filter
Different Source Same Filters
Different Source Same Filters (Human)
Different Source Same Filters (Human) (2)
Different Source Same Filters (Human) (3)
Different Source Same Filters (Human) (4)
Different Source Same Filters (Non-Human)
Different Source Same Filters (Non-Human) (2)
Different Source Same Filters (Non-Human) If it quacks like a
Source Filter Theory Applied Alaryngeal Speech
Source-Filter Theory Applied Esophageal Insufflation Test
Source-Filter Theory Applied Tracheoesophageal (TE) Speech
Source Filter Theory Applied The Talkbox
Source-Filter Theory Applied The Talkbox
Topic 3 A Brief Review of Physical Acoustics
Spring Mass Model
What is sound
Sound-conducting media
Model of air molecule vibration (Time 1)
Model of air molecule vibration (Time 2)
Model of air molecule vibration (Time 3)
Model of air molecule vibration (Time 4)
Model of air molecule vibration (Time 5)
Model of air molecule vibration
Wave action of molecular motion
Amplitude waveform
Amplitude waveform (2)
Where is pressure in this model
Pressure waveform
Measuring Sound
Measuring Sound Signal Amplitude
Measuring Sound Signal Amplitude (2)
What units do we use to measure signal amplitude
Brief Review The decibel scale
Absolute vs relative measurement
Typical reference values
Howeverhellip
Linear vs logarithmic
Linear vs logarithmic (2)
Logarithmic Scale
Logarithmic Scale (2)
Combining the idea of logarithmic and relativehellip
Intensity vs Pressure
Extending the formula to pressure
Measuring Sound Frequencyperiod
Measuring Sound Frequencyperiod (2)
Phase Uniform Circular Motion
Initiating a sound waves that differ only in phase
bull Complex gt one frequency componentbull Aperiodic Does not repeat itselfbull Frequency components are not systematically
relatedbull May be ndash Continuousndash Transient
Aperiodic sounds Graphic appearance
bull Time domainndash no repeating pattern of pressure change
bull Frequency domainndash the spectrum is dense ndash No ldquopicket fencerdquo
bull Auditory impression sounds lsquonoisyrsquo
Aperiodic sounds Graphic appearance
From Hillenbrand
>
Analysis of complex wavesbull Waves can be summedbull Complex waves are the sum of simple wavesbull Fourier French Mathematician
ndash Any complex waveform may be formed by summing sinusoids of various frequency amplitude and phase
bull Fourier Analysisndash Provides a unique (only one) solution for a given sound signalndash Is reflected in the amplitude and phase spectrum of the signalndash Reveals the building blocks of complex waves which are sinusoids
Learning Objectives
bull Draw and differentiate the waveform and the waveform envelope
bull Draw and differentiate the amplitude spectrum the phase spectrum and the spectrum envelope
bull Differential between short-term spectra and long-term average spectra
The ldquoenveloperdquo of a sound wave
bull Waveform envelopendash imaginary smooth line that follows the peak of the
amplitude of a sound pressure waveformbull Spectrum envelopendash Imaginary smooth line drawn on top of the
amplitude spectrum
Waveform envelope
From Hillenbrand
Waveform envelope
Time
>
Spectrum envelope
Frequency
Ampl
itude
Thought Question
Can an aperiodic and complex periodic sound have identical
spectrum envelopes
Amplitude Spectrum Window Size
bull ldquoshort-termrdquo vs ldquolong-term averagerdquo amplitude spectrum
ldquoInstantaneousrdquo Amplitude Spectra
(Long Term) Average Amplitude Spectrum
Learning Objectivesbull Describe how the amplitude spectrum and the spectrogram are
relatedbull Identify the axis units of the spectrogrambull Provide some advantages of the spectrogram over the
amplitude spectrumbull Distinguish between a wide band and narrow band spectrogram
and outline the different information each providesbull Distinguish between a harmonic and a formant on a
spectrogrambull Be able to draw stylized (highly simplified) spectrograms based
on spectra and spectrum envelopes
The Spectrogram
Rotate90 degrees
F
AF
A
Building a spectrogram
Rotate it so thatThe amplitude isComing out of thepage
F
A This is really narrow because it is a slice in time
F
Time
Building a spectrogram
Dark bands= amplitudePeaks
Time
Freq
uenc
y
Building a spectrogram
Two main types of spectrograms
bull Narrow-band spectrogramsndash Akin to amplitude spectrums ldquolined uprdquondash Frequency resolution is really sharp
bull Wide-band spectrogramsndash Akin to spectrum envelopes ldquolined uprdquondash Frequency resolution not so sharp
Highlights harmonic structure
Highlights spectrum envelope
Wide vs Narrow Band Spectrograms
Learning Objectives
bull Define an acoustic filterbull Draw and label a frequency response curvebull Draw and differentiate different types of acoustic
filtersbull Define terms such as cutoff frequency center
frequency roll off rate gain and bandwidthbull Define and draw a basic filter system and relate that
to the source-filter theory of speech production
What is an ldquoAcousticrdquo Filter
bull holds back (attenuates) certain sounds and lets other sounds through - selective
Why might we be interested in filters
bull Human vocal tract acts like a frequency selective acoustic filter
bull Human auditory system behaves as a frequency selective filter
bull helps us understand how speech is produced and perceived
Kinds of frequency selective filters
Low-pass filtersndash Lets low frequencies ldquopass throughrdquo and attenuates high
frequencies
High-pass filtersndash Lets high frequencies ldquopass throughrdquo and attenuates low
frequencies
Band-pass filtersndash Lets a particular frequency range ldquopass throughrdquo and
attenuates other frequencies
Low Pass Filters
Frequencylow high
Gai
n
+
-
High Pass Filters
Frequencylow high
Gai
n
+
-
Band Pass Filter
Frequencylow high
Gai
n
+
-
Frequency Response Curve (FRC)
Frequencylow high
Gai
n
+
-
Center frequency
lower cutofffrequency
upper cutoff frequency
passband
3 dB
Operation of a filter on a signal
NOTE Amplitude spectrum describes a soundFrequency response curve describes a filter
Learning Objectivesbull Define resonance free and forced vibrationbull Describe how the pendulum and spring mass models can
help explain resonancebull Outline how mass and stiffness influences the resonant
frequency of a mass spring systembull Outline how acoustic resonators behave like acoustic filtersbull Calculate resonant frequencies of a uniform tube based on
its physical dimensionsbull Describe how the wavelength of the sound determines the
resonant frequency of tube
Free vibration
bull objects tend to vibrate at a characteristic or resonant frequency (RF)
Forced vibration
bull A vibrating system can force a nearby system into vibration
bull The efficiency with which this is accomplished is related to the similarity in the resonant frequency (RF) of the two systems
Forced vibration
bull If the RF of the two systems are the same the amplitude of forced vibration will be large
bull If the RF of the two systems are quite different the amplitude of forced vibration will be small or nonexistent
Resonance refers to
bull The tendency for an object to vibrate at a particular frequency or frequencies
bull The ability of a vibrating system to force another system into vibration
Back to the mass spring model
bull Vibratory frequency of the mass spring determined byndash Massndash Stiffness of the spring
httpphetcoloradoeduensimulationmass-spring-lab
Acoustic Resonance
bull Ideas from mechanical resonance also applies to acoustic systems
bull Acoustic chambers will transmit sound frequencies with more or less efficiency depending upon the physical characteristics
bull Therefore they act as filters passing through (and even amplifying) some frequencies and attentuating others
Acoustic Resonance
bull And since they act as filters they have most of the same features of a filter even though we might use different names
bull Center frequency is often termed the resonant frequency
bull Frequency response curve often termed the resonance curve
Helmholtz Resonator
Actions of a Helmholtz Resonator
Stephen M Tasko
Other Acoustic Resonators Tube Resonators
bull Uniform tubes Factors that influence resonancendash Lengthndash Cross-sectional area along its lengthndash Whether it is closed at either or both ends
Uniform tube closed at one end
Uniform tube closed at one end
Stephen M Tasko
Uniform tube closed at one end
First resonance or formant
F1 = c4lWhere
c=speed of sound (35000 cmsec)l = length of the tube
males ~ 175 cmfemales ~ 14 cm
Higher resonantformant frequencies are odd multiples of F1
For examplebull F1 = (c4l )1
bull F2 = (c4l )3
bull F3 = (c4l )5
Comparing Helmholtz and tube resonators
Resonator Features
Sharply tuned Broadly tuned
Resonator Features
An example of the resonance characteristics of the human vocal tract
Frequency
Gain
SPPA 4030 Speech Science
Topic 1 The Speech Chain
The Speech Chain (Denes amp Pinson 1993)
What information is embedded in the speech signal
Branches of science employed to understand speech communication
Physical Quantities Review An Independent Learning Activity
Assignment 1
Topic 2 The Source-Filter Theory of Speech Production An Intr
Producing Speech
Source-Filter Theory of Speech Production
Vocal tract is a tube that can vary its shape
Source Filter Theory
Same Source Different Filter
Different Source Same Filters
Different Source Same Filters (Human)
Different Source Same Filters (Human) (2)
Different Source Same Filters (Human) (3)
Different Source Same Filters (Human) (4)
Different Source Same Filters (Non-Human)
Different Source Same Filters (Non-Human) (2)
Different Source Same Filters (Non-Human) If it quacks like a
Source Filter Theory Applied Alaryngeal Speech
Source-Filter Theory Applied Esophageal Insufflation Test
Source-Filter Theory Applied Tracheoesophageal (TE) Speech
Source Filter Theory Applied The Talkbox
Source-Filter Theory Applied The Talkbox
Topic 3 A Brief Review of Physical Acoustics
Spring Mass Model
What is sound
Sound-conducting media
Model of air molecule vibration (Time 1)
Model of air molecule vibration (Time 2)
Model of air molecule vibration (Time 3)
Model of air molecule vibration (Time 4)
Model of air molecule vibration (Time 5)
Model of air molecule vibration
Wave action of molecular motion
Amplitude waveform
Amplitude waveform (2)
Where is pressure in this model
Pressure waveform
Measuring Sound
Measuring Sound Signal Amplitude
Measuring Sound Signal Amplitude (2)
What units do we use to measure signal amplitude
Brief Review The decibel scale
Absolute vs relative measurement
Typical reference values
Howeverhellip
Linear vs logarithmic
Linear vs logarithmic (2)
Logarithmic Scale
Logarithmic Scale (2)
Combining the idea of logarithmic and relativehellip
Intensity vs Pressure
Extending the formula to pressure
Measuring Sound Frequencyperiod
Measuring Sound Frequencyperiod (2)
Phase Uniform Circular Motion
Initiating a sound waves that differ only in phase
bull Complex gt one frequency componentbull Aperiodic Does not repeat itselfbull Frequency components are not systematically
relatedbull May be ndash Continuousndash Transient
Aperiodic sounds Graphic appearance
bull Time domainndash no repeating pattern of pressure change
bull Frequency domainndash the spectrum is dense ndash No ldquopicket fencerdquo
bull Auditory impression sounds lsquonoisyrsquo
Aperiodic sounds Graphic appearance
From Hillenbrand
>
Analysis of complex wavesbull Waves can be summedbull Complex waves are the sum of simple wavesbull Fourier French Mathematician
ndash Any complex waveform may be formed by summing sinusoids of various frequency amplitude and phase
bull Fourier Analysisndash Provides a unique (only one) solution for a given sound signalndash Is reflected in the amplitude and phase spectrum of the signalndash Reveals the building blocks of complex waves which are sinusoids
Learning Objectives
bull Draw and differentiate the waveform and the waveform envelope
bull Draw and differentiate the amplitude spectrum the phase spectrum and the spectrum envelope
bull Differential between short-term spectra and long-term average spectra
The ldquoenveloperdquo of a sound wave
bull Waveform envelopendash imaginary smooth line that follows the peak of the
amplitude of a sound pressure waveformbull Spectrum envelopendash Imaginary smooth line drawn on top of the
amplitude spectrum
Waveform envelope
From Hillenbrand
Waveform envelope
Time
>
Spectrum envelope
Frequency
Ampl
itude
Thought Question
Can an aperiodic and complex periodic sound have identical
spectrum envelopes
Amplitude Spectrum Window Size
bull ldquoshort-termrdquo vs ldquolong-term averagerdquo amplitude spectrum
ldquoInstantaneousrdquo Amplitude Spectra
(Long Term) Average Amplitude Spectrum
Learning Objectivesbull Describe how the amplitude spectrum and the spectrogram are
relatedbull Identify the axis units of the spectrogrambull Provide some advantages of the spectrogram over the
amplitude spectrumbull Distinguish between a wide band and narrow band spectrogram
and outline the different information each providesbull Distinguish between a harmonic and a formant on a
spectrogrambull Be able to draw stylized (highly simplified) spectrograms based
on spectra and spectrum envelopes
The Spectrogram
Rotate90 degrees
F
AF
A
Building a spectrogram
Rotate it so thatThe amplitude isComing out of thepage
F
A This is really narrow because it is a slice in time
F
Time
Building a spectrogram
Dark bands= amplitudePeaks
Time
Freq
uenc
y
Building a spectrogram
Two main types of spectrograms
bull Narrow-band spectrogramsndash Akin to amplitude spectrums ldquolined uprdquondash Frequency resolution is really sharp
bull Wide-band spectrogramsndash Akin to spectrum envelopes ldquolined uprdquondash Frequency resolution not so sharp
Highlights harmonic structure
Highlights spectrum envelope
Wide vs Narrow Band Spectrograms
Learning Objectives
bull Define an acoustic filterbull Draw and label a frequency response curvebull Draw and differentiate different types of acoustic
filtersbull Define terms such as cutoff frequency center
frequency roll off rate gain and bandwidthbull Define and draw a basic filter system and relate that
to the source-filter theory of speech production
What is an ldquoAcousticrdquo Filter
bull holds back (attenuates) certain sounds and lets other sounds through - selective
Why might we be interested in filters
bull Human vocal tract acts like a frequency selective acoustic filter
bull Human auditory system behaves as a frequency selective filter
bull helps us understand how speech is produced and perceived
Kinds of frequency selective filters
Low-pass filtersndash Lets low frequencies ldquopass throughrdquo and attenuates high
frequencies
High-pass filtersndash Lets high frequencies ldquopass throughrdquo and attenuates low
frequencies
Band-pass filtersndash Lets a particular frequency range ldquopass throughrdquo and
attenuates other frequencies
Low Pass Filters
Frequencylow high
Gai
n
+
-
High Pass Filters
Frequencylow high
Gai
n
+
-
Band Pass Filter
Frequencylow high
Gai
n
+
-
Frequency Response Curve (FRC)
Frequencylow high
Gai
n
+
-
Center frequency
lower cutofffrequency
upper cutoff frequency
passband
3 dB
Operation of a filter on a signal
NOTE Amplitude spectrum describes a soundFrequency response curve describes a filter
Learning Objectivesbull Define resonance free and forced vibrationbull Describe how the pendulum and spring mass models can
help explain resonancebull Outline how mass and stiffness influences the resonant
frequency of a mass spring systembull Outline how acoustic resonators behave like acoustic filtersbull Calculate resonant frequencies of a uniform tube based on
its physical dimensionsbull Describe how the wavelength of the sound determines the
resonant frequency of tube
Free vibration
bull objects tend to vibrate at a characteristic or resonant frequency (RF)
Forced vibration
bull A vibrating system can force a nearby system into vibration
bull The efficiency with which this is accomplished is related to the similarity in the resonant frequency (RF) of the two systems
Forced vibration
bull If the RF of the two systems are the same the amplitude of forced vibration will be large
bull If the RF of the two systems are quite different the amplitude of forced vibration will be small or nonexistent
Resonance refers to
bull The tendency for an object to vibrate at a particular frequency or frequencies
bull The ability of a vibrating system to force another system into vibration
Back to the mass spring model
bull Vibratory frequency of the mass spring determined byndash Massndash Stiffness of the spring
httpphetcoloradoeduensimulationmass-spring-lab
Acoustic Resonance
bull Ideas from mechanical resonance also applies to acoustic systems
bull Acoustic chambers will transmit sound frequencies with more or less efficiency depending upon the physical characteristics
bull Therefore they act as filters passing through (and even amplifying) some frequencies and attentuating others
Acoustic Resonance
bull And since they act as filters they have most of the same features of a filter even though we might use different names
bull Center frequency is often termed the resonant frequency
bull Frequency response curve often termed the resonance curve
Helmholtz Resonator
Actions of a Helmholtz Resonator
Stephen M Tasko
Other Acoustic Resonators Tube Resonators
bull Uniform tubes Factors that influence resonancendash Lengthndash Cross-sectional area along its lengthndash Whether it is closed at either or both ends
Uniform tube closed at one end
Uniform tube closed at one end
Stephen M Tasko
Uniform tube closed at one end
First resonance or formant
F1 = c4lWhere
c=speed of sound (35000 cmsec)l = length of the tube
males ~ 175 cmfemales ~ 14 cm
Higher resonantformant frequencies are odd multiples of F1
For examplebull F1 = (c4l )1
bull F2 = (c4l )3
bull F3 = (c4l )5
Comparing Helmholtz and tube resonators
Resonator Features
Sharply tuned Broadly tuned
Resonator Features
An example of the resonance characteristics of the human vocal tract
Frequency
Gain
SPPA 4030 Speech Science
Topic 1 The Speech Chain
The Speech Chain (Denes amp Pinson 1993)
What information is embedded in the speech signal
Branches of science employed to understand speech communication
Physical Quantities Review An Independent Learning Activity
Assignment 1
Topic 2 The Source-Filter Theory of Speech Production An Intr
Producing Speech
Source-Filter Theory of Speech Production
Vocal tract is a tube that can vary its shape
Source Filter Theory
Same Source Different Filter
Different Source Same Filters
Different Source Same Filters (Human)
Different Source Same Filters (Human) (2)
Different Source Same Filters (Human) (3)
Different Source Same Filters (Human) (4)
Different Source Same Filters (Non-Human)
Different Source Same Filters (Non-Human) (2)
Different Source Same Filters (Non-Human) If it quacks like a
Source Filter Theory Applied Alaryngeal Speech
Source-Filter Theory Applied Esophageal Insufflation Test
Source-Filter Theory Applied Tracheoesophageal (TE) Speech
Source Filter Theory Applied The Talkbox
Source-Filter Theory Applied The Talkbox
Topic 3 A Brief Review of Physical Acoustics
Spring Mass Model
What is sound
Sound-conducting media
Model of air molecule vibration (Time 1)
Model of air molecule vibration (Time 2)
Model of air molecule vibration (Time 3)
Model of air molecule vibration (Time 4)
Model of air molecule vibration (Time 5)
Model of air molecule vibration
Wave action of molecular motion
Amplitude waveform
Amplitude waveform (2)
Where is pressure in this model
Pressure waveform
Measuring Sound
Measuring Sound Signal Amplitude
Measuring Sound Signal Amplitude (2)
What units do we use to measure signal amplitude
Brief Review The decibel scale
Absolute vs relative measurement
Typical reference values
Howeverhellip
Linear vs logarithmic
Linear vs logarithmic (2)
Logarithmic Scale
Logarithmic Scale (2)
Combining the idea of logarithmic and relativehellip
Intensity vs Pressure
Extending the formula to pressure
Measuring Sound Frequencyperiod
Measuring Sound Frequencyperiod (2)
Phase Uniform Circular Motion
Initiating a sound waves that differ only in phase
bull Complex gt one frequency componentbull Aperiodic Does not repeat itselfbull Frequency components are not systematically
relatedbull May be ndash Continuousndash Transient
Aperiodic sounds Graphic appearance
bull Time domainndash no repeating pattern of pressure change
bull Frequency domainndash the spectrum is dense ndash No ldquopicket fencerdquo
bull Auditory impression sounds lsquonoisyrsquo
Aperiodic sounds Graphic appearance
From Hillenbrand
>
Analysis of complex wavesbull Waves can be summedbull Complex waves are the sum of simple wavesbull Fourier French Mathematician
ndash Any complex waveform may be formed by summing sinusoids of various frequency amplitude and phase
bull Fourier Analysisndash Provides a unique (only one) solution for a given sound signalndash Is reflected in the amplitude and phase spectrum of the signalndash Reveals the building blocks of complex waves which are sinusoids
Learning Objectives
bull Draw and differentiate the waveform and the waveform envelope
bull Draw and differentiate the amplitude spectrum the phase spectrum and the spectrum envelope
bull Differential between short-term spectra and long-term average spectra
The ldquoenveloperdquo of a sound wave
bull Waveform envelopendash imaginary smooth line that follows the peak of the
amplitude of a sound pressure waveformbull Spectrum envelopendash Imaginary smooth line drawn on top of the
amplitude spectrum
Waveform envelope
From Hillenbrand
Waveform envelope
Time
>
Spectrum envelope
Frequency
Ampl
itude
Thought Question
Can an aperiodic and complex periodic sound have identical
spectrum envelopes
Amplitude Spectrum Window Size
bull ldquoshort-termrdquo vs ldquolong-term averagerdquo amplitude spectrum
ldquoInstantaneousrdquo Amplitude Spectra
(Long Term) Average Amplitude Spectrum
Learning Objectivesbull Describe how the amplitude spectrum and the spectrogram are
relatedbull Identify the axis units of the spectrogrambull Provide some advantages of the spectrogram over the
amplitude spectrumbull Distinguish between a wide band and narrow band spectrogram
and outline the different information each providesbull Distinguish between a harmonic and a formant on a
spectrogrambull Be able to draw stylized (highly simplified) spectrograms based
on spectra and spectrum envelopes
The Spectrogram
Rotate90 degrees
F
AF
A
Building a spectrogram
Rotate it so thatThe amplitude isComing out of thepage
F
A This is really narrow because it is a slice in time
F
Time
Building a spectrogram
Dark bands= amplitudePeaks
Time
Freq
uenc
y
Building a spectrogram
Two main types of spectrograms
bull Narrow-band spectrogramsndash Akin to amplitude spectrums ldquolined uprdquondash Frequency resolution is really sharp
bull Wide-band spectrogramsndash Akin to spectrum envelopes ldquolined uprdquondash Frequency resolution not so sharp
Highlights harmonic structure
Highlights spectrum envelope
Wide vs Narrow Band Spectrograms
Learning Objectives
bull Define an acoustic filterbull Draw and label a frequency response curvebull Draw and differentiate different types of acoustic
filtersbull Define terms such as cutoff frequency center
frequency roll off rate gain and bandwidthbull Define and draw a basic filter system and relate that
to the source-filter theory of speech production
What is an ldquoAcousticrdquo Filter
bull holds back (attenuates) certain sounds and lets other sounds through - selective
Why might we be interested in filters
bull Human vocal tract acts like a frequency selective acoustic filter
bull Human auditory system behaves as a frequency selective filter
bull helps us understand how speech is produced and perceived
Kinds of frequency selective filters
Low-pass filtersndash Lets low frequencies ldquopass throughrdquo and attenuates high
frequencies
High-pass filtersndash Lets high frequencies ldquopass throughrdquo and attenuates low
frequencies
Band-pass filtersndash Lets a particular frequency range ldquopass throughrdquo and
attenuates other frequencies
Low Pass Filters
Frequencylow high
Gai
n
+
-
High Pass Filters
Frequencylow high
Gai
n
+
-
Band Pass Filter
Frequencylow high
Gai
n
+
-
Frequency Response Curve (FRC)
Frequencylow high
Gai
n
+
-
Center frequency
lower cutofffrequency
upper cutoff frequency
passband
3 dB
Operation of a filter on a signal
NOTE Amplitude spectrum describes a soundFrequency response curve describes a filter
Learning Objectivesbull Define resonance free and forced vibrationbull Describe how the pendulum and spring mass models can
help explain resonancebull Outline how mass and stiffness influences the resonant
frequency of a mass spring systembull Outline how acoustic resonators behave like acoustic filtersbull Calculate resonant frequencies of a uniform tube based on
its physical dimensionsbull Describe how the wavelength of the sound determines the
resonant frequency of tube
Free vibration
bull objects tend to vibrate at a characteristic or resonant frequency (RF)
Forced vibration
bull A vibrating system can force a nearby system into vibration
bull The efficiency with which this is accomplished is related to the similarity in the resonant frequency (RF) of the two systems
Forced vibration
bull If the RF of the two systems are the same the amplitude of forced vibration will be large
bull If the RF of the two systems are quite different the amplitude of forced vibration will be small or nonexistent
Resonance refers to
bull The tendency for an object to vibrate at a particular frequency or frequencies
bull The ability of a vibrating system to force another system into vibration
Back to the mass spring model
bull Vibratory frequency of the mass spring determined byndash Massndash Stiffness of the spring
httpphetcoloradoeduensimulationmass-spring-lab
Acoustic Resonance
bull Ideas from mechanical resonance also applies to acoustic systems
bull Acoustic chambers will transmit sound frequencies with more or less efficiency depending upon the physical characteristics
bull Therefore they act as filters passing through (and even amplifying) some frequencies and attentuating others
Acoustic Resonance
bull And since they act as filters they have most of the same features of a filter even though we might use different names
bull Center frequency is often termed the resonant frequency
bull Frequency response curve often termed the resonance curve
Helmholtz Resonator
Actions of a Helmholtz Resonator
Stephen M Tasko
Other Acoustic Resonators Tube Resonators
bull Uniform tubes Factors that influence resonancendash Lengthndash Cross-sectional area along its lengthndash Whether it is closed at either or both ends
Uniform tube closed at one end
Uniform tube closed at one end
Stephen M Tasko
Uniform tube closed at one end
First resonance or formant
F1 = c4lWhere
c=speed of sound (35000 cmsec)l = length of the tube
males ~ 175 cmfemales ~ 14 cm
Higher resonantformant frequencies are odd multiples of F1
For examplebull F1 = (c4l )1
bull F2 = (c4l )3
bull F3 = (c4l )5
Comparing Helmholtz and tube resonators
Resonator Features
Sharply tuned Broadly tuned
Resonator Features
An example of the resonance characteristics of the human vocal tract
Frequency
Gain
SPPA 4030 Speech Science
Topic 1 The Speech Chain
The Speech Chain (Denes amp Pinson 1993)
What information is embedded in the speech signal
Branches of science employed to understand speech communication
Physical Quantities Review An Independent Learning Activity
Assignment 1
Topic 2 The Source-Filter Theory of Speech Production An Intr
Producing Speech
Source-Filter Theory of Speech Production
Vocal tract is a tube that can vary its shape
Source Filter Theory
Same Source Different Filter
Different Source Same Filters
Different Source Same Filters (Human)
Different Source Same Filters (Human) (2)
Different Source Same Filters (Human) (3)
Different Source Same Filters (Human) (4)
Different Source Same Filters (Non-Human)
Different Source Same Filters (Non-Human) (2)
Different Source Same Filters (Non-Human) If it quacks like a
Source Filter Theory Applied Alaryngeal Speech
Source-Filter Theory Applied Esophageal Insufflation Test
Source-Filter Theory Applied Tracheoesophageal (TE) Speech
Source Filter Theory Applied The Talkbox
Source-Filter Theory Applied The Talkbox
Topic 3 A Brief Review of Physical Acoustics
Spring Mass Model
What is sound
Sound-conducting media
Model of air molecule vibration (Time 1)
Model of air molecule vibration (Time 2)
Model of air molecule vibration (Time 3)
Model of air molecule vibration (Time 4)
Model of air molecule vibration (Time 5)
Model of air molecule vibration
Wave action of molecular motion
Amplitude waveform
Amplitude waveform (2)
Where is pressure in this model
Pressure waveform
Measuring Sound
Measuring Sound Signal Amplitude
Measuring Sound Signal Amplitude (2)
What units do we use to measure signal amplitude
Brief Review The decibel scale
Absolute vs relative measurement
Typical reference values
Howeverhellip
Linear vs logarithmic
Linear vs logarithmic (2)
Logarithmic Scale
Logarithmic Scale (2)
Combining the idea of logarithmic and relativehellip
Intensity vs Pressure
Extending the formula to pressure
Measuring Sound Frequencyperiod
Measuring Sound Frequencyperiod (2)
Phase Uniform Circular Motion
Initiating a sound waves that differ only in phase
bull Complex gt one frequency componentbull Aperiodic Does not repeat itselfbull Frequency components are not systematically
relatedbull May be ndash Continuousndash Transient
Aperiodic sounds Graphic appearance
bull Time domainndash no repeating pattern of pressure change
bull Frequency domainndash the spectrum is dense ndash No ldquopicket fencerdquo
bull Auditory impression sounds lsquonoisyrsquo
Aperiodic sounds Graphic appearance
From Hillenbrand
>
Analysis of complex wavesbull Waves can be summedbull Complex waves are the sum of simple wavesbull Fourier French Mathematician
ndash Any complex waveform may be formed by summing sinusoids of various frequency amplitude and phase
bull Fourier Analysisndash Provides a unique (only one) solution for a given sound signalndash Is reflected in the amplitude and phase spectrum of the signalndash Reveals the building blocks of complex waves which are sinusoids
Learning Objectives
bull Draw and differentiate the waveform and the waveform envelope
bull Draw and differentiate the amplitude spectrum the phase spectrum and the spectrum envelope
bull Differential between short-term spectra and long-term average spectra
The ldquoenveloperdquo of a sound wave
bull Waveform envelopendash imaginary smooth line that follows the peak of the
amplitude of a sound pressure waveformbull Spectrum envelopendash Imaginary smooth line drawn on top of the
amplitude spectrum
Waveform envelope
From Hillenbrand
Waveform envelope
Time
>
Spectrum envelope
Frequency
Ampl
itude
Thought Question
Can an aperiodic and complex periodic sound have identical
spectrum envelopes
Amplitude Spectrum Window Size
bull ldquoshort-termrdquo vs ldquolong-term averagerdquo amplitude spectrum
ldquoInstantaneousrdquo Amplitude Spectra
(Long Term) Average Amplitude Spectrum
Learning Objectivesbull Describe how the amplitude spectrum and the spectrogram are
relatedbull Identify the axis units of the spectrogrambull Provide some advantages of the spectrogram over the
amplitude spectrumbull Distinguish between a wide band and narrow band spectrogram
and outline the different information each providesbull Distinguish between a harmonic and a formant on a
spectrogrambull Be able to draw stylized (highly simplified) spectrograms based
on spectra and spectrum envelopes
The Spectrogram
Rotate90 degrees
F
AF
A
Building a spectrogram
Rotate it so thatThe amplitude isComing out of thepage
F
A This is really narrow because it is a slice in time
F
Time
Building a spectrogram
Dark bands= amplitudePeaks
Time
Freq
uenc
y
Building a spectrogram
Two main types of spectrograms
bull Narrow-band spectrogramsndash Akin to amplitude spectrums ldquolined uprdquondash Frequency resolution is really sharp
bull Wide-band spectrogramsndash Akin to spectrum envelopes ldquolined uprdquondash Frequency resolution not so sharp
Highlights harmonic structure
Highlights spectrum envelope
Wide vs Narrow Band Spectrograms
Learning Objectives
bull Define an acoustic filterbull Draw and label a frequency response curvebull Draw and differentiate different types of acoustic
filtersbull Define terms such as cutoff frequency center
frequency roll off rate gain and bandwidthbull Define and draw a basic filter system and relate that
to the source-filter theory of speech production
What is an ldquoAcousticrdquo Filter
bull holds back (attenuates) certain sounds and lets other sounds through - selective
Why might we be interested in filters
bull Human vocal tract acts like a frequency selective acoustic filter
bull Human auditory system behaves as a frequency selective filter
bull helps us understand how speech is produced and perceived
Kinds of frequency selective filters
Low-pass filtersndash Lets low frequencies ldquopass throughrdquo and attenuates high
frequencies
High-pass filtersndash Lets high frequencies ldquopass throughrdquo and attenuates low
frequencies
Band-pass filtersndash Lets a particular frequency range ldquopass throughrdquo and
attenuates other frequencies
Low Pass Filters
Frequencylow high
Gai
n
+
-
High Pass Filters
Frequencylow high
Gai
n
+
-
Band Pass Filter
Frequencylow high
Gai
n
+
-
Frequency Response Curve (FRC)
Frequencylow high
Gai
n
+
-
Center frequency
lower cutofffrequency
upper cutoff frequency
passband
3 dB
Operation of a filter on a signal
NOTE Amplitude spectrum describes a soundFrequency response curve describes a filter
Learning Objectivesbull Define resonance free and forced vibrationbull Describe how the pendulum and spring mass models can
help explain resonancebull Outline how mass and stiffness influences the resonant
frequency of a mass spring systembull Outline how acoustic resonators behave like acoustic filtersbull Calculate resonant frequencies of a uniform tube based on
its physical dimensionsbull Describe how the wavelength of the sound determines the
resonant frequency of tube
Free vibration
bull objects tend to vibrate at a characteristic or resonant frequency (RF)
Forced vibration
bull A vibrating system can force a nearby system into vibration
bull The efficiency with which this is accomplished is related to the similarity in the resonant frequency (RF) of the two systems
Forced vibration
bull If the RF of the two systems are the same the amplitude of forced vibration will be large
bull If the RF of the two systems are quite different the amplitude of forced vibration will be small or nonexistent
Resonance refers to
bull The tendency for an object to vibrate at a particular frequency or frequencies
bull The ability of a vibrating system to force another system into vibration
Back to the mass spring model
bull Vibratory frequency of the mass spring determined byndash Massndash Stiffness of the spring
httpphetcoloradoeduensimulationmass-spring-lab
Acoustic Resonance
bull Ideas from mechanical resonance also applies to acoustic systems
bull Acoustic chambers will transmit sound frequencies with more or less efficiency depending upon the physical characteristics
bull Therefore they act as filters passing through (and even amplifying) some frequencies and attentuating others
Acoustic Resonance
bull And since they act as filters they have most of the same features of a filter even though we might use different names
bull Center frequency is often termed the resonant frequency
bull Frequency response curve often termed the resonance curve
Helmholtz Resonator
Actions of a Helmholtz Resonator
Stephen M Tasko
Other Acoustic Resonators Tube Resonators
bull Uniform tubes Factors that influence resonancendash Lengthndash Cross-sectional area along its lengthndash Whether it is closed at either or both ends
Uniform tube closed at one end
Uniform tube closed at one end
Stephen M Tasko
Uniform tube closed at one end
First resonance or formant
F1 = c4lWhere
c=speed of sound (35000 cmsec)l = length of the tube
males ~ 175 cmfemales ~ 14 cm
Higher resonantformant frequencies are odd multiples of F1
For examplebull F1 = (c4l )1
bull F2 = (c4l )3
bull F3 = (c4l )5
Comparing Helmholtz and tube resonators
Resonator Features
Sharply tuned Broadly tuned
Resonator Features
An example of the resonance characteristics of the human vocal tract
Frequency
Gain
SPPA 4030 Speech Science
Topic 1 The Speech Chain
The Speech Chain (Denes amp Pinson 1993)
What information is embedded in the speech signal
Branches of science employed to understand speech communication
Physical Quantities Review An Independent Learning Activity
Assignment 1
Topic 2 The Source-Filter Theory of Speech Production An Intr
Producing Speech
Source-Filter Theory of Speech Production
Vocal tract is a tube that can vary its shape
Source Filter Theory
Same Source Different Filter
Different Source Same Filters
Different Source Same Filters (Human)
Different Source Same Filters (Human) (2)
Different Source Same Filters (Human) (3)
Different Source Same Filters (Human) (4)
Different Source Same Filters (Non-Human)
Different Source Same Filters (Non-Human) (2)
Different Source Same Filters (Non-Human) If it quacks like a
Source Filter Theory Applied Alaryngeal Speech
Source-Filter Theory Applied Esophageal Insufflation Test
Source-Filter Theory Applied Tracheoesophageal (TE) Speech
Source Filter Theory Applied The Talkbox
Source-Filter Theory Applied The Talkbox
Topic 3 A Brief Review of Physical Acoustics
Spring Mass Model
What is sound
Sound-conducting media
Model of air molecule vibration (Time 1)
Model of air molecule vibration (Time 2)
Model of air molecule vibration (Time 3)
Model of air molecule vibration (Time 4)
Model of air molecule vibration (Time 5)
Model of air molecule vibration
Wave action of molecular motion
Amplitude waveform
Amplitude waveform (2)
Where is pressure in this model
Pressure waveform
Measuring Sound
Measuring Sound Signal Amplitude
Measuring Sound Signal Amplitude (2)
What units do we use to measure signal amplitude
Brief Review The decibel scale
Absolute vs relative measurement
Typical reference values
Howeverhellip
Linear vs logarithmic
Linear vs logarithmic (2)
Logarithmic Scale
Logarithmic Scale (2)
Combining the idea of logarithmic and relativehellip
Intensity vs Pressure
Extending the formula to pressure
Measuring Sound Frequencyperiod
Measuring Sound Frequencyperiod (2)
Phase Uniform Circular Motion
Initiating a sound waves that differ only in phase
bull Complex gt one frequency componentbull Aperiodic Does not repeat itselfbull Frequency components are not systematically
relatedbull May be ndash Continuousndash Transient
Aperiodic sounds Graphic appearance
bull Time domainndash no repeating pattern of pressure change
bull Frequency domainndash the spectrum is dense ndash No ldquopicket fencerdquo
bull Auditory impression sounds lsquonoisyrsquo
Aperiodic sounds Graphic appearance
From Hillenbrand
>
Analysis of complex wavesbull Waves can be summedbull Complex waves are the sum of simple wavesbull Fourier French Mathematician
ndash Any complex waveform may be formed by summing sinusoids of various frequency amplitude and phase
bull Fourier Analysisndash Provides a unique (only one) solution for a given sound signalndash Is reflected in the amplitude and phase spectrum of the signalndash Reveals the building blocks of complex waves which are sinusoids
Learning Objectives
bull Draw and differentiate the waveform and the waveform envelope
bull Draw and differentiate the amplitude spectrum the phase spectrum and the spectrum envelope
bull Differential between short-term spectra and long-term average spectra
The ldquoenveloperdquo of a sound wave
bull Waveform envelopendash imaginary smooth line that follows the peak of the
amplitude of a sound pressure waveformbull Spectrum envelopendash Imaginary smooth line drawn on top of the
amplitude spectrum
Waveform envelope
From Hillenbrand
Waveform envelope
Time
>
Spectrum envelope
Frequency
Ampl
itude
Thought Question
Can an aperiodic and complex periodic sound have identical
spectrum envelopes
Amplitude Spectrum Window Size
bull ldquoshort-termrdquo vs ldquolong-term averagerdquo amplitude spectrum
ldquoInstantaneousrdquo Amplitude Spectra
(Long Term) Average Amplitude Spectrum
Learning Objectivesbull Describe how the amplitude spectrum and the spectrogram are
relatedbull Identify the axis units of the spectrogrambull Provide some advantages of the spectrogram over the
amplitude spectrumbull Distinguish between a wide band and narrow band spectrogram
and outline the different information each providesbull Distinguish between a harmonic and a formant on a
spectrogrambull Be able to draw stylized (highly simplified) spectrograms based
on spectra and spectrum envelopes
The Spectrogram
Rotate90 degrees
F
AF
A
Building a spectrogram
Rotate it so thatThe amplitude isComing out of thepage
F
A This is really narrow because it is a slice in time
F
Time
Building a spectrogram
Dark bands= amplitudePeaks
Time
Freq
uenc
y
Building a spectrogram
Two main types of spectrograms
bull Narrow-band spectrogramsndash Akin to amplitude spectrums ldquolined uprdquondash Frequency resolution is really sharp
bull Wide-band spectrogramsndash Akin to spectrum envelopes ldquolined uprdquondash Frequency resolution not so sharp
Highlights harmonic structure
Highlights spectrum envelope
Wide vs Narrow Band Spectrograms
Learning Objectives
bull Define an acoustic filterbull Draw and label a frequency response curvebull Draw and differentiate different types of acoustic
filtersbull Define terms such as cutoff frequency center
frequency roll off rate gain and bandwidthbull Define and draw a basic filter system and relate that
to the source-filter theory of speech production
What is an ldquoAcousticrdquo Filter
bull holds back (attenuates) certain sounds and lets other sounds through - selective
Why might we be interested in filters
bull Human vocal tract acts like a frequency selective acoustic filter
bull Human auditory system behaves as a frequency selective filter
bull helps us understand how speech is produced and perceived
Kinds of frequency selective filters
Low-pass filtersndash Lets low frequencies ldquopass throughrdquo and attenuates high
frequencies
High-pass filtersndash Lets high frequencies ldquopass throughrdquo and attenuates low
frequencies
Band-pass filtersndash Lets a particular frequency range ldquopass throughrdquo and
attenuates other frequencies
Low Pass Filters
Frequencylow high
Gai
n
+
-
High Pass Filters
Frequencylow high
Gai
n
+
-
Band Pass Filter
Frequencylow high
Gai
n
+
-
Frequency Response Curve (FRC)
Frequencylow high
Gai
n
+
-
Center frequency
lower cutofffrequency
upper cutoff frequency
passband
3 dB
Operation of a filter on a signal
NOTE Amplitude spectrum describes a soundFrequency response curve describes a filter
Learning Objectivesbull Define resonance free and forced vibrationbull Describe how the pendulum and spring mass models can
help explain resonancebull Outline how mass and stiffness influences the resonant
frequency of a mass spring systembull Outline how acoustic resonators behave like acoustic filtersbull Calculate resonant frequencies of a uniform tube based on
its physical dimensionsbull Describe how the wavelength of the sound determines the
resonant frequency of tube
Free vibration
bull objects tend to vibrate at a characteristic or resonant frequency (RF)
Forced vibration
bull A vibrating system can force a nearby system into vibration
bull The efficiency with which this is accomplished is related to the similarity in the resonant frequency (RF) of the two systems
Forced vibration
bull If the RF of the two systems are the same the amplitude of forced vibration will be large
bull If the RF of the two systems are quite different the amplitude of forced vibration will be small or nonexistent
Resonance refers to
bull The tendency for an object to vibrate at a particular frequency or frequencies
bull The ability of a vibrating system to force another system into vibration
Back to the mass spring model
bull Vibratory frequency of the mass spring determined byndash Massndash Stiffness of the spring
httpphetcoloradoeduensimulationmass-spring-lab
Acoustic Resonance
bull Ideas from mechanical resonance also applies to acoustic systems
bull Acoustic chambers will transmit sound frequencies with more or less efficiency depending upon the physical characteristics
bull Therefore they act as filters passing through (and even amplifying) some frequencies and attentuating others
Acoustic Resonance
bull And since they act as filters they have most of the same features of a filter even though we might use different names
bull Center frequency is often termed the resonant frequency
bull Frequency response curve often termed the resonance curve
Helmholtz Resonator
Actions of a Helmholtz Resonator
Stephen M Tasko
Other Acoustic Resonators Tube Resonators
bull Uniform tubes Factors that influence resonancendash Lengthndash Cross-sectional area along its lengthndash Whether it is closed at either or both ends
Uniform tube closed at one end
Uniform tube closed at one end
Stephen M Tasko
Uniform tube closed at one end
First resonance or formant
F1 = c4lWhere
c=speed of sound (35000 cmsec)l = length of the tube
males ~ 175 cmfemales ~ 14 cm
Higher resonantformant frequencies are odd multiples of F1
For examplebull F1 = (c4l )1
bull F2 = (c4l )3
bull F3 = (c4l )5
Comparing Helmholtz and tube resonators
Resonator Features
Sharply tuned Broadly tuned
Resonator Features
An example of the resonance characteristics of the human vocal tract
Frequency
Gain
SPPA 4030 Speech Science
Topic 1 The Speech Chain
The Speech Chain (Denes amp Pinson 1993)
What information is embedded in the speech signal
Branches of science employed to understand speech communication
Physical Quantities Review An Independent Learning Activity
Assignment 1
Topic 2 The Source-Filter Theory of Speech Production An Intr
Producing Speech
Source-Filter Theory of Speech Production
Vocal tract is a tube that can vary its shape
Source Filter Theory
Same Source Different Filter
Different Source Same Filters
Different Source Same Filters (Human)
Different Source Same Filters (Human) (2)
Different Source Same Filters (Human) (3)
Different Source Same Filters (Human) (4)
Different Source Same Filters (Non-Human)
Different Source Same Filters (Non-Human) (2)
Different Source Same Filters (Non-Human) If it quacks like a
Source Filter Theory Applied Alaryngeal Speech
Source-Filter Theory Applied Esophageal Insufflation Test
Source-Filter Theory Applied Tracheoesophageal (TE) Speech
Source Filter Theory Applied The Talkbox
Source-Filter Theory Applied The Talkbox
Topic 3 A Brief Review of Physical Acoustics
Spring Mass Model
What is sound
Sound-conducting media
Model of air molecule vibration (Time 1)
Model of air molecule vibration (Time 2)
Model of air molecule vibration (Time 3)
Model of air molecule vibration (Time 4)
Model of air molecule vibration (Time 5)
Model of air molecule vibration
Wave action of molecular motion
Amplitude waveform
Amplitude waveform (2)
Where is pressure in this model
Pressure waveform
Measuring Sound
Measuring Sound Signal Amplitude
Measuring Sound Signal Amplitude (2)
What units do we use to measure signal amplitude
Brief Review The decibel scale
Absolute vs relative measurement
Typical reference values
Howeverhellip
Linear vs logarithmic
Linear vs logarithmic (2)
Logarithmic Scale
Logarithmic Scale (2)
Combining the idea of logarithmic and relativehellip
Intensity vs Pressure
Extending the formula to pressure
Measuring Sound Frequencyperiod
Measuring Sound Frequencyperiod (2)
Phase Uniform Circular Motion
Initiating a sound waves that differ only in phase
bull Complex gt one frequency componentbull Aperiodic Does not repeat itselfbull Frequency components are not systematically
relatedbull May be ndash Continuousndash Transient
Aperiodic sounds Graphic appearance
bull Time domainndash no repeating pattern of pressure change
bull Frequency domainndash the spectrum is dense ndash No ldquopicket fencerdquo
bull Auditory impression sounds lsquonoisyrsquo
Aperiodic sounds Graphic appearance
From Hillenbrand
>
Analysis of complex wavesbull Waves can be summedbull Complex waves are the sum of simple wavesbull Fourier French Mathematician
ndash Any complex waveform may be formed by summing sinusoids of various frequency amplitude and phase
bull Fourier Analysisndash Provides a unique (only one) solution for a given sound signalndash Is reflected in the amplitude and phase spectrum of the signalndash Reveals the building blocks of complex waves which are sinusoids
Learning Objectives
bull Draw and differentiate the waveform and the waveform envelope
bull Draw and differentiate the amplitude spectrum the phase spectrum and the spectrum envelope
bull Differential between short-term spectra and long-term average spectra
The ldquoenveloperdquo of a sound wave
bull Waveform envelopendash imaginary smooth line that follows the peak of the
amplitude of a sound pressure waveformbull Spectrum envelopendash Imaginary smooth line drawn on top of the
amplitude spectrum
Waveform envelope
From Hillenbrand
Waveform envelope
Time
>
Spectrum envelope
Frequency
Ampl
itude
Thought Question
Can an aperiodic and complex periodic sound have identical
spectrum envelopes
Amplitude Spectrum Window Size
bull ldquoshort-termrdquo vs ldquolong-term averagerdquo amplitude spectrum
ldquoInstantaneousrdquo Amplitude Spectra
(Long Term) Average Amplitude Spectrum
Learning Objectivesbull Describe how the amplitude spectrum and the spectrogram are
relatedbull Identify the axis units of the spectrogrambull Provide some advantages of the spectrogram over the
amplitude spectrumbull Distinguish between a wide band and narrow band spectrogram
and outline the different information each providesbull Distinguish between a harmonic and a formant on a
spectrogrambull Be able to draw stylized (highly simplified) spectrograms based
on spectra and spectrum envelopes
The Spectrogram
Rotate90 degrees
F
AF
A
Building a spectrogram
Rotate it so thatThe amplitude isComing out of thepage
F
A This is really narrow because it is a slice in time
F
Time
Building a spectrogram
Dark bands= amplitudePeaks
Time
Freq
uenc
y
Building a spectrogram
Two main types of spectrograms
bull Narrow-band spectrogramsndash Akin to amplitude spectrums ldquolined uprdquondash Frequency resolution is really sharp
bull Wide-band spectrogramsndash Akin to spectrum envelopes ldquolined uprdquondash Frequency resolution not so sharp
Highlights harmonic structure
Highlights spectrum envelope
Wide vs Narrow Band Spectrograms
Learning Objectives
bull Define an acoustic filterbull Draw and label a frequency response curvebull Draw and differentiate different types of acoustic
filtersbull Define terms such as cutoff frequency center
frequency roll off rate gain and bandwidthbull Define and draw a basic filter system and relate that
to the source-filter theory of speech production
What is an ldquoAcousticrdquo Filter
bull holds back (attenuates) certain sounds and lets other sounds through - selective
Why might we be interested in filters
bull Human vocal tract acts like a frequency selective acoustic filter
bull Human auditory system behaves as a frequency selective filter
bull helps us understand how speech is produced and perceived
Kinds of frequency selective filters
Low-pass filtersndash Lets low frequencies ldquopass throughrdquo and attenuates high
frequencies
High-pass filtersndash Lets high frequencies ldquopass throughrdquo and attenuates low
frequencies
Band-pass filtersndash Lets a particular frequency range ldquopass throughrdquo and
attenuates other frequencies
Low Pass Filters
Frequencylow high
Gai
n
+
-
High Pass Filters
Frequencylow high
Gai
n
+
-
Band Pass Filter
Frequencylow high
Gai
n
+
-
Frequency Response Curve (FRC)
Frequencylow high
Gai
n
+
-
Center frequency
lower cutofffrequency
upper cutoff frequency
passband
3 dB
Operation of a filter on a signal
NOTE Amplitude spectrum describes a soundFrequency response curve describes a filter
Learning Objectivesbull Define resonance free and forced vibrationbull Describe how the pendulum and spring mass models can
help explain resonancebull Outline how mass and stiffness influences the resonant
frequency of a mass spring systembull Outline how acoustic resonators behave like acoustic filtersbull Calculate resonant frequencies of a uniform tube based on
its physical dimensionsbull Describe how the wavelength of the sound determines the
resonant frequency of tube
Free vibration
bull objects tend to vibrate at a characteristic or resonant frequency (RF)
Forced vibration
bull A vibrating system can force a nearby system into vibration
bull The efficiency with which this is accomplished is related to the similarity in the resonant frequency (RF) of the two systems
Forced vibration
bull If the RF of the two systems are the same the amplitude of forced vibration will be large
bull If the RF of the two systems are quite different the amplitude of forced vibration will be small or nonexistent
Resonance refers to
bull The tendency for an object to vibrate at a particular frequency or frequencies
bull The ability of a vibrating system to force another system into vibration
Back to the mass spring model
bull Vibratory frequency of the mass spring determined byndash Massndash Stiffness of the spring
httpphetcoloradoeduensimulationmass-spring-lab
Acoustic Resonance
bull Ideas from mechanical resonance also applies to acoustic systems
bull Acoustic chambers will transmit sound frequencies with more or less efficiency depending upon the physical characteristics
bull Therefore they act as filters passing through (and even amplifying) some frequencies and attentuating others
Acoustic Resonance
bull And since they act as filters they have most of the same features of a filter even though we might use different names
bull Center frequency is often termed the resonant frequency
bull Frequency response curve often termed the resonance curve
Helmholtz Resonator
Actions of a Helmholtz Resonator
Stephen M Tasko
Other Acoustic Resonators Tube Resonators
bull Uniform tubes Factors that influence resonancendash Lengthndash Cross-sectional area along its lengthndash Whether it is closed at either or both ends
Uniform tube closed at one end
Uniform tube closed at one end
Stephen M Tasko
Uniform tube closed at one end
First resonance or formant
F1 = c4lWhere
c=speed of sound (35000 cmsec)l = length of the tube
males ~ 175 cmfemales ~ 14 cm
Higher resonantformant frequencies are odd multiples of F1
For examplebull F1 = (c4l )1
bull F2 = (c4l )3
bull F3 = (c4l )5
Comparing Helmholtz and tube resonators
Resonator Features
Sharply tuned Broadly tuned
Resonator Features
An example of the resonance characteristics of the human vocal tract
Frequency
Gain
SPPA 4030 Speech Science
Topic 1 The Speech Chain
The Speech Chain (Denes amp Pinson 1993)
What information is embedded in the speech signal
Branches of science employed to understand speech communication
Physical Quantities Review An Independent Learning Activity
Assignment 1
Topic 2 The Source-Filter Theory of Speech Production An Intr
Producing Speech
Source-Filter Theory of Speech Production
Vocal tract is a tube that can vary its shape
Source Filter Theory
Same Source Different Filter
Different Source Same Filters
Different Source Same Filters (Human)
Different Source Same Filters (Human) (2)
Different Source Same Filters (Human) (3)
Different Source Same Filters (Human) (4)
Different Source Same Filters (Non-Human)
Different Source Same Filters (Non-Human) (2)
Different Source Same Filters (Non-Human) If it quacks like a
Source Filter Theory Applied Alaryngeal Speech
Source-Filter Theory Applied Esophageal Insufflation Test
Source-Filter Theory Applied Tracheoesophageal (TE) Speech
Source Filter Theory Applied The Talkbox
Source-Filter Theory Applied The Talkbox
Topic 3 A Brief Review of Physical Acoustics
Spring Mass Model
What is sound
Sound-conducting media
Model of air molecule vibration (Time 1)
Model of air molecule vibration (Time 2)
Model of air molecule vibration (Time 3)
Model of air molecule vibration (Time 4)
Model of air molecule vibration (Time 5)
Model of air molecule vibration
Wave action of molecular motion
Amplitude waveform
Amplitude waveform (2)
Where is pressure in this model
Pressure waveform
Measuring Sound
Measuring Sound Signal Amplitude
Measuring Sound Signal Amplitude (2)
What units do we use to measure signal amplitude
Brief Review The decibel scale
Absolute vs relative measurement
Typical reference values
Howeverhellip
Linear vs logarithmic
Linear vs logarithmic (2)
Logarithmic Scale
Logarithmic Scale (2)
Combining the idea of logarithmic and relativehellip
Intensity vs Pressure
Extending the formula to pressure
Measuring Sound Frequencyperiod
Measuring Sound Frequencyperiod (2)
Phase Uniform Circular Motion
Initiating a sound waves that differ only in phase
bull Complex gt one frequency componentbull Aperiodic Does not repeat itselfbull Frequency components are not systematically
relatedbull May be ndash Continuousndash Transient
Aperiodic sounds Graphic appearance
bull Time domainndash no repeating pattern of pressure change
bull Frequency domainndash the spectrum is dense ndash No ldquopicket fencerdquo
bull Auditory impression sounds lsquonoisyrsquo
Aperiodic sounds Graphic appearance
From Hillenbrand
>
Analysis of complex wavesbull Waves can be summedbull Complex waves are the sum of simple wavesbull Fourier French Mathematician
ndash Any complex waveform may be formed by summing sinusoids of various frequency amplitude and phase
bull Fourier Analysisndash Provides a unique (only one) solution for a given sound signalndash Is reflected in the amplitude and phase spectrum of the signalndash Reveals the building blocks of complex waves which are sinusoids
Learning Objectives
bull Draw and differentiate the waveform and the waveform envelope
bull Draw and differentiate the amplitude spectrum the phase spectrum and the spectrum envelope
bull Differential between short-term spectra and long-term average spectra
The ldquoenveloperdquo of a sound wave
bull Waveform envelopendash imaginary smooth line that follows the peak of the
amplitude of a sound pressure waveformbull Spectrum envelopendash Imaginary smooth line drawn on top of the
amplitude spectrum
Waveform envelope
From Hillenbrand
Waveform envelope
Time
>
Spectrum envelope
Frequency
Ampl
itude
Thought Question
Can an aperiodic and complex periodic sound have identical
spectrum envelopes
Amplitude Spectrum Window Size
bull ldquoshort-termrdquo vs ldquolong-term averagerdquo amplitude spectrum
ldquoInstantaneousrdquo Amplitude Spectra
(Long Term) Average Amplitude Spectrum
Learning Objectivesbull Describe how the amplitude spectrum and the spectrogram are
relatedbull Identify the axis units of the spectrogrambull Provide some advantages of the spectrogram over the
amplitude spectrumbull Distinguish between a wide band and narrow band spectrogram
and outline the different information each providesbull Distinguish between a harmonic and a formant on a
spectrogrambull Be able to draw stylized (highly simplified) spectrograms based
on spectra and spectrum envelopes
The Spectrogram
Rotate90 degrees
F
AF
A
Building a spectrogram
Rotate it so thatThe amplitude isComing out of thepage
F
A This is really narrow because it is a slice in time
F
Time
Building a spectrogram
Dark bands= amplitudePeaks
Time
Freq
uenc
y
Building a spectrogram
Two main types of spectrograms
bull Narrow-band spectrogramsndash Akin to amplitude spectrums ldquolined uprdquondash Frequency resolution is really sharp
bull Wide-band spectrogramsndash Akin to spectrum envelopes ldquolined uprdquondash Frequency resolution not so sharp
Highlights harmonic structure
Highlights spectrum envelope
Wide vs Narrow Band Spectrograms
Learning Objectives
bull Define an acoustic filterbull Draw and label a frequency response curvebull Draw and differentiate different types of acoustic
filtersbull Define terms such as cutoff frequency center
frequency roll off rate gain and bandwidthbull Define and draw a basic filter system and relate that
to the source-filter theory of speech production
What is an ldquoAcousticrdquo Filter
bull holds back (attenuates) certain sounds and lets other sounds through - selective
Why might we be interested in filters
bull Human vocal tract acts like a frequency selective acoustic filter
bull Human auditory system behaves as a frequency selective filter
bull helps us understand how speech is produced and perceived
Kinds of frequency selective filters
Low-pass filtersndash Lets low frequencies ldquopass throughrdquo and attenuates high
frequencies
High-pass filtersndash Lets high frequencies ldquopass throughrdquo and attenuates low
frequencies
Band-pass filtersndash Lets a particular frequency range ldquopass throughrdquo and
attenuates other frequencies
Low Pass Filters
Frequencylow high
Gai
n
+
-
High Pass Filters
Frequencylow high
Gai
n
+
-
Band Pass Filter
Frequencylow high
Gai
n
+
-
Frequency Response Curve (FRC)
Frequencylow high
Gai
n
+
-
Center frequency
lower cutofffrequency
upper cutoff frequency
passband
3 dB
Operation of a filter on a signal
NOTE Amplitude spectrum describes a soundFrequency response curve describes a filter
Learning Objectivesbull Define resonance free and forced vibrationbull Describe how the pendulum and spring mass models can
help explain resonancebull Outline how mass and stiffness influences the resonant
frequency of a mass spring systembull Outline how acoustic resonators behave like acoustic filtersbull Calculate resonant frequencies of a uniform tube based on
its physical dimensionsbull Describe how the wavelength of the sound determines the
resonant frequency of tube
Free vibration
bull objects tend to vibrate at a characteristic or resonant frequency (RF)
Forced vibration
bull A vibrating system can force a nearby system into vibration
bull The efficiency with which this is accomplished is related to the similarity in the resonant frequency (RF) of the two systems
Forced vibration
bull If the RF of the two systems are the same the amplitude of forced vibration will be large
bull If the RF of the two systems are quite different the amplitude of forced vibration will be small or nonexistent
Resonance refers to
bull The tendency for an object to vibrate at a particular frequency or frequencies
bull The ability of a vibrating system to force another system into vibration
Back to the mass spring model
bull Vibratory frequency of the mass spring determined byndash Massndash Stiffness of the spring
httpphetcoloradoeduensimulationmass-spring-lab
Acoustic Resonance
bull Ideas from mechanical resonance also applies to acoustic systems
bull Acoustic chambers will transmit sound frequencies with more or less efficiency depending upon the physical characteristics
bull Therefore they act as filters passing through (and even amplifying) some frequencies and attentuating others
Acoustic Resonance
bull And since they act as filters they have most of the same features of a filter even though we might use different names
bull Center frequency is often termed the resonant frequency
bull Frequency response curve often termed the resonance curve
Helmholtz Resonator
Actions of a Helmholtz Resonator
Stephen M Tasko
Other Acoustic Resonators Tube Resonators
bull Uniform tubes Factors that influence resonancendash Lengthndash Cross-sectional area along its lengthndash Whether it is closed at either or both ends
Uniform tube closed at one end
Uniform tube closed at one end
Stephen M Tasko
Uniform tube closed at one end
First resonance or formant
F1 = c4lWhere
c=speed of sound (35000 cmsec)l = length of the tube
males ~ 175 cmfemales ~ 14 cm
Higher resonantformant frequencies are odd multiples of F1
For examplebull F1 = (c4l )1
bull F2 = (c4l )3
bull F3 = (c4l )5
Comparing Helmholtz and tube resonators
Resonator Features
Sharply tuned Broadly tuned
Resonator Features
An example of the resonance characteristics of the human vocal tract
Frequency
Gain
SPPA 4030 Speech Science
Topic 1 The Speech Chain
The Speech Chain (Denes amp Pinson 1993)
What information is embedded in the speech signal
Branches of science employed to understand speech communication
Physical Quantities Review An Independent Learning Activity
Assignment 1
Topic 2 The Source-Filter Theory of Speech Production An Intr
Producing Speech
Source-Filter Theory of Speech Production
Vocal tract is a tube that can vary its shape
Source Filter Theory
Same Source Different Filter
Different Source Same Filters
Different Source Same Filters (Human)
Different Source Same Filters (Human) (2)
Different Source Same Filters (Human) (3)
Different Source Same Filters (Human) (4)
Different Source Same Filters (Non-Human)
Different Source Same Filters (Non-Human) (2)
Different Source Same Filters (Non-Human) If it quacks like a
Source Filter Theory Applied Alaryngeal Speech
Source-Filter Theory Applied Esophageal Insufflation Test
Source-Filter Theory Applied Tracheoesophageal (TE) Speech
Source Filter Theory Applied The Talkbox
Source-Filter Theory Applied The Talkbox
Topic 3 A Brief Review of Physical Acoustics
Spring Mass Model
What is sound
Sound-conducting media
Model of air molecule vibration (Time 1)
Model of air molecule vibration (Time 2)
Model of air molecule vibration (Time 3)
Model of air molecule vibration (Time 4)
Model of air molecule vibration (Time 5)
Model of air molecule vibration
Wave action of molecular motion
Amplitude waveform
Amplitude waveform (2)
Where is pressure in this model
Pressure waveform
Measuring Sound
Measuring Sound Signal Amplitude
Measuring Sound Signal Amplitude (2)
What units do we use to measure signal amplitude
Brief Review The decibel scale
Absolute vs relative measurement
Typical reference values
Howeverhellip
Linear vs logarithmic
Linear vs logarithmic (2)
Logarithmic Scale
Logarithmic Scale (2)
Combining the idea of logarithmic and relativehellip
Intensity vs Pressure
Extending the formula to pressure
Measuring Sound Frequencyperiod
Measuring Sound Frequencyperiod (2)
Phase Uniform Circular Motion
Initiating a sound waves that differ only in phase
bull Complex gt one frequency componentbull Aperiodic Does not repeat itselfbull Frequency components are not systematically
relatedbull May be ndash Continuousndash Transient
Aperiodic sounds Graphic appearance
bull Time domainndash no repeating pattern of pressure change
bull Frequency domainndash the spectrum is dense ndash No ldquopicket fencerdquo
bull Auditory impression sounds lsquonoisyrsquo
Aperiodic sounds Graphic appearance
From Hillenbrand
>
Analysis of complex wavesbull Waves can be summedbull Complex waves are the sum of simple wavesbull Fourier French Mathematician
ndash Any complex waveform may be formed by summing sinusoids of various frequency amplitude and phase
bull Fourier Analysisndash Provides a unique (only one) solution for a given sound signalndash Is reflected in the amplitude and phase spectrum of the signalndash Reveals the building blocks of complex waves which are sinusoids
Learning Objectives
bull Draw and differentiate the waveform and the waveform envelope
bull Draw and differentiate the amplitude spectrum the phase spectrum and the spectrum envelope
bull Differential between short-term spectra and long-term average spectra
The ldquoenveloperdquo of a sound wave
bull Waveform envelopendash imaginary smooth line that follows the peak of the
amplitude of a sound pressure waveformbull Spectrum envelopendash Imaginary smooth line drawn on top of the
amplitude spectrum
Waveform envelope
From Hillenbrand
Waveform envelope
Time
>
Spectrum envelope
Frequency
Ampl
itude
Thought Question
Can an aperiodic and complex periodic sound have identical
spectrum envelopes
Amplitude Spectrum Window Size
bull ldquoshort-termrdquo vs ldquolong-term averagerdquo amplitude spectrum
ldquoInstantaneousrdquo Amplitude Spectra
(Long Term) Average Amplitude Spectrum
Learning Objectivesbull Describe how the amplitude spectrum and the spectrogram are
relatedbull Identify the axis units of the spectrogrambull Provide some advantages of the spectrogram over the
amplitude spectrumbull Distinguish between a wide band and narrow band spectrogram
and outline the different information each providesbull Distinguish between a harmonic and a formant on a
spectrogrambull Be able to draw stylized (highly simplified) spectrograms based
on spectra and spectrum envelopes
The Spectrogram
Rotate90 degrees
F
AF
A
Building a spectrogram
Rotate it so thatThe amplitude isComing out of thepage
F
A This is really narrow because it is a slice in time
F
Time
Building a spectrogram
Dark bands= amplitudePeaks
Time
Freq
uenc
y
Building a spectrogram
Two main types of spectrograms
bull Narrow-band spectrogramsndash Akin to amplitude spectrums ldquolined uprdquondash Frequency resolution is really sharp
bull Wide-band spectrogramsndash Akin to spectrum envelopes ldquolined uprdquondash Frequency resolution not so sharp
Highlights harmonic structure
Highlights spectrum envelope
Wide vs Narrow Band Spectrograms
Learning Objectives
bull Define an acoustic filterbull Draw and label a frequency response curvebull Draw and differentiate different types of acoustic
filtersbull Define terms such as cutoff frequency center
frequency roll off rate gain and bandwidthbull Define and draw a basic filter system and relate that
to the source-filter theory of speech production
What is an ldquoAcousticrdquo Filter
bull holds back (attenuates) certain sounds and lets other sounds through - selective
Why might we be interested in filters
bull Human vocal tract acts like a frequency selective acoustic filter
bull Human auditory system behaves as a frequency selective filter
bull helps us understand how speech is produced and perceived
Kinds of frequency selective filters
Low-pass filtersndash Lets low frequencies ldquopass throughrdquo and attenuates high
frequencies
High-pass filtersndash Lets high frequencies ldquopass throughrdquo and attenuates low
frequencies
Band-pass filtersndash Lets a particular frequency range ldquopass throughrdquo and
attenuates other frequencies
Low Pass Filters
Frequencylow high
Gai
n
+
-
High Pass Filters
Frequencylow high
Gai
n
+
-
Band Pass Filter
Frequencylow high
Gai
n
+
-
Frequency Response Curve (FRC)
Frequencylow high
Gai
n
+
-
Center frequency
lower cutofffrequency
upper cutoff frequency
passband
3 dB
Operation of a filter on a signal
NOTE Amplitude spectrum describes a soundFrequency response curve describes a filter
Learning Objectivesbull Define resonance free and forced vibrationbull Describe how the pendulum and spring mass models can
help explain resonancebull Outline how mass and stiffness influences the resonant
frequency of a mass spring systembull Outline how acoustic resonators behave like acoustic filtersbull Calculate resonant frequencies of a uniform tube based on
its physical dimensionsbull Describe how the wavelength of the sound determines the
resonant frequency of tube
Free vibration
bull objects tend to vibrate at a characteristic or resonant frequency (RF)
Forced vibration
bull A vibrating system can force a nearby system into vibration
bull The efficiency with which this is accomplished is related to the similarity in the resonant frequency (RF) of the two systems
Forced vibration
bull If the RF of the two systems are the same the amplitude of forced vibration will be large
bull If the RF of the two systems are quite different the amplitude of forced vibration will be small or nonexistent
Resonance refers to
bull The tendency for an object to vibrate at a particular frequency or frequencies
bull The ability of a vibrating system to force another system into vibration
Back to the mass spring model
bull Vibratory frequency of the mass spring determined byndash Massndash Stiffness of the spring
httpphetcoloradoeduensimulationmass-spring-lab
Acoustic Resonance
bull Ideas from mechanical resonance also applies to acoustic systems
bull Acoustic chambers will transmit sound frequencies with more or less efficiency depending upon the physical characteristics
bull Therefore they act as filters passing through (and even amplifying) some frequencies and attentuating others
Acoustic Resonance
bull And since they act as filters they have most of the same features of a filter even though we might use different names
bull Center frequency is often termed the resonant frequency
bull Frequency response curve often termed the resonance curve
Helmholtz Resonator
Actions of a Helmholtz Resonator
Stephen M Tasko
Other Acoustic Resonators Tube Resonators
bull Uniform tubes Factors that influence resonancendash Lengthndash Cross-sectional area along its lengthndash Whether it is closed at either or both ends
Uniform tube closed at one end
Uniform tube closed at one end
Stephen M Tasko
Uniform tube closed at one end
First resonance or formant
F1 = c4lWhere
c=speed of sound (35000 cmsec)l = length of the tube
males ~ 175 cmfemales ~ 14 cm
Higher resonantformant frequencies are odd multiples of F1
For examplebull F1 = (c4l )1
bull F2 = (c4l )3
bull F3 = (c4l )5
Comparing Helmholtz and tube resonators
Resonator Features
Sharply tuned Broadly tuned
Resonator Features
An example of the resonance characteristics of the human vocal tract
Frequency
Gain
SPPA 4030 Speech Science
Topic 1 The Speech Chain
The Speech Chain (Denes amp Pinson 1993)
What information is embedded in the speech signal
Branches of science employed to understand speech communication
Physical Quantities Review An Independent Learning Activity
Assignment 1
Topic 2 The Source-Filter Theory of Speech Production An Intr
Producing Speech
Source-Filter Theory of Speech Production
Vocal tract is a tube that can vary its shape
Source Filter Theory
Same Source Different Filter
Different Source Same Filters
Different Source Same Filters (Human)
Different Source Same Filters (Human) (2)
Different Source Same Filters (Human) (3)
Different Source Same Filters (Human) (4)
Different Source Same Filters (Non-Human)
Different Source Same Filters (Non-Human) (2)
Different Source Same Filters (Non-Human) If it quacks like a
Source Filter Theory Applied Alaryngeal Speech
Source-Filter Theory Applied Esophageal Insufflation Test
Source-Filter Theory Applied Tracheoesophageal (TE) Speech
Source Filter Theory Applied The Talkbox
Source-Filter Theory Applied The Talkbox
Topic 3 A Brief Review of Physical Acoustics
Spring Mass Model
What is sound
Sound-conducting media
Model of air molecule vibration (Time 1)
Model of air molecule vibration (Time 2)
Model of air molecule vibration (Time 3)
Model of air molecule vibration (Time 4)
Model of air molecule vibration (Time 5)
Model of air molecule vibration
Wave action of molecular motion
Amplitude waveform
Amplitude waveform (2)
Where is pressure in this model
Pressure waveform
Measuring Sound
Measuring Sound Signal Amplitude
Measuring Sound Signal Amplitude (2)
What units do we use to measure signal amplitude
Brief Review The decibel scale
Absolute vs relative measurement
Typical reference values
Howeverhellip
Linear vs logarithmic
Linear vs logarithmic (2)
Logarithmic Scale
Logarithmic Scale (2)
Combining the idea of logarithmic and relativehellip
Intensity vs Pressure
Extending the formula to pressure
Measuring Sound Frequencyperiod
Measuring Sound Frequencyperiod (2)
Phase Uniform Circular Motion
Initiating a sound waves that differ only in phase
bull Complex gt one frequency componentbull Aperiodic Does not repeat itselfbull Frequency components are not systematically
relatedbull May be ndash Continuousndash Transient
Aperiodic sounds Graphic appearance
bull Time domainndash no repeating pattern of pressure change
bull Frequency domainndash the spectrum is dense ndash No ldquopicket fencerdquo
bull Auditory impression sounds lsquonoisyrsquo
Aperiodic sounds Graphic appearance
From Hillenbrand
>
Analysis of complex wavesbull Waves can be summedbull Complex waves are the sum of simple wavesbull Fourier French Mathematician
ndash Any complex waveform may be formed by summing sinusoids of various frequency amplitude and phase
bull Fourier Analysisndash Provides a unique (only one) solution for a given sound signalndash Is reflected in the amplitude and phase spectrum of the signalndash Reveals the building blocks of complex waves which are sinusoids
Learning Objectives
bull Draw and differentiate the waveform and the waveform envelope
bull Draw and differentiate the amplitude spectrum the phase spectrum and the spectrum envelope
bull Differential between short-term spectra and long-term average spectra
The ldquoenveloperdquo of a sound wave
bull Waveform envelopendash imaginary smooth line that follows the peak of the
amplitude of a sound pressure waveformbull Spectrum envelopendash Imaginary smooth line drawn on top of the
amplitude spectrum
Waveform envelope
From Hillenbrand
Waveform envelope
Time
>
Spectrum envelope
Frequency
Ampl
itude
Thought Question
Can an aperiodic and complex periodic sound have identical
spectrum envelopes
Amplitude Spectrum Window Size
bull ldquoshort-termrdquo vs ldquolong-term averagerdquo amplitude spectrum
ldquoInstantaneousrdquo Amplitude Spectra
(Long Term) Average Amplitude Spectrum
Learning Objectivesbull Describe how the amplitude spectrum and the spectrogram are
relatedbull Identify the axis units of the spectrogrambull Provide some advantages of the spectrogram over the
amplitude spectrumbull Distinguish between a wide band and narrow band spectrogram
and outline the different information each providesbull Distinguish between a harmonic and a formant on a
spectrogrambull Be able to draw stylized (highly simplified) spectrograms based
on spectra and spectrum envelopes
The Spectrogram
Rotate90 degrees
F
AF
A
Building a spectrogram
Rotate it so thatThe amplitude isComing out of thepage
F
A This is really narrow because it is a slice in time
F
Time
Building a spectrogram
Dark bands= amplitudePeaks
Time
Freq
uenc
y
Building a spectrogram
Two main types of spectrograms
bull Narrow-band spectrogramsndash Akin to amplitude spectrums ldquolined uprdquondash Frequency resolution is really sharp
bull Wide-band spectrogramsndash Akin to spectrum envelopes ldquolined uprdquondash Frequency resolution not so sharp
Highlights harmonic structure
Highlights spectrum envelope
Wide vs Narrow Band Spectrograms
Learning Objectives
bull Define an acoustic filterbull Draw and label a frequency response curvebull Draw and differentiate different types of acoustic
filtersbull Define terms such as cutoff frequency center
frequency roll off rate gain and bandwidthbull Define and draw a basic filter system and relate that
to the source-filter theory of speech production
What is an ldquoAcousticrdquo Filter
bull holds back (attenuates) certain sounds and lets other sounds through - selective
Why might we be interested in filters
bull Human vocal tract acts like a frequency selective acoustic filter
bull Human auditory system behaves as a frequency selective filter
bull helps us understand how speech is produced and perceived
Kinds of frequency selective filters
Low-pass filtersndash Lets low frequencies ldquopass throughrdquo and attenuates high
frequencies
High-pass filtersndash Lets high frequencies ldquopass throughrdquo and attenuates low
frequencies
Band-pass filtersndash Lets a particular frequency range ldquopass throughrdquo and
attenuates other frequencies
Low Pass Filters
Frequencylow high
Gai
n
+
-
High Pass Filters
Frequencylow high
Gai
n
+
-
Band Pass Filter
Frequencylow high
Gai
n
+
-
Frequency Response Curve (FRC)
Frequencylow high
Gai
n
+
-
Center frequency
lower cutofffrequency
upper cutoff frequency
passband
3 dB
Operation of a filter on a signal
NOTE Amplitude spectrum describes a soundFrequency response curve describes a filter
Learning Objectivesbull Define resonance free and forced vibrationbull Describe how the pendulum and spring mass models can
help explain resonancebull Outline how mass and stiffness influences the resonant
frequency of a mass spring systembull Outline how acoustic resonators behave like acoustic filtersbull Calculate resonant frequencies of a uniform tube based on
its physical dimensionsbull Describe how the wavelength of the sound determines the
resonant frequency of tube
Free vibration
bull objects tend to vibrate at a characteristic or resonant frequency (RF)
Forced vibration
bull A vibrating system can force a nearby system into vibration
bull The efficiency with which this is accomplished is related to the similarity in the resonant frequency (RF) of the two systems
Forced vibration
bull If the RF of the two systems are the same the amplitude of forced vibration will be large
bull If the RF of the two systems are quite different the amplitude of forced vibration will be small or nonexistent
Resonance refers to
bull The tendency for an object to vibrate at a particular frequency or frequencies
bull The ability of a vibrating system to force another system into vibration
Back to the mass spring model
bull Vibratory frequency of the mass spring determined byndash Massndash Stiffness of the spring
httpphetcoloradoeduensimulationmass-spring-lab
Acoustic Resonance
bull Ideas from mechanical resonance also applies to acoustic systems
bull Acoustic chambers will transmit sound frequencies with more or less efficiency depending upon the physical characteristics
bull Therefore they act as filters passing through (and even amplifying) some frequencies and attentuating others
Acoustic Resonance
bull And since they act as filters they have most of the same features of a filter even though we might use different names
bull Center frequency is often termed the resonant frequency
bull Frequency response curve often termed the resonance curve
Helmholtz Resonator
Actions of a Helmholtz Resonator
Stephen M Tasko
Other Acoustic Resonators Tube Resonators
bull Uniform tubes Factors that influence resonancendash Lengthndash Cross-sectional area along its lengthndash Whether it is closed at either or both ends
Uniform tube closed at one end
Uniform tube closed at one end
Stephen M Tasko
Uniform tube closed at one end
First resonance or formant
F1 = c4lWhere
c=speed of sound (35000 cmsec)l = length of the tube
males ~ 175 cmfemales ~ 14 cm
Higher resonantformant frequencies are odd multiples of F1
For examplebull F1 = (c4l )1
bull F2 = (c4l )3
bull F3 = (c4l )5
Comparing Helmholtz and tube resonators
Resonator Features
Sharply tuned Broadly tuned
Resonator Features
An example of the resonance characteristics of the human vocal tract
Frequency
Gain
SPPA 4030 Speech Science
Topic 1 The Speech Chain
The Speech Chain (Denes amp Pinson 1993)
What information is embedded in the speech signal
Branches of science employed to understand speech communication
Physical Quantities Review An Independent Learning Activity
Assignment 1
Topic 2 The Source-Filter Theory of Speech Production An Intr
Producing Speech
Source-Filter Theory of Speech Production
Vocal tract is a tube that can vary its shape
Source Filter Theory
Same Source Different Filter
Different Source Same Filters
Different Source Same Filters (Human)
Different Source Same Filters (Human) (2)
Different Source Same Filters (Human) (3)
Different Source Same Filters (Human) (4)
Different Source Same Filters (Non-Human)
Different Source Same Filters (Non-Human) (2)
Different Source Same Filters (Non-Human) If it quacks like a
Source Filter Theory Applied Alaryngeal Speech
Source-Filter Theory Applied Esophageal Insufflation Test
Source-Filter Theory Applied Tracheoesophageal (TE) Speech
Source Filter Theory Applied The Talkbox
Source-Filter Theory Applied The Talkbox
Topic 3 A Brief Review of Physical Acoustics
Spring Mass Model
What is sound
Sound-conducting media
Model of air molecule vibration (Time 1)
Model of air molecule vibration (Time 2)
Model of air molecule vibration (Time 3)
Model of air molecule vibration (Time 4)
Model of air molecule vibration (Time 5)
Model of air molecule vibration
Wave action of molecular motion
Amplitude waveform
Amplitude waveform (2)
Where is pressure in this model
Pressure waveform
Measuring Sound
Measuring Sound Signal Amplitude
Measuring Sound Signal Amplitude (2)
What units do we use to measure signal amplitude
Brief Review The decibel scale
Absolute vs relative measurement
Typical reference values
Howeverhellip
Linear vs logarithmic
Linear vs logarithmic (2)
Logarithmic Scale
Logarithmic Scale (2)
Combining the idea of logarithmic and relativehellip
Intensity vs Pressure
Extending the formula to pressure
Measuring Sound Frequencyperiod
Measuring Sound Frequencyperiod (2)
Phase Uniform Circular Motion
Initiating a sound waves that differ only in phase
bull Complex gt one frequency componentbull Aperiodic Does not repeat itselfbull Frequency components are not systematically
relatedbull May be ndash Continuousndash Transient
Aperiodic sounds Graphic appearance
bull Time domainndash no repeating pattern of pressure change
bull Frequency domainndash the spectrum is dense ndash No ldquopicket fencerdquo
bull Auditory impression sounds lsquonoisyrsquo
Aperiodic sounds Graphic appearance
From Hillenbrand
>
Analysis of complex wavesbull Waves can be summedbull Complex waves are the sum of simple wavesbull Fourier French Mathematician
ndash Any complex waveform may be formed by summing sinusoids of various frequency amplitude and phase
bull Fourier Analysisndash Provides a unique (only one) solution for a given sound signalndash Is reflected in the amplitude and phase spectrum of the signalndash Reveals the building blocks of complex waves which are sinusoids
Learning Objectives
bull Draw and differentiate the waveform and the waveform envelope
bull Draw and differentiate the amplitude spectrum the phase spectrum and the spectrum envelope
bull Differential between short-term spectra and long-term average spectra
The ldquoenveloperdquo of a sound wave
bull Waveform envelopendash imaginary smooth line that follows the peak of the
amplitude of a sound pressure waveformbull Spectrum envelopendash Imaginary smooth line drawn on top of the
amplitude spectrum
Waveform envelope
From Hillenbrand
Waveform envelope
Time
>
Spectrum envelope
Frequency
Ampl
itude
Thought Question
Can an aperiodic and complex periodic sound have identical
spectrum envelopes
Amplitude Spectrum Window Size
bull ldquoshort-termrdquo vs ldquolong-term averagerdquo amplitude spectrum
ldquoInstantaneousrdquo Amplitude Spectra
(Long Term) Average Amplitude Spectrum
Learning Objectivesbull Describe how the amplitude spectrum and the spectrogram are
relatedbull Identify the axis units of the spectrogrambull Provide some advantages of the spectrogram over the
amplitude spectrumbull Distinguish between a wide band and narrow band spectrogram
and outline the different information each providesbull Distinguish between a harmonic and a formant on a
spectrogrambull Be able to draw stylized (highly simplified) spectrograms based
on spectra and spectrum envelopes
The Spectrogram
Rotate90 degrees
F
AF
A
Building a spectrogram
Rotate it so thatThe amplitude isComing out of thepage
F
A This is really narrow because it is a slice in time
F
Time
Building a spectrogram
Dark bands= amplitudePeaks
Time
Freq
uenc
y
Building a spectrogram
Two main types of spectrograms
bull Narrow-band spectrogramsndash Akin to amplitude spectrums ldquolined uprdquondash Frequency resolution is really sharp
bull Wide-band spectrogramsndash Akin to spectrum envelopes ldquolined uprdquondash Frequency resolution not so sharp
Highlights harmonic structure
Highlights spectrum envelope
Wide vs Narrow Band Spectrograms
Learning Objectives
bull Define an acoustic filterbull Draw and label a frequency response curvebull Draw and differentiate different types of acoustic
filtersbull Define terms such as cutoff frequency center
frequency roll off rate gain and bandwidthbull Define and draw a basic filter system and relate that
to the source-filter theory of speech production
What is an ldquoAcousticrdquo Filter
bull holds back (attenuates) certain sounds and lets other sounds through - selective
Why might we be interested in filters
bull Human vocal tract acts like a frequency selective acoustic filter
bull Human auditory system behaves as a frequency selective filter
bull helps us understand how speech is produced and perceived
Kinds of frequency selective filters
Low-pass filtersndash Lets low frequencies ldquopass throughrdquo and attenuates high
frequencies
High-pass filtersndash Lets high frequencies ldquopass throughrdquo and attenuates low
frequencies
Band-pass filtersndash Lets a particular frequency range ldquopass throughrdquo and
attenuates other frequencies
Low Pass Filters
Frequencylow high
Gai
n
+
-
High Pass Filters
Frequencylow high
Gai
n
+
-
Band Pass Filter
Frequencylow high
Gai
n
+
-
Frequency Response Curve (FRC)
Frequencylow high
Gai
n
+
-
Center frequency
lower cutofffrequency
upper cutoff frequency
passband
3 dB
Operation of a filter on a signal
NOTE Amplitude spectrum describes a soundFrequency response curve describes a filter
Learning Objectivesbull Define resonance free and forced vibrationbull Describe how the pendulum and spring mass models can
help explain resonancebull Outline how mass and stiffness influences the resonant
frequency of a mass spring systembull Outline how acoustic resonators behave like acoustic filtersbull Calculate resonant frequencies of a uniform tube based on
its physical dimensionsbull Describe how the wavelength of the sound determines the
resonant frequency of tube
Free vibration
bull objects tend to vibrate at a characteristic or resonant frequency (RF)
Forced vibration
bull A vibrating system can force a nearby system into vibration
bull The efficiency with which this is accomplished is related to the similarity in the resonant frequency (RF) of the two systems
Forced vibration
bull If the RF of the two systems are the same the amplitude of forced vibration will be large
bull If the RF of the two systems are quite different the amplitude of forced vibration will be small or nonexistent
Resonance refers to
bull The tendency for an object to vibrate at a particular frequency or frequencies
bull The ability of a vibrating system to force another system into vibration
Back to the mass spring model
bull Vibratory frequency of the mass spring determined byndash Massndash Stiffness of the spring
httpphetcoloradoeduensimulationmass-spring-lab
Acoustic Resonance
bull Ideas from mechanical resonance also applies to acoustic systems
bull Acoustic chambers will transmit sound frequencies with more or less efficiency depending upon the physical characteristics
bull Therefore they act as filters passing through (and even amplifying) some frequencies and attentuating others
Acoustic Resonance
bull And since they act as filters they have most of the same features of a filter even though we might use different names
bull Center frequency is often termed the resonant frequency
bull Frequency response curve often termed the resonance curve
Helmholtz Resonator
Actions of a Helmholtz Resonator
Stephen M Tasko
Other Acoustic Resonators Tube Resonators
bull Uniform tubes Factors that influence resonancendash Lengthndash Cross-sectional area along its lengthndash Whether it is closed at either or both ends
Uniform tube closed at one end
Uniform tube closed at one end
Stephen M Tasko
Uniform tube closed at one end
First resonance or formant
F1 = c4lWhere
c=speed of sound (35000 cmsec)l = length of the tube
males ~ 175 cmfemales ~ 14 cm
Higher resonantformant frequencies are odd multiples of F1
For examplebull F1 = (c4l )1
bull F2 = (c4l )3
bull F3 = (c4l )5
Comparing Helmholtz and tube resonators
Resonator Features
Sharply tuned Broadly tuned
Resonator Features
An example of the resonance characteristics of the human vocal tract
Frequency
Gain
SPPA 4030 Speech Science
Topic 1 The Speech Chain
The Speech Chain (Denes amp Pinson 1993)
What information is embedded in the speech signal
Branches of science employed to understand speech communication
Physical Quantities Review An Independent Learning Activity
Assignment 1
Topic 2 The Source-Filter Theory of Speech Production An Intr
Producing Speech
Source-Filter Theory of Speech Production
Vocal tract is a tube that can vary its shape
Source Filter Theory
Same Source Different Filter
Different Source Same Filters
Different Source Same Filters (Human)
Different Source Same Filters (Human) (2)
Different Source Same Filters (Human) (3)
Different Source Same Filters (Human) (4)
Different Source Same Filters (Non-Human)
Different Source Same Filters (Non-Human) (2)
Different Source Same Filters (Non-Human) If it quacks like a
Source Filter Theory Applied Alaryngeal Speech
Source-Filter Theory Applied Esophageal Insufflation Test
Source-Filter Theory Applied Tracheoesophageal (TE) Speech
Source Filter Theory Applied The Talkbox
Source-Filter Theory Applied The Talkbox
Topic 3 A Brief Review of Physical Acoustics
Spring Mass Model
What is sound
Sound-conducting media
Model of air molecule vibration (Time 1)
Model of air molecule vibration (Time 2)
Model of air molecule vibration (Time 3)
Model of air molecule vibration (Time 4)
Model of air molecule vibration (Time 5)
Model of air molecule vibration
Wave action of molecular motion
Amplitude waveform
Amplitude waveform (2)
Where is pressure in this model
Pressure waveform
Measuring Sound
Measuring Sound Signal Amplitude
Measuring Sound Signal Amplitude (2)
What units do we use to measure signal amplitude
Brief Review The decibel scale
Absolute vs relative measurement
Typical reference values
Howeverhellip
Linear vs logarithmic
Linear vs logarithmic (2)
Logarithmic Scale
Logarithmic Scale (2)
Combining the idea of logarithmic and relativehellip
Intensity vs Pressure
Extending the formula to pressure
Measuring Sound Frequencyperiod
Measuring Sound Frequencyperiod (2)
Phase Uniform Circular Motion
Initiating a sound waves that differ only in phase
bull Complex gt one frequency componentbull Aperiodic Does not repeat itselfbull Frequency components are not systematically
relatedbull May be ndash Continuousndash Transient
Aperiodic sounds Graphic appearance
bull Time domainndash no repeating pattern of pressure change
bull Frequency domainndash the spectrum is dense ndash No ldquopicket fencerdquo
bull Auditory impression sounds lsquonoisyrsquo
Aperiodic sounds Graphic appearance
From Hillenbrand
>
Analysis of complex wavesbull Waves can be summedbull Complex waves are the sum of simple wavesbull Fourier French Mathematician
ndash Any complex waveform may be formed by summing sinusoids of various frequency amplitude and phase
bull Fourier Analysisndash Provides a unique (only one) solution for a given sound signalndash Is reflected in the amplitude and phase spectrum of the signalndash Reveals the building blocks of complex waves which are sinusoids
Learning Objectives
bull Draw and differentiate the waveform and the waveform envelope
bull Draw and differentiate the amplitude spectrum the phase spectrum and the spectrum envelope
bull Differential between short-term spectra and long-term average spectra
The ldquoenveloperdquo of a sound wave
bull Waveform envelopendash imaginary smooth line that follows the peak of the
amplitude of a sound pressure waveformbull Spectrum envelopendash Imaginary smooth line drawn on top of the
amplitude spectrum
Waveform envelope
From Hillenbrand
Waveform envelope
Time
>
Spectrum envelope
Frequency
Ampl
itude
Thought Question
Can an aperiodic and complex periodic sound have identical
spectrum envelopes
Amplitude Spectrum Window Size
bull ldquoshort-termrdquo vs ldquolong-term averagerdquo amplitude spectrum
ldquoInstantaneousrdquo Amplitude Spectra
(Long Term) Average Amplitude Spectrum
Learning Objectivesbull Describe how the amplitude spectrum and the spectrogram are
relatedbull Identify the axis units of the spectrogrambull Provide some advantages of the spectrogram over the
amplitude spectrumbull Distinguish between a wide band and narrow band spectrogram
and outline the different information each providesbull Distinguish between a harmonic and a formant on a
spectrogrambull Be able to draw stylized (highly simplified) spectrograms based
on spectra and spectrum envelopes
The Spectrogram
Rotate90 degrees
F
AF
A
Building a spectrogram
Rotate it so thatThe amplitude isComing out of thepage
F
A This is really narrow because it is a slice in time
F
Time
Building a spectrogram
Dark bands= amplitudePeaks
Time
Freq
uenc
y
Building a spectrogram
Two main types of spectrograms
bull Narrow-band spectrogramsndash Akin to amplitude spectrums ldquolined uprdquondash Frequency resolution is really sharp
bull Wide-band spectrogramsndash Akin to spectrum envelopes ldquolined uprdquondash Frequency resolution not so sharp
Highlights harmonic structure
Highlights spectrum envelope
Wide vs Narrow Band Spectrograms
Learning Objectives
bull Define an acoustic filterbull Draw and label a frequency response curvebull Draw and differentiate different types of acoustic
filtersbull Define terms such as cutoff frequency center
frequency roll off rate gain and bandwidthbull Define and draw a basic filter system and relate that
to the source-filter theory of speech production
What is an ldquoAcousticrdquo Filter
bull holds back (attenuates) certain sounds and lets other sounds through - selective
Why might we be interested in filters
bull Human vocal tract acts like a frequency selective acoustic filter
bull Human auditory system behaves as a frequency selective filter
bull helps us understand how speech is produced and perceived
Kinds of frequency selective filters
Low-pass filtersndash Lets low frequencies ldquopass throughrdquo and attenuates high
frequencies
High-pass filtersndash Lets high frequencies ldquopass throughrdquo and attenuates low
frequencies
Band-pass filtersndash Lets a particular frequency range ldquopass throughrdquo and
attenuates other frequencies
Low Pass Filters
Frequencylow high
Gai
n
+
-
High Pass Filters
Frequencylow high
Gai
n
+
-
Band Pass Filter
Frequencylow high
Gai
n
+
-
Frequency Response Curve (FRC)
Frequencylow high
Gai
n
+
-
Center frequency
lower cutofffrequency
upper cutoff frequency
passband
3 dB
Operation of a filter on a signal
NOTE Amplitude spectrum describes a soundFrequency response curve describes a filter
Learning Objectivesbull Define resonance free and forced vibrationbull Describe how the pendulum and spring mass models can
help explain resonancebull Outline how mass and stiffness influences the resonant
frequency of a mass spring systembull Outline how acoustic resonators behave like acoustic filtersbull Calculate resonant frequencies of a uniform tube based on
its physical dimensionsbull Describe how the wavelength of the sound determines the
resonant frequency of tube
Free vibration
bull objects tend to vibrate at a characteristic or resonant frequency (RF)
Forced vibration
bull A vibrating system can force a nearby system into vibration
bull The efficiency with which this is accomplished is related to the similarity in the resonant frequency (RF) of the two systems
Forced vibration
bull If the RF of the two systems are the same the amplitude of forced vibration will be large
bull If the RF of the two systems are quite different the amplitude of forced vibration will be small or nonexistent
Resonance refers to
bull The tendency for an object to vibrate at a particular frequency or frequencies
bull The ability of a vibrating system to force another system into vibration
Back to the mass spring model
bull Vibratory frequency of the mass spring determined byndash Massndash Stiffness of the spring
httpphetcoloradoeduensimulationmass-spring-lab
Acoustic Resonance
bull Ideas from mechanical resonance also applies to acoustic systems
bull Acoustic chambers will transmit sound frequencies with more or less efficiency depending upon the physical characteristics
bull Therefore they act as filters passing through (and even amplifying) some frequencies and attentuating others
Acoustic Resonance
bull And since they act as filters they have most of the same features of a filter even though we might use different names
bull Center frequency is often termed the resonant frequency
bull Frequency response curve often termed the resonance curve
Helmholtz Resonator
Actions of a Helmholtz Resonator
Stephen M Tasko
Other Acoustic Resonators Tube Resonators
bull Uniform tubes Factors that influence resonancendash Lengthndash Cross-sectional area along its lengthndash Whether it is closed at either or both ends
Uniform tube closed at one end
Uniform tube closed at one end
Stephen M Tasko
Uniform tube closed at one end
First resonance or formant
F1 = c4lWhere
c=speed of sound (35000 cmsec)l = length of the tube
males ~ 175 cmfemales ~ 14 cm
Higher resonantformant frequencies are odd multiples of F1
For examplebull F1 = (c4l )1
bull F2 = (c4l )3
bull F3 = (c4l )5
Comparing Helmholtz and tube resonators
Resonator Features
Sharply tuned Broadly tuned
Resonator Features
An example of the resonance characteristics of the human vocal tract
Frequency
Gain
SPPA 4030 Speech Science
Topic 1 The Speech Chain
The Speech Chain (Denes amp Pinson 1993)
What information is embedded in the speech signal
Branches of science employed to understand speech communication
Physical Quantities Review An Independent Learning Activity
Assignment 1
Topic 2 The Source-Filter Theory of Speech Production An Intr
Producing Speech
Source-Filter Theory of Speech Production
Vocal tract is a tube that can vary its shape
Source Filter Theory
Same Source Different Filter
Different Source Same Filters
Different Source Same Filters (Human)
Different Source Same Filters (Human) (2)
Different Source Same Filters (Human) (3)
Different Source Same Filters (Human) (4)
Different Source Same Filters (Non-Human)
Different Source Same Filters (Non-Human) (2)
Different Source Same Filters (Non-Human) If it quacks like a
Source Filter Theory Applied Alaryngeal Speech
Source-Filter Theory Applied Esophageal Insufflation Test
Source-Filter Theory Applied Tracheoesophageal (TE) Speech
Source Filter Theory Applied The Talkbox
Source-Filter Theory Applied The Talkbox
Topic 3 A Brief Review of Physical Acoustics
Spring Mass Model
What is sound
Sound-conducting media
Model of air molecule vibration (Time 1)
Model of air molecule vibration (Time 2)
Model of air molecule vibration (Time 3)
Model of air molecule vibration (Time 4)
Model of air molecule vibration (Time 5)
Model of air molecule vibration
Wave action of molecular motion
Amplitude waveform
Amplitude waveform (2)
Where is pressure in this model
Pressure waveform
Measuring Sound
Measuring Sound Signal Amplitude
Measuring Sound Signal Amplitude (2)
What units do we use to measure signal amplitude
Brief Review The decibel scale
Absolute vs relative measurement
Typical reference values
Howeverhellip
Linear vs logarithmic
Linear vs logarithmic (2)
Logarithmic Scale
Logarithmic Scale (2)
Combining the idea of logarithmic and relativehellip
Intensity vs Pressure
Extending the formula to pressure
Measuring Sound Frequencyperiod
Measuring Sound Frequencyperiod (2)
Phase Uniform Circular Motion
Initiating a sound waves that differ only in phase
bull Complex gt one frequency componentbull Aperiodic Does not repeat itselfbull Frequency components are not systematically
relatedbull May be ndash Continuousndash Transient
Aperiodic sounds Graphic appearance
bull Time domainndash no repeating pattern of pressure change
bull Frequency domainndash the spectrum is dense ndash No ldquopicket fencerdquo
bull Auditory impression sounds lsquonoisyrsquo
Aperiodic sounds Graphic appearance
From Hillenbrand
>
Analysis of complex wavesbull Waves can be summedbull Complex waves are the sum of simple wavesbull Fourier French Mathematician
ndash Any complex waveform may be formed by summing sinusoids of various frequency amplitude and phase
bull Fourier Analysisndash Provides a unique (only one) solution for a given sound signalndash Is reflected in the amplitude and phase spectrum of the signalndash Reveals the building blocks of complex waves which are sinusoids
Learning Objectives
bull Draw and differentiate the waveform and the waveform envelope
bull Draw and differentiate the amplitude spectrum the phase spectrum and the spectrum envelope
bull Differential between short-term spectra and long-term average spectra
The ldquoenveloperdquo of a sound wave
bull Waveform envelopendash imaginary smooth line that follows the peak of the
amplitude of a sound pressure waveformbull Spectrum envelopendash Imaginary smooth line drawn on top of the
amplitude spectrum
Waveform envelope
From Hillenbrand
Waveform envelope
Time
>
Spectrum envelope
Frequency
Ampl
itude
Thought Question
Can an aperiodic and complex periodic sound have identical
spectrum envelopes
Amplitude Spectrum Window Size
bull ldquoshort-termrdquo vs ldquolong-term averagerdquo amplitude spectrum
ldquoInstantaneousrdquo Amplitude Spectra
(Long Term) Average Amplitude Spectrum
Learning Objectivesbull Describe how the amplitude spectrum and the spectrogram are
relatedbull Identify the axis units of the spectrogrambull Provide some advantages of the spectrogram over the
amplitude spectrumbull Distinguish between a wide band and narrow band spectrogram
and outline the different information each providesbull Distinguish between a harmonic and a formant on a
spectrogrambull Be able to draw stylized (highly simplified) spectrograms based
on spectra and spectrum envelopes
The Spectrogram
Rotate90 degrees
F
AF
A
Building a spectrogram
Rotate it so thatThe amplitude isComing out of thepage
F
A This is really narrow because it is a slice in time
F
Time
Building a spectrogram
Dark bands= amplitudePeaks
Time
Freq
uenc
y
Building a spectrogram
Two main types of spectrograms
bull Narrow-band spectrogramsndash Akin to amplitude spectrums ldquolined uprdquondash Frequency resolution is really sharp
bull Wide-band spectrogramsndash Akin to spectrum envelopes ldquolined uprdquondash Frequency resolution not so sharp
Highlights harmonic structure
Highlights spectrum envelope
Wide vs Narrow Band Spectrograms
Learning Objectives
bull Define an acoustic filterbull Draw and label a frequency response curvebull Draw and differentiate different types of acoustic
filtersbull Define terms such as cutoff frequency center
frequency roll off rate gain and bandwidthbull Define and draw a basic filter system and relate that
to the source-filter theory of speech production
What is an ldquoAcousticrdquo Filter
bull holds back (attenuates) certain sounds and lets other sounds through - selective
Why might we be interested in filters
bull Human vocal tract acts like a frequency selective acoustic filter
bull Human auditory system behaves as a frequency selective filter
bull helps us understand how speech is produced and perceived
Kinds of frequency selective filters
Low-pass filtersndash Lets low frequencies ldquopass throughrdquo and attenuates high
frequencies
High-pass filtersndash Lets high frequencies ldquopass throughrdquo and attenuates low
frequencies
Band-pass filtersndash Lets a particular frequency range ldquopass throughrdquo and
attenuates other frequencies
Low Pass Filters
Frequencylow high
Gai
n
+
-
High Pass Filters
Frequencylow high
Gai
n
+
-
Band Pass Filter
Frequencylow high
Gai
n
+
-
Frequency Response Curve (FRC)
Frequencylow high
Gai
n
+
-
Center frequency
lower cutofffrequency
upper cutoff frequency
passband
3 dB
Operation of a filter on a signal
NOTE Amplitude spectrum describes a soundFrequency response curve describes a filter
Learning Objectivesbull Define resonance free and forced vibrationbull Describe how the pendulum and spring mass models can
help explain resonancebull Outline how mass and stiffness influences the resonant
frequency of a mass spring systembull Outline how acoustic resonators behave like acoustic filtersbull Calculate resonant frequencies of a uniform tube based on
its physical dimensionsbull Describe how the wavelength of the sound determines the
resonant frequency of tube
Free vibration
bull objects tend to vibrate at a characteristic or resonant frequency (RF)
Forced vibration
bull A vibrating system can force a nearby system into vibration
bull The efficiency with which this is accomplished is related to the similarity in the resonant frequency (RF) of the two systems
Forced vibration
bull If the RF of the two systems are the same the amplitude of forced vibration will be large
bull If the RF of the two systems are quite different the amplitude of forced vibration will be small or nonexistent
Resonance refers to
bull The tendency for an object to vibrate at a particular frequency or frequencies
bull The ability of a vibrating system to force another system into vibration
Back to the mass spring model
bull Vibratory frequency of the mass spring determined byndash Massndash Stiffness of the spring
httpphetcoloradoeduensimulationmass-spring-lab
Acoustic Resonance
bull Ideas from mechanical resonance also applies to acoustic systems
bull Acoustic chambers will transmit sound frequencies with more or less efficiency depending upon the physical characteristics
bull Therefore they act as filters passing through (and even amplifying) some frequencies and attentuating others
Acoustic Resonance
bull And since they act as filters they have most of the same features of a filter even though we might use different names
bull Center frequency is often termed the resonant frequency
bull Frequency response curve often termed the resonance curve
Helmholtz Resonator
Actions of a Helmholtz Resonator
Stephen M Tasko
Other Acoustic Resonators Tube Resonators
bull Uniform tubes Factors that influence resonancendash Lengthndash Cross-sectional area along its lengthndash Whether it is closed at either or both ends
Uniform tube closed at one end
Uniform tube closed at one end
Stephen M Tasko
Uniform tube closed at one end
First resonance or formant
F1 = c4lWhere
c=speed of sound (35000 cmsec)l = length of the tube
males ~ 175 cmfemales ~ 14 cm
Higher resonantformant frequencies are odd multiples of F1
For examplebull F1 = (c4l )1
bull F2 = (c4l )3
bull F3 = (c4l )5
Comparing Helmholtz and tube resonators
Resonator Features
Sharply tuned Broadly tuned
Resonator Features
An example of the resonance characteristics of the human vocal tract
Frequency
Gain
SPPA 4030 Speech Science
Topic 1 The Speech Chain
The Speech Chain (Denes amp Pinson 1993)
What information is embedded in the speech signal
Branches of science employed to understand speech communication
Physical Quantities Review An Independent Learning Activity
Assignment 1
Topic 2 The Source-Filter Theory of Speech Production An Intr
Producing Speech
Source-Filter Theory of Speech Production
Vocal tract is a tube that can vary its shape
Source Filter Theory
Same Source Different Filter
Different Source Same Filters
Different Source Same Filters (Human)
Different Source Same Filters (Human) (2)
Different Source Same Filters (Human) (3)
Different Source Same Filters (Human) (4)
Different Source Same Filters (Non-Human)
Different Source Same Filters (Non-Human) (2)
Different Source Same Filters (Non-Human) If it quacks like a
Source Filter Theory Applied Alaryngeal Speech
Source-Filter Theory Applied Esophageal Insufflation Test
Source-Filter Theory Applied Tracheoesophageal (TE) Speech
Source Filter Theory Applied The Talkbox
Source-Filter Theory Applied The Talkbox
Topic 3 A Brief Review of Physical Acoustics
Spring Mass Model
What is sound
Sound-conducting media
Model of air molecule vibration (Time 1)
Model of air molecule vibration (Time 2)
Model of air molecule vibration (Time 3)
Model of air molecule vibration (Time 4)
Model of air molecule vibration (Time 5)
Model of air molecule vibration
Wave action of molecular motion
Amplitude waveform
Amplitude waveform (2)
Where is pressure in this model
Pressure waveform
Measuring Sound
Measuring Sound Signal Amplitude
Measuring Sound Signal Amplitude (2)
What units do we use to measure signal amplitude
Brief Review The decibel scale
Absolute vs relative measurement
Typical reference values
Howeverhellip
Linear vs logarithmic
Linear vs logarithmic (2)
Logarithmic Scale
Logarithmic Scale (2)
Combining the idea of logarithmic and relativehellip
Intensity vs Pressure
Extending the formula to pressure
Measuring Sound Frequencyperiod
Measuring Sound Frequencyperiod (2)
Phase Uniform Circular Motion
Initiating a sound waves that differ only in phase
bull Complex gt one frequency componentbull Aperiodic Does not repeat itselfbull Frequency components are not systematically
relatedbull May be ndash Continuousndash Transient
Aperiodic sounds Graphic appearance
bull Time domainndash no repeating pattern of pressure change
bull Frequency domainndash the spectrum is dense ndash No ldquopicket fencerdquo
bull Auditory impression sounds lsquonoisyrsquo
Aperiodic sounds Graphic appearance
From Hillenbrand
>
Analysis of complex wavesbull Waves can be summedbull Complex waves are the sum of simple wavesbull Fourier French Mathematician
ndash Any complex waveform may be formed by summing sinusoids of various frequency amplitude and phase
bull Fourier Analysisndash Provides a unique (only one) solution for a given sound signalndash Is reflected in the amplitude and phase spectrum of the signalndash Reveals the building blocks of complex waves which are sinusoids
Learning Objectives
bull Draw and differentiate the waveform and the waveform envelope
bull Draw and differentiate the amplitude spectrum the phase spectrum and the spectrum envelope
bull Differential between short-term spectra and long-term average spectra
The ldquoenveloperdquo of a sound wave
bull Waveform envelopendash imaginary smooth line that follows the peak of the
amplitude of a sound pressure waveformbull Spectrum envelopendash Imaginary smooth line drawn on top of the
amplitude spectrum
Waveform envelope
From Hillenbrand
Waveform envelope
Time
>
Spectrum envelope
Frequency
Ampl
itude
Thought Question
Can an aperiodic and complex periodic sound have identical
spectrum envelopes
Amplitude Spectrum Window Size
bull ldquoshort-termrdquo vs ldquolong-term averagerdquo amplitude spectrum
ldquoInstantaneousrdquo Amplitude Spectra
(Long Term) Average Amplitude Spectrum
Learning Objectivesbull Describe how the amplitude spectrum and the spectrogram are
relatedbull Identify the axis units of the spectrogrambull Provide some advantages of the spectrogram over the
amplitude spectrumbull Distinguish between a wide band and narrow band spectrogram
and outline the different information each providesbull Distinguish between a harmonic and a formant on a
spectrogrambull Be able to draw stylized (highly simplified) spectrograms based
on spectra and spectrum envelopes
The Spectrogram
Rotate90 degrees
F
AF
A
Building a spectrogram
Rotate it so thatThe amplitude isComing out of thepage
F
A This is really narrow because it is a slice in time
F
Time
Building a spectrogram
Dark bands= amplitudePeaks
Time
Freq
uenc
y
Building a spectrogram
Two main types of spectrograms
bull Narrow-band spectrogramsndash Akin to amplitude spectrums ldquolined uprdquondash Frequency resolution is really sharp
bull Wide-band spectrogramsndash Akin to spectrum envelopes ldquolined uprdquondash Frequency resolution not so sharp
Highlights harmonic structure
Highlights spectrum envelope
Wide vs Narrow Band Spectrograms
Learning Objectives
bull Define an acoustic filterbull Draw and label a frequency response curvebull Draw and differentiate different types of acoustic
filtersbull Define terms such as cutoff frequency center
frequency roll off rate gain and bandwidthbull Define and draw a basic filter system and relate that
to the source-filter theory of speech production
What is an ldquoAcousticrdquo Filter
bull holds back (attenuates) certain sounds and lets other sounds through - selective
Why might we be interested in filters
bull Human vocal tract acts like a frequency selective acoustic filter
bull Human auditory system behaves as a frequency selective filter
bull helps us understand how speech is produced and perceived
Kinds of frequency selective filters
Low-pass filtersndash Lets low frequencies ldquopass throughrdquo and attenuates high
frequencies
High-pass filtersndash Lets high frequencies ldquopass throughrdquo and attenuates low
frequencies
Band-pass filtersndash Lets a particular frequency range ldquopass throughrdquo and
attenuates other frequencies
Low Pass Filters
Frequencylow high
Gai
n
+
-
High Pass Filters
Frequencylow high
Gai
n
+
-
Band Pass Filter
Frequencylow high
Gai
n
+
-
Frequency Response Curve (FRC)
Frequencylow high
Gai
n
+
-
Center frequency
lower cutofffrequency
upper cutoff frequency
passband
3 dB
Operation of a filter on a signal
NOTE Amplitude spectrum describes a soundFrequency response curve describes a filter
Learning Objectivesbull Define resonance free and forced vibrationbull Describe how the pendulum and spring mass models can
help explain resonancebull Outline how mass and stiffness influences the resonant
frequency of a mass spring systembull Outline how acoustic resonators behave like acoustic filtersbull Calculate resonant frequencies of a uniform tube based on
its physical dimensionsbull Describe how the wavelength of the sound determines the
resonant frequency of tube
Free vibration
bull objects tend to vibrate at a characteristic or resonant frequency (RF)
Forced vibration
bull A vibrating system can force a nearby system into vibration
bull The efficiency with which this is accomplished is related to the similarity in the resonant frequency (RF) of the two systems
Forced vibration
bull If the RF of the two systems are the same the amplitude of forced vibration will be large
bull If the RF of the two systems are quite different the amplitude of forced vibration will be small or nonexistent
Resonance refers to
bull The tendency for an object to vibrate at a particular frequency or frequencies
bull The ability of a vibrating system to force another system into vibration
Back to the mass spring model
bull Vibratory frequency of the mass spring determined byndash Massndash Stiffness of the spring
httpphetcoloradoeduensimulationmass-spring-lab
Acoustic Resonance
bull Ideas from mechanical resonance also applies to acoustic systems
bull Acoustic chambers will transmit sound frequencies with more or less efficiency depending upon the physical characteristics
bull Therefore they act as filters passing through (and even amplifying) some frequencies and attentuating others
Acoustic Resonance
bull And since they act as filters they have most of the same features of a filter even though we might use different names
bull Center frequency is often termed the resonant frequency
bull Frequency response curve often termed the resonance curve
Helmholtz Resonator
Actions of a Helmholtz Resonator
Stephen M Tasko
Other Acoustic Resonators Tube Resonators
bull Uniform tubes Factors that influence resonancendash Lengthndash Cross-sectional area along its lengthndash Whether it is closed at either or both ends
Uniform tube closed at one end
Uniform tube closed at one end
Stephen M Tasko
Uniform tube closed at one end
First resonance or formant
F1 = c4lWhere
c=speed of sound (35000 cmsec)l = length of the tube
males ~ 175 cmfemales ~ 14 cm
Higher resonantformant frequencies are odd multiples of F1
For examplebull F1 = (c4l )1
bull F2 = (c4l )3
bull F3 = (c4l )5
Comparing Helmholtz and tube resonators
Resonator Features
Sharply tuned Broadly tuned
Resonator Features
An example of the resonance characteristics of the human vocal tract
Frequency
Gain
SPPA 4030 Speech Science
Topic 1 The Speech Chain
The Speech Chain (Denes amp Pinson 1993)
What information is embedded in the speech signal
Branches of science employed to understand speech communication
Physical Quantities Review An Independent Learning Activity
Assignment 1
Topic 2 The Source-Filter Theory of Speech Production An Intr
Producing Speech
Source-Filter Theory of Speech Production
Vocal tract is a tube that can vary its shape
Source Filter Theory
Same Source Different Filter
Different Source Same Filters
Different Source Same Filters (Human)
Different Source Same Filters (Human) (2)
Different Source Same Filters (Human) (3)
Different Source Same Filters (Human) (4)
Different Source Same Filters (Non-Human)
Different Source Same Filters (Non-Human) (2)
Different Source Same Filters (Non-Human) If it quacks like a
Source Filter Theory Applied Alaryngeal Speech
Source-Filter Theory Applied Esophageal Insufflation Test
Source-Filter Theory Applied Tracheoesophageal (TE) Speech
Source Filter Theory Applied The Talkbox
Source-Filter Theory Applied The Talkbox
Topic 3 A Brief Review of Physical Acoustics
Spring Mass Model
What is sound
Sound-conducting media
Model of air molecule vibration (Time 1)
Model of air molecule vibration (Time 2)
Model of air molecule vibration (Time 3)
Model of air molecule vibration (Time 4)
Model of air molecule vibration (Time 5)
Model of air molecule vibration
Wave action of molecular motion
Amplitude waveform
Amplitude waveform (2)
Where is pressure in this model
Pressure waveform
Measuring Sound
Measuring Sound Signal Amplitude
Measuring Sound Signal Amplitude (2)
What units do we use to measure signal amplitude
Brief Review The decibel scale
Absolute vs relative measurement
Typical reference values
Howeverhellip
Linear vs logarithmic
Linear vs logarithmic (2)
Logarithmic Scale
Logarithmic Scale (2)
Combining the idea of logarithmic and relativehellip
Intensity vs Pressure
Extending the formula to pressure
Measuring Sound Frequencyperiod
Measuring Sound Frequencyperiod (2)
Phase Uniform Circular Motion
Initiating a sound waves that differ only in phase
Spatial variation in pressure wave
Spatial variation in pressure wave
Spatial variation in pressure wave (2)
Relation between frequency and wavelength
Learning Objectives
Graphic representation of sound
Same sound different graphs
Classification of sounds
Simple periodic sound
Simple periodic sound Graphic appearance
Complex periodic sounds
Complex periodic sounds Graphic appearance
Complex periodic sounds Graphic appearance (2)
Glottal Source
Amplitude vs Phase Spectrum
Amplitude vs Phase Spectrum (2)
(Complex) Aperiodic sounds
Aperiodic sounds Graphic appearance
Aperiodic sounds Graphic appearance (2)
Analysis of complex waves
Learning Objectives (2)
The ldquoenveloperdquo of a sound wave
Waveform envelope
Waveform envelope (2)
Spectrum envelope
Thought Question
Amplitude Spectrum Window Size
ldquoInstantaneousrdquo Amplitude Spectra
(Long Term) Average Amplitude Spectrum
Slide 90
Learning Objectives (3)
The Spectrogram
Building a spectrogram
Building a spectrogram
Building a spectrogram (2)
Two main types of spectrograms
Wide vs Narrow Band Spectrograms
Learning Objectives (4)
What is an ldquoAcousticrdquo Filter
Why might we be interested in filters
Kinds of frequency selective filters
Low Pass Filters
High Pass Filters
Band Pass Filter
Frequency Response Curve (FRC)
Operation of a filter on a signal
Learning Objectives (5)
Free vibration
Forced vibration
Forced vibration (2)
Resonance refers to
Back to the mass spring model
Acoustic Resonance
Acoustic Resonance (2)
Helmholtz Resonator
Actions of a Helmholtz Resonator
Other Acoustic Resonators Tube Resonators
Uniform tube closed at one end
Uniform tube closed at one end (2)
Uniform tube closed at one end
Comparing Helmholtz and tube resonators
Slide 122
Slide 123
Measuring Sound Signal Amplitude
Ways to measure itbull Instantaneousbull Peakbull Peak-to-peakbull Root mean square (RMS)bull Decibel ndashsee later
Time
Soun
d Pr
essu
re
+
-
0
Measuring Sound Signal Amplitude
bull Root mean square (RMS)
What units do we use to measure signal amplitude
bull Pressure Forceareabull Intensity = Powerarea where
power=worktime amp work=Forcedistancebull Intensity is proportionate to Pressure2
Brief Review The decibel scale
bull decibel scale typically used to represent signal amplitude
bull Many common measurement scales are absolute and linear
bull However the decibel scale is relative and logarithmic
Absolute vs relative measurement
bull Relative measures are a ratio of a measure to some reference
bull Relative scales can be referenced to anything you want
bull decibel scale doesnrsquot measure amplitude (intensity or pressure) absolutely but as a ratio of some reference value
Typical reference values
bull Intensityndash 10-12 wattsm2 ndash Threshold for normal hearing at 1000 Hz
bull Complex gt one frequency componentbull Aperiodic Does not repeat itselfbull Frequency components are not systematically
relatedbull May be ndash Continuousndash Transient
Aperiodic sounds Graphic appearance
bull Time domainndash no repeating pattern of pressure change
bull Frequency domainndash the spectrum is dense ndash No ldquopicket fencerdquo
bull Auditory impression sounds lsquonoisyrsquo
Aperiodic sounds Graphic appearance
From Hillenbrand
>
Analysis of complex wavesbull Waves can be summedbull Complex waves are the sum of simple wavesbull Fourier French Mathematician
ndash Any complex waveform may be formed by summing sinusoids of various frequency amplitude and phase
bull Fourier Analysisndash Provides a unique (only one) solution for a given sound signalndash Is reflected in the amplitude and phase spectrum of the signalndash Reveals the building blocks of complex waves which are sinusoids
Learning Objectives
bull Draw and differentiate the waveform and the waveform envelope
bull Draw and differentiate the amplitude spectrum the phase spectrum and the spectrum envelope
bull Differential between short-term spectra and long-term average spectra
The ldquoenveloperdquo of a sound wave
bull Waveform envelopendash imaginary smooth line that follows the peak of the
amplitude of a sound pressure waveformbull Spectrum envelopendash Imaginary smooth line drawn on top of the
amplitude spectrum
Waveform envelope
From Hillenbrand
Waveform envelope
Time
>
Spectrum envelope
Frequency
Ampl
itude
Thought Question
Can an aperiodic and complex periodic sound have identical
spectrum envelopes
Amplitude Spectrum Window Size
bull ldquoshort-termrdquo vs ldquolong-term averagerdquo amplitude spectrum
ldquoInstantaneousrdquo Amplitude Spectra
(Long Term) Average Amplitude Spectrum
Learning Objectivesbull Describe how the amplitude spectrum and the spectrogram are
relatedbull Identify the axis units of the spectrogrambull Provide some advantages of the spectrogram over the
amplitude spectrumbull Distinguish between a wide band and narrow band spectrogram
and outline the different information each providesbull Distinguish between a harmonic and a formant on a
spectrogrambull Be able to draw stylized (highly simplified) spectrograms based
on spectra and spectrum envelopes
The Spectrogram
Rotate90 degrees
F
AF
A
Building a spectrogram
Rotate it so thatThe amplitude isComing out of thepage
F
A This is really narrow because it is a slice in time
F
Time
Building a spectrogram
Dark bands= amplitudePeaks
Time
Freq
uenc
y
Building a spectrogram
Two main types of spectrograms
bull Narrow-band spectrogramsndash Akin to amplitude spectrums ldquolined uprdquondash Frequency resolution is really sharp
bull Wide-band spectrogramsndash Akin to spectrum envelopes ldquolined uprdquondash Frequency resolution not so sharp
Highlights harmonic structure
Highlights spectrum envelope
Wide vs Narrow Band Spectrograms
Learning Objectives
bull Define an acoustic filterbull Draw and label a frequency response curvebull Draw and differentiate different types of acoustic
filtersbull Define terms such as cutoff frequency center
frequency roll off rate gain and bandwidthbull Define and draw a basic filter system and relate that
to the source-filter theory of speech production
What is an ldquoAcousticrdquo Filter
bull holds back (attenuates) certain sounds and lets other sounds through - selective
Why might we be interested in filters
bull Human vocal tract acts like a frequency selective acoustic filter
bull Human auditory system behaves as a frequency selective filter
bull helps us understand how speech is produced and perceived
Kinds of frequency selective filters
Low-pass filtersndash Lets low frequencies ldquopass throughrdquo and attenuates high
frequencies
High-pass filtersndash Lets high frequencies ldquopass throughrdquo and attenuates low
frequencies
Band-pass filtersndash Lets a particular frequency range ldquopass throughrdquo and
attenuates other frequencies
Low Pass Filters
Frequencylow high
Gai
n
+
-
High Pass Filters
Frequencylow high
Gai
n
+
-
Band Pass Filter
Frequencylow high
Gai
n
+
-
Frequency Response Curve (FRC)
Frequencylow high
Gai
n
+
-
Center frequency
lower cutofffrequency
upper cutoff frequency
passband
3 dB
Operation of a filter on a signal
NOTE Amplitude spectrum describes a soundFrequency response curve describes a filter
Learning Objectivesbull Define resonance free and forced vibrationbull Describe how the pendulum and spring mass models can
help explain resonancebull Outline how mass and stiffness influences the resonant
frequency of a mass spring systembull Outline how acoustic resonators behave like acoustic filtersbull Calculate resonant frequencies of a uniform tube based on
its physical dimensionsbull Describe how the wavelength of the sound determines the
resonant frequency of tube
Free vibration
bull objects tend to vibrate at a characteristic or resonant frequency (RF)
Forced vibration
bull A vibrating system can force a nearby system into vibration
bull The efficiency with which this is accomplished is related to the similarity in the resonant frequency (RF) of the two systems
Forced vibration
bull If the RF of the two systems are the same the amplitude of forced vibration will be large
bull If the RF of the two systems are quite different the amplitude of forced vibration will be small or nonexistent
Resonance refers to
bull The tendency for an object to vibrate at a particular frequency or frequencies
bull The ability of a vibrating system to force another system into vibration
Back to the mass spring model
bull Vibratory frequency of the mass spring determined byndash Massndash Stiffness of the spring
httpphetcoloradoeduensimulationmass-spring-lab
Acoustic Resonance
bull Ideas from mechanical resonance also applies to acoustic systems
bull Acoustic chambers will transmit sound frequencies with more or less efficiency depending upon the physical characteristics
bull Therefore they act as filters passing through (and even amplifying) some frequencies and attentuating others
Acoustic Resonance
bull And since they act as filters they have most of the same features of a filter even though we might use different names
bull Center frequency is often termed the resonant frequency
bull Frequency response curve often termed the resonance curve
Helmholtz Resonator
Actions of a Helmholtz Resonator
Stephen M Tasko
Other Acoustic Resonators Tube Resonators
bull Uniform tubes Factors that influence resonancendash Lengthndash Cross-sectional area along its lengthndash Whether it is closed at either or both ends
Uniform tube closed at one end
Uniform tube closed at one end
Stephen M Tasko
Uniform tube closed at one end
First resonance or formant
F1 = c4lWhere
c=speed of sound (35000 cmsec)l = length of the tube
males ~ 175 cmfemales ~ 14 cm
Higher resonantformant frequencies are odd multiples of F1
For examplebull F1 = (c4l )1
bull F2 = (c4l )3
bull F3 = (c4l )5
Comparing Helmholtz and tube resonators
Resonator Features
Sharply tuned Broadly tuned
Resonator Features
An example of the resonance characteristics of the human vocal tract
Frequency
Gain
SPPA 4030 Speech Science
Topic 1 The Speech Chain
The Speech Chain (Denes amp Pinson 1993)
What information is embedded in the speech signal
Branches of science employed to understand speech communication
Physical Quantities Review An Independent Learning Activity
Assignment 1
Topic 2 The Source-Filter Theory of Speech Production An Intr
Producing Speech
Source-Filter Theory of Speech Production
Vocal tract is a tube that can vary its shape
Source Filter Theory
Same Source Different Filter
Different Source Same Filters
Different Source Same Filters (Human)
Different Source Same Filters (Human) (2)
Different Source Same Filters (Human) (3)
Different Source Same Filters (Human) (4)
Different Source Same Filters (Non-Human)
Different Source Same Filters (Non-Human) (2)
Different Source Same Filters (Non-Human) If it quacks like a
Source Filter Theory Applied Alaryngeal Speech
Source-Filter Theory Applied Esophageal Insufflation Test
Source-Filter Theory Applied Tracheoesophageal (TE) Speech
Source Filter Theory Applied The Talkbox
Source-Filter Theory Applied The Talkbox
Topic 3 A Brief Review of Physical Acoustics
Spring Mass Model
What is sound
Sound-conducting media
Model of air molecule vibration (Time 1)
Model of air molecule vibration (Time 2)
Model of air molecule vibration (Time 3)
Model of air molecule vibration (Time 4)
Model of air molecule vibration (Time 5)
Model of air molecule vibration
Wave action of molecular motion
Amplitude waveform
Amplitude waveform (2)
Where is pressure in this model
Pressure waveform
Measuring Sound
Measuring Sound Signal Amplitude
Measuring Sound Signal Amplitude (2)
What units do we use to measure signal amplitude
Brief Review The decibel scale
Absolute vs relative measurement
Typical reference values
Howeverhellip
Linear vs logarithmic
Linear vs logarithmic (2)
Logarithmic Scale
Logarithmic Scale (2)
Combining the idea of logarithmic and relativehellip
Intensity vs Pressure
Extending the formula to pressure
Measuring Sound Frequencyperiod
Measuring Sound Frequencyperiod (2)
Phase Uniform Circular Motion
Initiating a sound waves that differ only in phase
Spatial variation in pressure wave
Spatial variation in pressure wave
Spatial variation in pressure wave (2)
Relation between frequency and wavelength
Learning Objectives
Graphic representation of sound
Same sound different graphs
Classification of sounds
Simple periodic sound
Simple periodic sound Graphic appearance
Complex periodic sounds
Complex periodic sounds Graphic appearance
Complex periodic sounds Graphic appearance (2)
Glottal Source
Amplitude vs Phase Spectrum
Amplitude vs Phase Spectrum (2)
(Complex) Aperiodic sounds
Aperiodic sounds Graphic appearance
Aperiodic sounds Graphic appearance (2)
Analysis of complex waves
Learning Objectives (2)
The ldquoenveloperdquo of a sound wave
Waveform envelope
Waveform envelope (2)
Spectrum envelope
Thought Question
Amplitude Spectrum Window Size
ldquoInstantaneousrdquo Amplitude Spectra
(Long Term) Average Amplitude Spectrum
Slide 90
Learning Objectives (3)
The Spectrogram
Building a spectrogram
Building a spectrogram
Building a spectrogram (2)
Two main types of spectrograms
Wide vs Narrow Band Spectrograms
Learning Objectives (4)
What is an ldquoAcousticrdquo Filter
Why might we be interested in filters
Kinds of frequency selective filters
Low Pass Filters
High Pass Filters
Band Pass Filter
Frequency Response Curve (FRC)
Operation of a filter on a signal
Learning Objectives (5)
Free vibration
Forced vibration
Forced vibration (2)
Resonance refers to
Back to the mass spring model
Acoustic Resonance
Acoustic Resonance (2)
Helmholtz Resonator
Actions of a Helmholtz Resonator
Other Acoustic Resonators Tube Resonators
Uniform tube closed at one end
Uniform tube closed at one end (2)
Uniform tube closed at one end
Comparing Helmholtz and tube resonators
Slide 122
Slide 123
Measuring Sound Signal Amplitude
bull Root mean square (RMS)
What units do we use to measure signal amplitude
bull Pressure Forceareabull Intensity = Powerarea where
power=worktime amp work=Forcedistancebull Intensity is proportionate to Pressure2
Brief Review The decibel scale
bull decibel scale typically used to represent signal amplitude
bull Many common measurement scales are absolute and linear
bull However the decibel scale is relative and logarithmic
Absolute vs relative measurement
bull Relative measures are a ratio of a measure to some reference
bull Relative scales can be referenced to anything you want
bull decibel scale doesnrsquot measure amplitude (intensity or pressure) absolutely but as a ratio of some reference value
Typical reference values
bull Intensityndash 10-12 wattsm2 ndash Threshold for normal hearing at 1000 Hz
bull Complex gt one frequency componentbull Aperiodic Does not repeat itselfbull Frequency components are not systematically
relatedbull May be ndash Continuousndash Transient
Aperiodic sounds Graphic appearance
bull Time domainndash no repeating pattern of pressure change
bull Frequency domainndash the spectrum is dense ndash No ldquopicket fencerdquo
bull Auditory impression sounds lsquonoisyrsquo
Aperiodic sounds Graphic appearance
From Hillenbrand
>
Analysis of complex wavesbull Waves can be summedbull Complex waves are the sum of simple wavesbull Fourier French Mathematician
ndash Any complex waveform may be formed by summing sinusoids of various frequency amplitude and phase
bull Fourier Analysisndash Provides a unique (only one) solution for a given sound signalndash Is reflected in the amplitude and phase spectrum of the signalndash Reveals the building blocks of complex waves which are sinusoids
Learning Objectives
bull Draw and differentiate the waveform and the waveform envelope
bull Draw and differentiate the amplitude spectrum the phase spectrum and the spectrum envelope
bull Differential between short-term spectra and long-term average spectra
The ldquoenveloperdquo of a sound wave
bull Waveform envelopendash imaginary smooth line that follows the peak of the
amplitude of a sound pressure waveformbull Spectrum envelopendash Imaginary smooth line drawn on top of the
amplitude spectrum
Waveform envelope
From Hillenbrand
Waveform envelope
Time
>
Spectrum envelope
Frequency
Ampl
itude
Thought Question
Can an aperiodic and complex periodic sound have identical
spectrum envelopes
Amplitude Spectrum Window Size
bull ldquoshort-termrdquo vs ldquolong-term averagerdquo amplitude spectrum
ldquoInstantaneousrdquo Amplitude Spectra
(Long Term) Average Amplitude Spectrum
Learning Objectivesbull Describe how the amplitude spectrum and the spectrogram are
relatedbull Identify the axis units of the spectrogrambull Provide some advantages of the spectrogram over the
amplitude spectrumbull Distinguish between a wide band and narrow band spectrogram
and outline the different information each providesbull Distinguish between a harmonic and a formant on a
spectrogrambull Be able to draw stylized (highly simplified) spectrograms based
on spectra and spectrum envelopes
The Spectrogram
Rotate90 degrees
F
AF
A
Building a spectrogram
Rotate it so thatThe amplitude isComing out of thepage
F
A This is really narrow because it is a slice in time
F
Time
Building a spectrogram
Dark bands= amplitudePeaks
Time
Freq
uenc
y
Building a spectrogram
Two main types of spectrograms
bull Narrow-band spectrogramsndash Akin to amplitude spectrums ldquolined uprdquondash Frequency resolution is really sharp
bull Wide-band spectrogramsndash Akin to spectrum envelopes ldquolined uprdquondash Frequency resolution not so sharp
Highlights harmonic structure
Highlights spectrum envelope
Wide vs Narrow Band Spectrograms
Learning Objectives
bull Define an acoustic filterbull Draw and label a frequency response curvebull Draw and differentiate different types of acoustic
filtersbull Define terms such as cutoff frequency center
frequency roll off rate gain and bandwidthbull Define and draw a basic filter system and relate that
to the source-filter theory of speech production
What is an ldquoAcousticrdquo Filter
bull holds back (attenuates) certain sounds and lets other sounds through - selective
Why might we be interested in filters
bull Human vocal tract acts like a frequency selective acoustic filter
bull Human auditory system behaves as a frequency selective filter
bull helps us understand how speech is produced and perceived
Kinds of frequency selective filters
Low-pass filtersndash Lets low frequencies ldquopass throughrdquo and attenuates high
frequencies
High-pass filtersndash Lets high frequencies ldquopass throughrdquo and attenuates low
frequencies
Band-pass filtersndash Lets a particular frequency range ldquopass throughrdquo and
attenuates other frequencies
Low Pass Filters
Frequencylow high
Gai
n
+
-
High Pass Filters
Frequencylow high
Gai
n
+
-
Band Pass Filter
Frequencylow high
Gai
n
+
-
Frequency Response Curve (FRC)
Frequencylow high
Gai
n
+
-
Center frequency
lower cutofffrequency
upper cutoff frequency
passband
3 dB
Operation of a filter on a signal
NOTE Amplitude spectrum describes a soundFrequency response curve describes a filter
Learning Objectivesbull Define resonance free and forced vibrationbull Describe how the pendulum and spring mass models can
help explain resonancebull Outline how mass and stiffness influences the resonant
frequency of a mass spring systembull Outline how acoustic resonators behave like acoustic filtersbull Calculate resonant frequencies of a uniform tube based on
its physical dimensionsbull Describe how the wavelength of the sound determines the
resonant frequency of tube
Free vibration
bull objects tend to vibrate at a characteristic or resonant frequency (RF)
Forced vibration
bull A vibrating system can force a nearby system into vibration
bull The efficiency with which this is accomplished is related to the similarity in the resonant frequency (RF) of the two systems
Forced vibration
bull If the RF of the two systems are the same the amplitude of forced vibration will be large
bull If the RF of the two systems are quite different the amplitude of forced vibration will be small or nonexistent
Resonance refers to
bull The tendency for an object to vibrate at a particular frequency or frequencies
bull The ability of a vibrating system to force another system into vibration
Back to the mass spring model
bull Vibratory frequency of the mass spring determined byndash Massndash Stiffness of the spring
httpphetcoloradoeduensimulationmass-spring-lab
Acoustic Resonance
bull Ideas from mechanical resonance also applies to acoustic systems
bull Acoustic chambers will transmit sound frequencies with more or less efficiency depending upon the physical characteristics
bull Therefore they act as filters passing through (and even amplifying) some frequencies and attentuating others
Acoustic Resonance
bull And since they act as filters they have most of the same features of a filter even though we might use different names
bull Center frequency is often termed the resonant frequency
bull Frequency response curve often termed the resonance curve
Helmholtz Resonator
Actions of a Helmholtz Resonator
Stephen M Tasko
Other Acoustic Resonators Tube Resonators
bull Uniform tubes Factors that influence resonancendash Lengthndash Cross-sectional area along its lengthndash Whether it is closed at either or both ends
Uniform tube closed at one end
Uniform tube closed at one end
Stephen M Tasko
Uniform tube closed at one end
First resonance or formant
F1 = c4lWhere
c=speed of sound (35000 cmsec)l = length of the tube
males ~ 175 cmfemales ~ 14 cm
Higher resonantformant frequencies are odd multiples of F1
For examplebull F1 = (c4l )1
bull F2 = (c4l )3
bull F3 = (c4l )5
Comparing Helmholtz and tube resonators
Resonator Features
Sharply tuned Broadly tuned
Resonator Features
An example of the resonance characteristics of the human vocal tract
Frequency
Gain
SPPA 4030 Speech Science
Topic 1 The Speech Chain
The Speech Chain (Denes amp Pinson 1993)
What information is embedded in the speech signal
Branches of science employed to understand speech communication
Physical Quantities Review An Independent Learning Activity
Assignment 1
Topic 2 The Source-Filter Theory of Speech Production An Intr
Producing Speech
Source-Filter Theory of Speech Production
Vocal tract is a tube that can vary its shape
Source Filter Theory
Same Source Different Filter
Different Source Same Filters
Different Source Same Filters (Human)
Different Source Same Filters (Human) (2)
Different Source Same Filters (Human) (3)
Different Source Same Filters (Human) (4)
Different Source Same Filters (Non-Human)
Different Source Same Filters (Non-Human) (2)
Different Source Same Filters (Non-Human) If it quacks like a
Source Filter Theory Applied Alaryngeal Speech
Source-Filter Theory Applied Esophageal Insufflation Test
Source-Filter Theory Applied Tracheoesophageal (TE) Speech
Source Filter Theory Applied The Talkbox
Source-Filter Theory Applied The Talkbox
Topic 3 A Brief Review of Physical Acoustics
Spring Mass Model
What is sound
Sound-conducting media
Model of air molecule vibration (Time 1)
Model of air molecule vibration (Time 2)
Model of air molecule vibration (Time 3)
Model of air molecule vibration (Time 4)
Model of air molecule vibration (Time 5)
Model of air molecule vibration
Wave action of molecular motion
Amplitude waveform
Amplitude waveform (2)
Where is pressure in this model
Pressure waveform
Measuring Sound
Measuring Sound Signal Amplitude
Measuring Sound Signal Amplitude (2)
What units do we use to measure signal amplitude
Brief Review The decibel scale
Absolute vs relative measurement
Typical reference values
Howeverhellip
Linear vs logarithmic
Linear vs logarithmic (2)
Logarithmic Scale
Logarithmic Scale (2)
Combining the idea of logarithmic and relativehellip
Intensity vs Pressure
Extending the formula to pressure
Measuring Sound Frequencyperiod
Measuring Sound Frequencyperiod (2)
Phase Uniform Circular Motion
Initiating a sound waves that differ only in phase
Spatial variation in pressure wave
Spatial variation in pressure wave
Spatial variation in pressure wave (2)
Relation between frequency and wavelength
Learning Objectives
Graphic representation of sound
Same sound different graphs
Classification of sounds
Simple periodic sound
Simple periodic sound Graphic appearance
Complex periodic sounds
Complex periodic sounds Graphic appearance
Complex periodic sounds Graphic appearance (2)
Glottal Source
Amplitude vs Phase Spectrum
Amplitude vs Phase Spectrum (2)
(Complex) Aperiodic sounds
Aperiodic sounds Graphic appearance
Aperiodic sounds Graphic appearance (2)
Analysis of complex waves
Learning Objectives (2)
The ldquoenveloperdquo of a sound wave
Waveform envelope
Waveform envelope (2)
Spectrum envelope
Thought Question
Amplitude Spectrum Window Size
ldquoInstantaneousrdquo Amplitude Spectra
(Long Term) Average Amplitude Spectrum
Slide 90
Learning Objectives (3)
The Spectrogram
Building a spectrogram
Building a spectrogram
Building a spectrogram (2)
Two main types of spectrograms
Wide vs Narrow Band Spectrograms
Learning Objectives (4)
What is an ldquoAcousticrdquo Filter
Why might we be interested in filters
Kinds of frequency selective filters
Low Pass Filters
High Pass Filters
Band Pass Filter
Frequency Response Curve (FRC)
Operation of a filter on a signal
Learning Objectives (5)
Free vibration
Forced vibration
Forced vibration (2)
Resonance refers to
Back to the mass spring model
Acoustic Resonance
Acoustic Resonance (2)
Helmholtz Resonator
Actions of a Helmholtz Resonator
Other Acoustic Resonators Tube Resonators
Uniform tube closed at one end
Uniform tube closed at one end (2)
Uniform tube closed at one end
Comparing Helmholtz and tube resonators
Slide 122
Slide 123
What units do we use to measure signal amplitude
bull Pressure Forceareabull Intensity = Powerarea where
power=worktime amp work=Forcedistancebull Intensity is proportionate to Pressure2
Brief Review The decibel scale
bull decibel scale typically used to represent signal amplitude
bull Many common measurement scales are absolute and linear
bull However the decibel scale is relative and logarithmic
Absolute vs relative measurement
bull Relative measures are a ratio of a measure to some reference
bull Relative scales can be referenced to anything you want
bull decibel scale doesnrsquot measure amplitude (intensity or pressure) absolutely but as a ratio of some reference value
Typical reference values
bull Intensityndash 10-12 wattsm2 ndash Threshold for normal hearing at 1000 Hz
bull Complex gt one frequency componentbull Aperiodic Does not repeat itselfbull Frequency components are not systematically
relatedbull May be ndash Continuousndash Transient
Aperiodic sounds Graphic appearance
bull Time domainndash no repeating pattern of pressure change
bull Frequency domainndash the spectrum is dense ndash No ldquopicket fencerdquo
bull Auditory impression sounds lsquonoisyrsquo
Aperiodic sounds Graphic appearance
From Hillenbrand
>
Analysis of complex wavesbull Waves can be summedbull Complex waves are the sum of simple wavesbull Fourier French Mathematician
ndash Any complex waveform may be formed by summing sinusoids of various frequency amplitude and phase
bull Fourier Analysisndash Provides a unique (only one) solution for a given sound signalndash Is reflected in the amplitude and phase spectrum of the signalndash Reveals the building blocks of complex waves which are sinusoids
Learning Objectives
bull Draw and differentiate the waveform and the waveform envelope
bull Draw and differentiate the amplitude spectrum the phase spectrum and the spectrum envelope
bull Differential between short-term spectra and long-term average spectra
The ldquoenveloperdquo of a sound wave
bull Waveform envelopendash imaginary smooth line that follows the peak of the
amplitude of a sound pressure waveformbull Spectrum envelopendash Imaginary smooth line drawn on top of the
amplitude spectrum
Waveform envelope
From Hillenbrand
Waveform envelope
Time
>
Spectrum envelope
Frequency
Ampl
itude
Thought Question
Can an aperiodic and complex periodic sound have identical
spectrum envelopes
Amplitude Spectrum Window Size
bull ldquoshort-termrdquo vs ldquolong-term averagerdquo amplitude spectrum
ldquoInstantaneousrdquo Amplitude Spectra
(Long Term) Average Amplitude Spectrum
Learning Objectivesbull Describe how the amplitude spectrum and the spectrogram are
relatedbull Identify the axis units of the spectrogrambull Provide some advantages of the spectrogram over the
amplitude spectrumbull Distinguish between a wide band and narrow band spectrogram
and outline the different information each providesbull Distinguish between a harmonic and a formant on a
spectrogrambull Be able to draw stylized (highly simplified) spectrograms based
on spectra and spectrum envelopes
The Spectrogram
Rotate90 degrees
F
AF
A
Building a spectrogram
Rotate it so thatThe amplitude isComing out of thepage
F
A This is really narrow because it is a slice in time
F
Time
Building a spectrogram
Dark bands= amplitudePeaks
Time
Freq
uenc
y
Building a spectrogram
Two main types of spectrograms
bull Narrow-band spectrogramsndash Akin to amplitude spectrums ldquolined uprdquondash Frequency resolution is really sharp
bull Wide-band spectrogramsndash Akin to spectrum envelopes ldquolined uprdquondash Frequency resolution not so sharp
Highlights harmonic structure
Highlights spectrum envelope
Wide vs Narrow Band Spectrograms
Learning Objectives
bull Define an acoustic filterbull Draw and label a frequency response curvebull Draw and differentiate different types of acoustic
filtersbull Define terms such as cutoff frequency center
frequency roll off rate gain and bandwidthbull Define and draw a basic filter system and relate that
to the source-filter theory of speech production
What is an ldquoAcousticrdquo Filter
bull holds back (attenuates) certain sounds and lets other sounds through - selective
Why might we be interested in filters
bull Human vocal tract acts like a frequency selective acoustic filter
bull Human auditory system behaves as a frequency selective filter
bull helps us understand how speech is produced and perceived
Kinds of frequency selective filters
Low-pass filtersndash Lets low frequencies ldquopass throughrdquo and attenuates high
frequencies
High-pass filtersndash Lets high frequencies ldquopass throughrdquo and attenuates low
frequencies
Band-pass filtersndash Lets a particular frequency range ldquopass throughrdquo and
attenuates other frequencies
Low Pass Filters
Frequencylow high
Gai
n
+
-
High Pass Filters
Frequencylow high
Gai
n
+
-
Band Pass Filter
Frequencylow high
Gai
n
+
-
Frequency Response Curve (FRC)
Frequencylow high
Gai
n
+
-
Center frequency
lower cutofffrequency
upper cutoff frequency
passband
3 dB
Operation of a filter on a signal
NOTE Amplitude spectrum describes a soundFrequency response curve describes a filter
Learning Objectivesbull Define resonance free and forced vibrationbull Describe how the pendulum and spring mass models can
help explain resonancebull Outline how mass and stiffness influences the resonant
frequency of a mass spring systembull Outline how acoustic resonators behave like acoustic filtersbull Calculate resonant frequencies of a uniform tube based on
its physical dimensionsbull Describe how the wavelength of the sound determines the
resonant frequency of tube
Free vibration
bull objects tend to vibrate at a characteristic or resonant frequency (RF)
Forced vibration
bull A vibrating system can force a nearby system into vibration
bull The efficiency with which this is accomplished is related to the similarity in the resonant frequency (RF) of the two systems
Forced vibration
bull If the RF of the two systems are the same the amplitude of forced vibration will be large
bull If the RF of the two systems are quite different the amplitude of forced vibration will be small or nonexistent
Resonance refers to
bull The tendency for an object to vibrate at a particular frequency or frequencies
bull The ability of a vibrating system to force another system into vibration
Back to the mass spring model
bull Vibratory frequency of the mass spring determined byndash Massndash Stiffness of the spring
httpphetcoloradoeduensimulationmass-spring-lab
Acoustic Resonance
bull Ideas from mechanical resonance also applies to acoustic systems
bull Acoustic chambers will transmit sound frequencies with more or less efficiency depending upon the physical characteristics
bull Therefore they act as filters passing through (and even amplifying) some frequencies and attentuating others
Acoustic Resonance
bull And since they act as filters they have most of the same features of a filter even though we might use different names
bull Center frequency is often termed the resonant frequency
bull Frequency response curve often termed the resonance curve
Helmholtz Resonator
Actions of a Helmholtz Resonator
Stephen M Tasko
Other Acoustic Resonators Tube Resonators
bull Uniform tubes Factors that influence resonancendash Lengthndash Cross-sectional area along its lengthndash Whether it is closed at either or both ends
Uniform tube closed at one end
Uniform tube closed at one end
Stephen M Tasko
Uniform tube closed at one end
First resonance or formant
F1 = c4lWhere
c=speed of sound (35000 cmsec)l = length of the tube
males ~ 175 cmfemales ~ 14 cm
Higher resonantformant frequencies are odd multiples of F1
For examplebull F1 = (c4l )1
bull F2 = (c4l )3
bull F3 = (c4l )5
Comparing Helmholtz and tube resonators
Resonator Features
Sharply tuned Broadly tuned
Resonator Features
An example of the resonance characteristics of the human vocal tract
Frequency
Gain
SPPA 4030 Speech Science
Topic 1 The Speech Chain
The Speech Chain (Denes amp Pinson 1993)
What information is embedded in the speech signal
Branches of science employed to understand speech communication
Physical Quantities Review An Independent Learning Activity
Assignment 1
Topic 2 The Source-Filter Theory of Speech Production An Intr
Producing Speech
Source-Filter Theory of Speech Production
Vocal tract is a tube that can vary its shape
Source Filter Theory
Same Source Different Filter
Different Source Same Filters
Different Source Same Filters (Human)
Different Source Same Filters (Human) (2)
Different Source Same Filters (Human) (3)
Different Source Same Filters (Human) (4)
Different Source Same Filters (Non-Human)
Different Source Same Filters (Non-Human) (2)
Different Source Same Filters (Non-Human) If it quacks like a
Source Filter Theory Applied Alaryngeal Speech
Source-Filter Theory Applied Esophageal Insufflation Test
Source-Filter Theory Applied Tracheoesophageal (TE) Speech
Source Filter Theory Applied The Talkbox
Source-Filter Theory Applied The Talkbox
Topic 3 A Brief Review of Physical Acoustics
Spring Mass Model
What is sound
Sound-conducting media
Model of air molecule vibration (Time 1)
Model of air molecule vibration (Time 2)
Model of air molecule vibration (Time 3)
Model of air molecule vibration (Time 4)
Model of air molecule vibration (Time 5)
Model of air molecule vibration
Wave action of molecular motion
Amplitude waveform
Amplitude waveform (2)
Where is pressure in this model
Pressure waveform
Measuring Sound
Measuring Sound Signal Amplitude
Measuring Sound Signal Amplitude (2)
What units do we use to measure signal amplitude
Brief Review The decibel scale
Absolute vs relative measurement
Typical reference values
Howeverhellip
Linear vs logarithmic
Linear vs logarithmic (2)
Logarithmic Scale
Logarithmic Scale (2)
Combining the idea of logarithmic and relativehellip
Intensity vs Pressure
Extending the formula to pressure
Measuring Sound Frequencyperiod
Measuring Sound Frequencyperiod (2)
Phase Uniform Circular Motion
Initiating a sound waves that differ only in phase
Spatial variation in pressure wave
Spatial variation in pressure wave
Spatial variation in pressure wave (2)
Relation between frequency and wavelength
Learning Objectives
Graphic representation of sound
Same sound different graphs
Classification of sounds
Simple periodic sound
Simple periodic sound Graphic appearance
Complex periodic sounds
Complex periodic sounds Graphic appearance
Complex periodic sounds Graphic appearance (2)
Glottal Source
Amplitude vs Phase Spectrum
Amplitude vs Phase Spectrum (2)
(Complex) Aperiodic sounds
Aperiodic sounds Graphic appearance
Aperiodic sounds Graphic appearance (2)
Analysis of complex waves
Learning Objectives (2)
The ldquoenveloperdquo of a sound wave
Waveform envelope
Waveform envelope (2)
Spectrum envelope
Thought Question
Amplitude Spectrum Window Size
ldquoInstantaneousrdquo Amplitude Spectra
(Long Term) Average Amplitude Spectrum
Slide 90
Learning Objectives (3)
The Spectrogram
Building a spectrogram
Building a spectrogram
Building a spectrogram (2)
Two main types of spectrograms
Wide vs Narrow Band Spectrograms
Learning Objectives (4)
What is an ldquoAcousticrdquo Filter
Why might we be interested in filters
Kinds of frequency selective filters
Low Pass Filters
High Pass Filters
Band Pass Filter
Frequency Response Curve (FRC)
Operation of a filter on a signal
Learning Objectives (5)
Free vibration
Forced vibration
Forced vibration (2)
Resonance refers to
Back to the mass spring model
Acoustic Resonance
Acoustic Resonance (2)
Helmholtz Resonator
Actions of a Helmholtz Resonator
Other Acoustic Resonators Tube Resonators
Uniform tube closed at one end
Uniform tube closed at one end (2)
Uniform tube closed at one end
Comparing Helmholtz and tube resonators
Slide 122
Slide 123
Brief Review The decibel scale
bull decibel scale typically used to represent signal amplitude
bull Many common measurement scales are absolute and linear
bull However the decibel scale is relative and logarithmic
Absolute vs relative measurement
bull Relative measures are a ratio of a measure to some reference
bull Relative scales can be referenced to anything you want
bull decibel scale doesnrsquot measure amplitude (intensity or pressure) absolutely but as a ratio of some reference value
Typical reference values
bull Intensityndash 10-12 wattsm2 ndash Threshold for normal hearing at 1000 Hz
bull Complex gt one frequency componentbull Aperiodic Does not repeat itselfbull Frequency components are not systematically
relatedbull May be ndash Continuousndash Transient
Aperiodic sounds Graphic appearance
bull Time domainndash no repeating pattern of pressure change
bull Frequency domainndash the spectrum is dense ndash No ldquopicket fencerdquo
bull Auditory impression sounds lsquonoisyrsquo
Aperiodic sounds Graphic appearance
From Hillenbrand
>
Analysis of complex wavesbull Waves can be summedbull Complex waves are the sum of simple wavesbull Fourier French Mathematician
ndash Any complex waveform may be formed by summing sinusoids of various frequency amplitude and phase
bull Fourier Analysisndash Provides a unique (only one) solution for a given sound signalndash Is reflected in the amplitude and phase spectrum of the signalndash Reveals the building blocks of complex waves which are sinusoids
Learning Objectives
bull Draw and differentiate the waveform and the waveform envelope
bull Draw and differentiate the amplitude spectrum the phase spectrum and the spectrum envelope
bull Differential between short-term spectra and long-term average spectra
The ldquoenveloperdquo of a sound wave
bull Waveform envelopendash imaginary smooth line that follows the peak of the
amplitude of a sound pressure waveformbull Spectrum envelopendash Imaginary smooth line drawn on top of the
amplitude spectrum
Waveform envelope
From Hillenbrand
Waveform envelope
Time
>
Spectrum envelope
Frequency
Ampl
itude
Thought Question
Can an aperiodic and complex periodic sound have identical
spectrum envelopes
Amplitude Spectrum Window Size
bull ldquoshort-termrdquo vs ldquolong-term averagerdquo amplitude spectrum
ldquoInstantaneousrdquo Amplitude Spectra
(Long Term) Average Amplitude Spectrum
Learning Objectivesbull Describe how the amplitude spectrum and the spectrogram are
relatedbull Identify the axis units of the spectrogrambull Provide some advantages of the spectrogram over the
amplitude spectrumbull Distinguish between a wide band and narrow band spectrogram
and outline the different information each providesbull Distinguish between a harmonic and a formant on a
spectrogrambull Be able to draw stylized (highly simplified) spectrograms based
on spectra and spectrum envelopes
The Spectrogram
Rotate90 degrees
F
AF
A
Building a spectrogram
Rotate it so thatThe amplitude isComing out of thepage
F
A This is really narrow because it is a slice in time
F
Time
Building a spectrogram
Dark bands= amplitudePeaks
Time
Freq
uenc
y
Building a spectrogram
Two main types of spectrograms
bull Narrow-band spectrogramsndash Akin to amplitude spectrums ldquolined uprdquondash Frequency resolution is really sharp
bull Wide-band spectrogramsndash Akin to spectrum envelopes ldquolined uprdquondash Frequency resolution not so sharp
Highlights harmonic structure
Highlights spectrum envelope
Wide vs Narrow Band Spectrograms
Learning Objectives
bull Define an acoustic filterbull Draw and label a frequency response curvebull Draw and differentiate different types of acoustic
filtersbull Define terms such as cutoff frequency center
frequency roll off rate gain and bandwidthbull Define and draw a basic filter system and relate that
to the source-filter theory of speech production
What is an ldquoAcousticrdquo Filter
bull holds back (attenuates) certain sounds and lets other sounds through - selective
Why might we be interested in filters
bull Human vocal tract acts like a frequency selective acoustic filter
bull Human auditory system behaves as a frequency selective filter
bull helps us understand how speech is produced and perceived
Kinds of frequency selective filters
Low-pass filtersndash Lets low frequencies ldquopass throughrdquo and attenuates high
frequencies
High-pass filtersndash Lets high frequencies ldquopass throughrdquo and attenuates low
frequencies
Band-pass filtersndash Lets a particular frequency range ldquopass throughrdquo and
attenuates other frequencies
Low Pass Filters
Frequencylow high
Gai
n
+
-
High Pass Filters
Frequencylow high
Gai
n
+
-
Band Pass Filter
Frequencylow high
Gai
n
+
-
Frequency Response Curve (FRC)
Frequencylow high
Gai
n
+
-
Center frequency
lower cutofffrequency
upper cutoff frequency
passband
3 dB
Operation of a filter on a signal
NOTE Amplitude spectrum describes a soundFrequency response curve describes a filter
Learning Objectivesbull Define resonance free and forced vibrationbull Describe how the pendulum and spring mass models can
help explain resonancebull Outline how mass and stiffness influences the resonant
frequency of a mass spring systembull Outline how acoustic resonators behave like acoustic filtersbull Calculate resonant frequencies of a uniform tube based on
its physical dimensionsbull Describe how the wavelength of the sound determines the
resonant frequency of tube
Free vibration
bull objects tend to vibrate at a characteristic or resonant frequency (RF)
Forced vibration
bull A vibrating system can force a nearby system into vibration
bull The efficiency with which this is accomplished is related to the similarity in the resonant frequency (RF) of the two systems
Forced vibration
bull If the RF of the two systems are the same the amplitude of forced vibration will be large
bull If the RF of the two systems are quite different the amplitude of forced vibration will be small or nonexistent
Resonance refers to
bull The tendency for an object to vibrate at a particular frequency or frequencies
bull The ability of a vibrating system to force another system into vibration
Back to the mass spring model
bull Vibratory frequency of the mass spring determined byndash Massndash Stiffness of the spring
httpphetcoloradoeduensimulationmass-spring-lab
Acoustic Resonance
bull Ideas from mechanical resonance also applies to acoustic systems
bull Acoustic chambers will transmit sound frequencies with more or less efficiency depending upon the physical characteristics
bull Therefore they act as filters passing through (and even amplifying) some frequencies and attentuating others
Acoustic Resonance
bull And since they act as filters they have most of the same features of a filter even though we might use different names
bull Center frequency is often termed the resonant frequency
bull Frequency response curve often termed the resonance curve
Helmholtz Resonator
Actions of a Helmholtz Resonator
Stephen M Tasko
Other Acoustic Resonators Tube Resonators
bull Uniform tubes Factors that influence resonancendash Lengthndash Cross-sectional area along its lengthndash Whether it is closed at either or both ends
Uniform tube closed at one end
Uniform tube closed at one end
Stephen M Tasko
Uniform tube closed at one end
First resonance or formant
F1 = c4lWhere
c=speed of sound (35000 cmsec)l = length of the tube
males ~ 175 cmfemales ~ 14 cm
Higher resonantformant frequencies are odd multiples of F1
For examplebull F1 = (c4l )1
bull F2 = (c4l )3
bull F3 = (c4l )5
Comparing Helmholtz and tube resonators
Resonator Features
Sharply tuned Broadly tuned
Resonator Features
An example of the resonance characteristics of the human vocal tract
Frequency
Gain
SPPA 4030 Speech Science
Topic 1 The Speech Chain
The Speech Chain (Denes amp Pinson 1993)
What information is embedded in the speech signal
Branches of science employed to understand speech communication
Physical Quantities Review An Independent Learning Activity
Assignment 1
Topic 2 The Source-Filter Theory of Speech Production An Intr
Producing Speech
Source-Filter Theory of Speech Production
Vocal tract is a tube that can vary its shape
Source Filter Theory
Same Source Different Filter
Different Source Same Filters
Different Source Same Filters (Human)
Different Source Same Filters (Human) (2)
Different Source Same Filters (Human) (3)
Different Source Same Filters (Human) (4)
Different Source Same Filters (Non-Human)
Different Source Same Filters (Non-Human) (2)
Different Source Same Filters (Non-Human) If it quacks like a
Source Filter Theory Applied Alaryngeal Speech
Source-Filter Theory Applied Esophageal Insufflation Test
Source-Filter Theory Applied Tracheoesophageal (TE) Speech
Source Filter Theory Applied The Talkbox
Source-Filter Theory Applied The Talkbox
Topic 3 A Brief Review of Physical Acoustics
Spring Mass Model
What is sound
Sound-conducting media
Model of air molecule vibration (Time 1)
Model of air molecule vibration (Time 2)
Model of air molecule vibration (Time 3)
Model of air molecule vibration (Time 4)
Model of air molecule vibration (Time 5)
Model of air molecule vibration
Wave action of molecular motion
Amplitude waveform
Amplitude waveform (2)
Where is pressure in this model
Pressure waveform
Measuring Sound
Measuring Sound Signal Amplitude
Measuring Sound Signal Amplitude (2)
What units do we use to measure signal amplitude
Brief Review The decibel scale
Absolute vs relative measurement
Typical reference values
Howeverhellip
Linear vs logarithmic
Linear vs logarithmic (2)
Logarithmic Scale
Logarithmic Scale (2)
Combining the idea of logarithmic and relativehellip
Intensity vs Pressure
Extending the formula to pressure
Measuring Sound Frequencyperiod
Measuring Sound Frequencyperiod (2)
Phase Uniform Circular Motion
Initiating a sound waves that differ only in phase
Spatial variation in pressure wave
Spatial variation in pressure wave
Spatial variation in pressure wave (2)
Relation between frequency and wavelength
Learning Objectives
Graphic representation of sound
Same sound different graphs
Classification of sounds
Simple periodic sound
Simple periodic sound Graphic appearance
Complex periodic sounds
Complex periodic sounds Graphic appearance
Complex periodic sounds Graphic appearance (2)
Glottal Source
Amplitude vs Phase Spectrum
Amplitude vs Phase Spectrum (2)
(Complex) Aperiodic sounds
Aperiodic sounds Graphic appearance
Aperiodic sounds Graphic appearance (2)
Analysis of complex waves
Learning Objectives (2)
The ldquoenveloperdquo of a sound wave
Waveform envelope
Waveform envelope (2)
Spectrum envelope
Thought Question
Amplitude Spectrum Window Size
ldquoInstantaneousrdquo Amplitude Spectra
(Long Term) Average Amplitude Spectrum
Slide 90
Learning Objectives (3)
The Spectrogram
Building a spectrogram
Building a spectrogram
Building a spectrogram (2)
Two main types of spectrograms
Wide vs Narrow Band Spectrograms
Learning Objectives (4)
What is an ldquoAcousticrdquo Filter
Why might we be interested in filters
Kinds of frequency selective filters
Low Pass Filters
High Pass Filters
Band Pass Filter
Frequency Response Curve (FRC)
Operation of a filter on a signal
Learning Objectives (5)
Free vibration
Forced vibration
Forced vibration (2)
Resonance refers to
Back to the mass spring model
Acoustic Resonance
Acoustic Resonance (2)
Helmholtz Resonator
Actions of a Helmholtz Resonator
Other Acoustic Resonators Tube Resonators
Uniform tube closed at one end
Uniform tube closed at one end (2)
Uniform tube closed at one end
Comparing Helmholtz and tube resonators
Slide 122
Slide 123
Absolute vs relative measurement
bull Relative measures are a ratio of a measure to some reference
bull Relative scales can be referenced to anything you want
bull decibel scale doesnrsquot measure amplitude (intensity or pressure) absolutely but as a ratio of some reference value
Typical reference values
bull Intensityndash 10-12 wattsm2 ndash Threshold for normal hearing at 1000 Hz
bull Complex gt one frequency componentbull Aperiodic Does not repeat itselfbull Frequency components are not systematically
relatedbull May be ndash Continuousndash Transient
Aperiodic sounds Graphic appearance
bull Time domainndash no repeating pattern of pressure change
bull Frequency domainndash the spectrum is dense ndash No ldquopicket fencerdquo
bull Auditory impression sounds lsquonoisyrsquo
Aperiodic sounds Graphic appearance
From Hillenbrand
>
Analysis of complex wavesbull Waves can be summedbull Complex waves are the sum of simple wavesbull Fourier French Mathematician
ndash Any complex waveform may be formed by summing sinusoids of various frequency amplitude and phase
bull Fourier Analysisndash Provides a unique (only one) solution for a given sound signalndash Is reflected in the amplitude and phase spectrum of the signalndash Reveals the building blocks of complex waves which are sinusoids
Learning Objectives
bull Draw and differentiate the waveform and the waveform envelope
bull Draw and differentiate the amplitude spectrum the phase spectrum and the spectrum envelope
bull Differential between short-term spectra and long-term average spectra
The ldquoenveloperdquo of a sound wave
bull Waveform envelopendash imaginary smooth line that follows the peak of the
amplitude of a sound pressure waveformbull Spectrum envelopendash Imaginary smooth line drawn on top of the
amplitude spectrum
Waveform envelope
From Hillenbrand
Waveform envelope
Time
>
Spectrum envelope
Frequency
Ampl
itude
Thought Question
Can an aperiodic and complex periodic sound have identical
spectrum envelopes
Amplitude Spectrum Window Size
bull ldquoshort-termrdquo vs ldquolong-term averagerdquo amplitude spectrum
ldquoInstantaneousrdquo Amplitude Spectra
(Long Term) Average Amplitude Spectrum
Learning Objectivesbull Describe how the amplitude spectrum and the spectrogram are
relatedbull Identify the axis units of the spectrogrambull Provide some advantages of the spectrogram over the
amplitude spectrumbull Distinguish between a wide band and narrow band spectrogram
and outline the different information each providesbull Distinguish between a harmonic and a formant on a
spectrogrambull Be able to draw stylized (highly simplified) spectrograms based
on spectra and spectrum envelopes
The Spectrogram
Rotate90 degrees
F
AF
A
Building a spectrogram
Rotate it so thatThe amplitude isComing out of thepage
F
A This is really narrow because it is a slice in time
F
Time
Building a spectrogram
Dark bands= amplitudePeaks
Time
Freq
uenc
y
Building a spectrogram
Two main types of spectrograms
bull Narrow-band spectrogramsndash Akin to amplitude spectrums ldquolined uprdquondash Frequency resolution is really sharp
bull Wide-band spectrogramsndash Akin to spectrum envelopes ldquolined uprdquondash Frequency resolution not so sharp
Highlights harmonic structure
Highlights spectrum envelope
Wide vs Narrow Band Spectrograms
Learning Objectives
bull Define an acoustic filterbull Draw and label a frequency response curvebull Draw and differentiate different types of acoustic
filtersbull Define terms such as cutoff frequency center
frequency roll off rate gain and bandwidthbull Define and draw a basic filter system and relate that
to the source-filter theory of speech production
What is an ldquoAcousticrdquo Filter
bull holds back (attenuates) certain sounds and lets other sounds through - selective
Why might we be interested in filters
bull Human vocal tract acts like a frequency selective acoustic filter
bull Human auditory system behaves as a frequency selective filter
bull helps us understand how speech is produced and perceived
Kinds of frequency selective filters
Low-pass filtersndash Lets low frequencies ldquopass throughrdquo and attenuates high
frequencies
High-pass filtersndash Lets high frequencies ldquopass throughrdquo and attenuates low
frequencies
Band-pass filtersndash Lets a particular frequency range ldquopass throughrdquo and
attenuates other frequencies
Low Pass Filters
Frequencylow high
Gai
n
+
-
High Pass Filters
Frequencylow high
Gai
n
+
-
Band Pass Filter
Frequencylow high
Gai
n
+
-
Frequency Response Curve (FRC)
Frequencylow high
Gai
n
+
-
Center frequency
lower cutofffrequency
upper cutoff frequency
passband
3 dB
Operation of a filter on a signal
NOTE Amplitude spectrum describes a soundFrequency response curve describes a filter
Learning Objectivesbull Define resonance free and forced vibrationbull Describe how the pendulum and spring mass models can
help explain resonancebull Outline how mass and stiffness influences the resonant
frequency of a mass spring systembull Outline how acoustic resonators behave like acoustic filtersbull Calculate resonant frequencies of a uniform tube based on
its physical dimensionsbull Describe how the wavelength of the sound determines the
resonant frequency of tube
Free vibration
bull objects tend to vibrate at a characteristic or resonant frequency (RF)
Forced vibration
bull A vibrating system can force a nearby system into vibration
bull The efficiency with which this is accomplished is related to the similarity in the resonant frequency (RF) of the two systems
Forced vibration
bull If the RF of the two systems are the same the amplitude of forced vibration will be large
bull If the RF of the two systems are quite different the amplitude of forced vibration will be small or nonexistent
Resonance refers to
bull The tendency for an object to vibrate at a particular frequency or frequencies
bull The ability of a vibrating system to force another system into vibration
Back to the mass spring model
bull Vibratory frequency of the mass spring determined byndash Massndash Stiffness of the spring
httpphetcoloradoeduensimulationmass-spring-lab
Acoustic Resonance
bull Ideas from mechanical resonance also applies to acoustic systems
bull Acoustic chambers will transmit sound frequencies with more or less efficiency depending upon the physical characteristics
bull Therefore they act as filters passing through (and even amplifying) some frequencies and attentuating others
Acoustic Resonance
bull And since they act as filters they have most of the same features of a filter even though we might use different names
bull Center frequency is often termed the resonant frequency
bull Frequency response curve often termed the resonance curve
Helmholtz Resonator
Actions of a Helmholtz Resonator
Stephen M Tasko
Other Acoustic Resonators Tube Resonators
bull Uniform tubes Factors that influence resonancendash Lengthndash Cross-sectional area along its lengthndash Whether it is closed at either or both ends
Uniform tube closed at one end
Uniform tube closed at one end
Stephen M Tasko
Uniform tube closed at one end
First resonance or formant
F1 = c4lWhere
c=speed of sound (35000 cmsec)l = length of the tube
males ~ 175 cmfemales ~ 14 cm
Higher resonantformant frequencies are odd multiples of F1
For examplebull F1 = (c4l )1
bull F2 = (c4l )3
bull F3 = (c4l )5
Comparing Helmholtz and tube resonators
Resonator Features
Sharply tuned Broadly tuned
Resonator Features
An example of the resonance characteristics of the human vocal tract
Frequency
Gain
SPPA 4030 Speech Science
Topic 1 The Speech Chain
The Speech Chain (Denes amp Pinson 1993)
What information is embedded in the speech signal
Branches of science employed to understand speech communication
Physical Quantities Review An Independent Learning Activity
Assignment 1
Topic 2 The Source-Filter Theory of Speech Production An Intr
Producing Speech
Source-Filter Theory of Speech Production
Vocal tract is a tube that can vary its shape
Source Filter Theory
Same Source Different Filter
Different Source Same Filters
Different Source Same Filters (Human)
Different Source Same Filters (Human) (2)
Different Source Same Filters (Human) (3)
Different Source Same Filters (Human) (4)
Different Source Same Filters (Non-Human)
Different Source Same Filters (Non-Human) (2)
Different Source Same Filters (Non-Human) If it quacks like a
Source Filter Theory Applied Alaryngeal Speech
Source-Filter Theory Applied Esophageal Insufflation Test
Source-Filter Theory Applied Tracheoesophageal (TE) Speech
Source Filter Theory Applied The Talkbox
Source-Filter Theory Applied The Talkbox
Topic 3 A Brief Review of Physical Acoustics
Spring Mass Model
What is sound
Sound-conducting media
Model of air molecule vibration (Time 1)
Model of air molecule vibration (Time 2)
Model of air molecule vibration (Time 3)
Model of air molecule vibration (Time 4)
Model of air molecule vibration (Time 5)
Model of air molecule vibration
Wave action of molecular motion
Amplitude waveform
Amplitude waveform (2)
Where is pressure in this model
Pressure waveform
Measuring Sound
Measuring Sound Signal Amplitude
Measuring Sound Signal Amplitude (2)
What units do we use to measure signal amplitude
Brief Review The decibel scale
Absolute vs relative measurement
Typical reference values
Howeverhellip
Linear vs logarithmic
Linear vs logarithmic (2)
Logarithmic Scale
Logarithmic Scale (2)
Combining the idea of logarithmic and relativehellip
Intensity vs Pressure
Extending the formula to pressure
Measuring Sound Frequencyperiod
Measuring Sound Frequencyperiod (2)
Phase Uniform Circular Motion
Initiating a sound waves that differ only in phase
Spatial variation in pressure wave
Spatial variation in pressure wave
Spatial variation in pressure wave (2)
Relation between frequency and wavelength
Learning Objectives
Graphic representation of sound
Same sound different graphs
Classification of sounds
Simple periodic sound
Simple periodic sound Graphic appearance
Complex periodic sounds
Complex periodic sounds Graphic appearance
Complex periodic sounds Graphic appearance (2)
Glottal Source
Amplitude vs Phase Spectrum
Amplitude vs Phase Spectrum (2)
(Complex) Aperiodic sounds
Aperiodic sounds Graphic appearance
Aperiodic sounds Graphic appearance (2)
Analysis of complex waves
Learning Objectives (2)
The ldquoenveloperdquo of a sound wave
Waveform envelope
Waveform envelope (2)
Spectrum envelope
Thought Question
Amplitude Spectrum Window Size
ldquoInstantaneousrdquo Amplitude Spectra
(Long Term) Average Amplitude Spectrum
Slide 90
Learning Objectives (3)
The Spectrogram
Building a spectrogram
Building a spectrogram
Building a spectrogram (2)
Two main types of spectrograms
Wide vs Narrow Band Spectrograms
Learning Objectives (4)
What is an ldquoAcousticrdquo Filter
Why might we be interested in filters
Kinds of frequency selective filters
Low Pass Filters
High Pass Filters
Band Pass Filter
Frequency Response Curve (FRC)
Operation of a filter on a signal
Learning Objectives (5)
Free vibration
Forced vibration
Forced vibration (2)
Resonance refers to
Back to the mass spring model
Acoustic Resonance
Acoustic Resonance (2)
Helmholtz Resonator
Actions of a Helmholtz Resonator
Other Acoustic Resonators Tube Resonators
Uniform tube closed at one end
Uniform tube closed at one end (2)
Uniform tube closed at one end
Comparing Helmholtz and tube resonators
Slide 122
Slide 123
Typical reference values
bull Intensityndash 10-12 wattsm2 ndash Threshold for normal hearing at 1000 Hz
bull Complex gt one frequency componentbull Aperiodic Does not repeat itselfbull Frequency components are not systematically
relatedbull May be ndash Continuousndash Transient
Aperiodic sounds Graphic appearance
bull Time domainndash no repeating pattern of pressure change
bull Frequency domainndash the spectrum is dense ndash No ldquopicket fencerdquo
bull Auditory impression sounds lsquonoisyrsquo
Aperiodic sounds Graphic appearance
From Hillenbrand
>
Analysis of complex wavesbull Waves can be summedbull Complex waves are the sum of simple wavesbull Fourier French Mathematician
ndash Any complex waveform may be formed by summing sinusoids of various frequency amplitude and phase
bull Fourier Analysisndash Provides a unique (only one) solution for a given sound signalndash Is reflected in the amplitude and phase spectrum of the signalndash Reveals the building blocks of complex waves which are sinusoids
Learning Objectives
bull Draw and differentiate the waveform and the waveform envelope
bull Draw and differentiate the amplitude spectrum the phase spectrum and the spectrum envelope
bull Differential between short-term spectra and long-term average spectra
The ldquoenveloperdquo of a sound wave
bull Waveform envelopendash imaginary smooth line that follows the peak of the
amplitude of a sound pressure waveformbull Spectrum envelopendash Imaginary smooth line drawn on top of the
amplitude spectrum
Waveform envelope
From Hillenbrand
Waveform envelope
Time
>
Spectrum envelope
Frequency
Ampl
itude
Thought Question
Can an aperiodic and complex periodic sound have identical
spectrum envelopes
Amplitude Spectrum Window Size
bull ldquoshort-termrdquo vs ldquolong-term averagerdquo amplitude spectrum
ldquoInstantaneousrdquo Amplitude Spectra
(Long Term) Average Amplitude Spectrum
Learning Objectivesbull Describe how the amplitude spectrum and the spectrogram are
relatedbull Identify the axis units of the spectrogrambull Provide some advantages of the spectrogram over the
amplitude spectrumbull Distinguish between a wide band and narrow band spectrogram
and outline the different information each providesbull Distinguish between a harmonic and a formant on a
spectrogrambull Be able to draw stylized (highly simplified) spectrograms based
on spectra and spectrum envelopes
The Spectrogram
Rotate90 degrees
F
AF
A
Building a spectrogram
Rotate it so thatThe amplitude isComing out of thepage
F
A This is really narrow because it is a slice in time
F
Time
Building a spectrogram
Dark bands= amplitudePeaks
Time
Freq
uenc
y
Building a spectrogram
Two main types of spectrograms
bull Narrow-band spectrogramsndash Akin to amplitude spectrums ldquolined uprdquondash Frequency resolution is really sharp
bull Wide-band spectrogramsndash Akin to spectrum envelopes ldquolined uprdquondash Frequency resolution not so sharp
Highlights harmonic structure
Highlights spectrum envelope
Wide vs Narrow Band Spectrograms
Learning Objectives
bull Define an acoustic filterbull Draw and label a frequency response curvebull Draw and differentiate different types of acoustic
filtersbull Define terms such as cutoff frequency center
frequency roll off rate gain and bandwidthbull Define and draw a basic filter system and relate that
to the source-filter theory of speech production
What is an ldquoAcousticrdquo Filter
bull holds back (attenuates) certain sounds and lets other sounds through - selective
Why might we be interested in filters
bull Human vocal tract acts like a frequency selective acoustic filter
bull Human auditory system behaves as a frequency selective filter
bull helps us understand how speech is produced and perceived
Kinds of frequency selective filters
Low-pass filtersndash Lets low frequencies ldquopass throughrdquo and attenuates high
frequencies
High-pass filtersndash Lets high frequencies ldquopass throughrdquo and attenuates low
frequencies
Band-pass filtersndash Lets a particular frequency range ldquopass throughrdquo and
attenuates other frequencies
Low Pass Filters
Frequencylow high
Gai
n
+
-
High Pass Filters
Frequencylow high
Gai
n
+
-
Band Pass Filter
Frequencylow high
Gai
n
+
-
Frequency Response Curve (FRC)
Frequencylow high
Gai
n
+
-
Center frequency
lower cutofffrequency
upper cutoff frequency
passband
3 dB
Operation of a filter on a signal
NOTE Amplitude spectrum describes a soundFrequency response curve describes a filter
Learning Objectivesbull Define resonance free and forced vibrationbull Describe how the pendulum and spring mass models can
help explain resonancebull Outline how mass and stiffness influences the resonant
frequency of a mass spring systembull Outline how acoustic resonators behave like acoustic filtersbull Calculate resonant frequencies of a uniform tube based on
its physical dimensionsbull Describe how the wavelength of the sound determines the
resonant frequency of tube
Free vibration
bull objects tend to vibrate at a characteristic or resonant frequency (RF)
Forced vibration
bull A vibrating system can force a nearby system into vibration
bull The efficiency with which this is accomplished is related to the similarity in the resonant frequency (RF) of the two systems
Forced vibration
bull If the RF of the two systems are the same the amplitude of forced vibration will be large
bull If the RF of the two systems are quite different the amplitude of forced vibration will be small or nonexistent
Resonance refers to
bull The tendency for an object to vibrate at a particular frequency or frequencies
bull The ability of a vibrating system to force another system into vibration
Back to the mass spring model
bull Vibratory frequency of the mass spring determined byndash Massndash Stiffness of the spring
httpphetcoloradoeduensimulationmass-spring-lab
Acoustic Resonance
bull Ideas from mechanical resonance also applies to acoustic systems
bull Acoustic chambers will transmit sound frequencies with more or less efficiency depending upon the physical characteristics
bull Therefore they act as filters passing through (and even amplifying) some frequencies and attentuating others
Acoustic Resonance
bull And since they act as filters they have most of the same features of a filter even though we might use different names
bull Center frequency is often termed the resonant frequency
bull Frequency response curve often termed the resonance curve
Helmholtz Resonator
Actions of a Helmholtz Resonator
Stephen M Tasko
Other Acoustic Resonators Tube Resonators
bull Uniform tubes Factors that influence resonancendash Lengthndash Cross-sectional area along its lengthndash Whether it is closed at either or both ends
Uniform tube closed at one end
Uniform tube closed at one end
Stephen M Tasko
Uniform tube closed at one end
First resonance or formant
F1 = c4lWhere
c=speed of sound (35000 cmsec)l = length of the tube
males ~ 175 cmfemales ~ 14 cm
Higher resonantformant frequencies are odd multiples of F1
For examplebull F1 = (c4l )1
bull F2 = (c4l )3
bull F3 = (c4l )5
Comparing Helmholtz and tube resonators
Resonator Features
Sharply tuned Broadly tuned
Resonator Features
An example of the resonance characteristics of the human vocal tract
Frequency
Gain
SPPA 4030 Speech Science
Topic 1 The Speech Chain
The Speech Chain (Denes amp Pinson 1993)
What information is embedded in the speech signal
Branches of science employed to understand speech communication
Physical Quantities Review An Independent Learning Activity
Assignment 1
Topic 2 The Source-Filter Theory of Speech Production An Intr
Producing Speech
Source-Filter Theory of Speech Production
Vocal tract is a tube that can vary its shape
Source Filter Theory
Same Source Different Filter
Different Source Same Filters
Different Source Same Filters (Human)
Different Source Same Filters (Human) (2)
Different Source Same Filters (Human) (3)
Different Source Same Filters (Human) (4)
Different Source Same Filters (Non-Human)
Different Source Same Filters (Non-Human) (2)
Different Source Same Filters (Non-Human) If it quacks like a
Source Filter Theory Applied Alaryngeal Speech
Source-Filter Theory Applied Esophageal Insufflation Test
Source-Filter Theory Applied Tracheoesophageal (TE) Speech
Source Filter Theory Applied The Talkbox
Source-Filter Theory Applied The Talkbox
Topic 3 A Brief Review of Physical Acoustics
Spring Mass Model
What is sound
Sound-conducting media
Model of air molecule vibration (Time 1)
Model of air molecule vibration (Time 2)
Model of air molecule vibration (Time 3)
Model of air molecule vibration (Time 4)
Model of air molecule vibration (Time 5)
Model of air molecule vibration
Wave action of molecular motion
Amplitude waveform
Amplitude waveform (2)
Where is pressure in this model
Pressure waveform
Measuring Sound
Measuring Sound Signal Amplitude
Measuring Sound Signal Amplitude (2)
What units do we use to measure signal amplitude
Brief Review The decibel scale
Absolute vs relative measurement
Typical reference values
Howeverhellip
Linear vs logarithmic
Linear vs logarithmic (2)
Logarithmic Scale
Logarithmic Scale (2)
Combining the idea of logarithmic and relativehellip
Intensity vs Pressure
Extending the formula to pressure
Measuring Sound Frequencyperiod
Measuring Sound Frequencyperiod (2)
Phase Uniform Circular Motion
Initiating a sound waves that differ only in phase
Spatial variation in pressure wave
Spatial variation in pressure wave
Spatial variation in pressure wave (2)
Relation between frequency and wavelength
Learning Objectives
Graphic representation of sound
Same sound different graphs
Classification of sounds
Simple periodic sound
Simple periodic sound Graphic appearance
Complex periodic sounds
Complex periodic sounds Graphic appearance
Complex periodic sounds Graphic appearance (2)
Glottal Source
Amplitude vs Phase Spectrum
Amplitude vs Phase Spectrum (2)
(Complex) Aperiodic sounds
Aperiodic sounds Graphic appearance
Aperiodic sounds Graphic appearance (2)
Analysis of complex waves
Learning Objectives (2)
The ldquoenveloperdquo of a sound wave
Waveform envelope
Waveform envelope (2)
Spectrum envelope
Thought Question
Amplitude Spectrum Window Size
ldquoInstantaneousrdquo Amplitude Spectra
(Long Term) Average Amplitude Spectrum
Slide 90
Learning Objectives (3)
The Spectrogram
Building a spectrogram
Building a spectrogram
Building a spectrogram (2)
Two main types of spectrograms
Wide vs Narrow Band Spectrograms
Learning Objectives (4)
What is an ldquoAcousticrdquo Filter
Why might we be interested in filters
Kinds of frequency selective filters
Low Pass Filters
High Pass Filters
Band Pass Filter
Frequency Response Curve (FRC)
Operation of a filter on a signal
Learning Objectives (5)
Free vibration
Forced vibration
Forced vibration (2)
Resonance refers to
Back to the mass spring model
Acoustic Resonance
Acoustic Resonance (2)
Helmholtz Resonator
Actions of a Helmholtz Resonator
Other Acoustic Resonators Tube Resonators
Uniform tube closed at one end
Uniform tube closed at one end (2)
Uniform tube closed at one end
Comparing Helmholtz and tube resonators
Slide 122
Slide 123
Howeverhellip
bull You can reference intensitypressure to anything you want
For examplebull Post therapy to pre therapybull Sick people to healthy peoplebull Sound A to sound B
Linear vs logarithmic
bull Linear scale 123hellipbull For example the difference between 2 and
4 is the same as the difference between 8 and 10
bull We say these are additive
Linear vs logarithmic
bull Logarithmic scales are multiplicativebull Recall from high school math and hearing science
10 = 101 = 10 x 1100 = 102 = 10 x 101000= 103 = 10 x 10 x 1001 = 10-1 = 110 x 1
Logarithmic scales use the exponents for the number scalelog1010 = 1log10100 = 2log 101000=3log 1001 = -1
Logarithmic Scale
bull base doesnrsquot have to be 10bull In the natural sciences the base is often 27hellip
or e
Logarithmic Scale
bull Why use such a complicated scalendash logarithmic scale squeezes a very wide range of
magnitudes into a relatively compact scalendash this is roughly how our hearing works in that a
logarithmic scales matches our perception of loudness change
Combining the idea of logarithmic and relativehellip
bull Complex gt one frequency componentbull Aperiodic Does not repeat itselfbull Frequency components are not systematically
relatedbull May be ndash Continuousndash Transient
Aperiodic sounds Graphic appearance
bull Time domainndash no repeating pattern of pressure change
bull Frequency domainndash the spectrum is dense ndash No ldquopicket fencerdquo
bull Auditory impression sounds lsquonoisyrsquo
Aperiodic sounds Graphic appearance
From Hillenbrand
>
Analysis of complex wavesbull Waves can be summedbull Complex waves are the sum of simple wavesbull Fourier French Mathematician
ndash Any complex waveform may be formed by summing sinusoids of various frequency amplitude and phase
bull Fourier Analysisndash Provides a unique (only one) solution for a given sound signalndash Is reflected in the amplitude and phase spectrum of the signalndash Reveals the building blocks of complex waves which are sinusoids
Learning Objectives
bull Draw and differentiate the waveform and the waveform envelope
bull Draw and differentiate the amplitude spectrum the phase spectrum and the spectrum envelope
bull Differential between short-term spectra and long-term average spectra
The ldquoenveloperdquo of a sound wave
bull Waveform envelopendash imaginary smooth line that follows the peak of the
amplitude of a sound pressure waveformbull Spectrum envelopendash Imaginary smooth line drawn on top of the
amplitude spectrum
Waveform envelope
From Hillenbrand
Waveform envelope
Time
>
Spectrum envelope
Frequency
Ampl
itude
Thought Question
Can an aperiodic and complex periodic sound have identical
spectrum envelopes
Amplitude Spectrum Window Size
bull ldquoshort-termrdquo vs ldquolong-term averagerdquo amplitude spectrum
ldquoInstantaneousrdquo Amplitude Spectra
(Long Term) Average Amplitude Spectrum
Learning Objectivesbull Describe how the amplitude spectrum and the spectrogram are
relatedbull Identify the axis units of the spectrogrambull Provide some advantages of the spectrogram over the
amplitude spectrumbull Distinguish between a wide band and narrow band spectrogram
and outline the different information each providesbull Distinguish between a harmonic and a formant on a
spectrogrambull Be able to draw stylized (highly simplified) spectrograms based
on spectra and spectrum envelopes
The Spectrogram
Rotate90 degrees
F
AF
A
Building a spectrogram
Rotate it so thatThe amplitude isComing out of thepage
F
A This is really narrow because it is a slice in time
F
Time
Building a spectrogram
Dark bands= amplitudePeaks
Time
Freq
uenc
y
Building a spectrogram
Two main types of spectrograms
bull Narrow-band spectrogramsndash Akin to amplitude spectrums ldquolined uprdquondash Frequency resolution is really sharp
bull Wide-band spectrogramsndash Akin to spectrum envelopes ldquolined uprdquondash Frequency resolution not so sharp
Highlights harmonic structure
Highlights spectrum envelope
Wide vs Narrow Band Spectrograms
Learning Objectives
bull Define an acoustic filterbull Draw and label a frequency response curvebull Draw and differentiate different types of acoustic
filtersbull Define terms such as cutoff frequency center
frequency roll off rate gain and bandwidthbull Define and draw a basic filter system and relate that
to the source-filter theory of speech production
What is an ldquoAcousticrdquo Filter
bull holds back (attenuates) certain sounds and lets other sounds through - selective
Why might we be interested in filters
bull Human vocal tract acts like a frequency selective acoustic filter
bull Human auditory system behaves as a frequency selective filter
bull helps us understand how speech is produced and perceived
Kinds of frequency selective filters
Low-pass filtersndash Lets low frequencies ldquopass throughrdquo and attenuates high
frequencies
High-pass filtersndash Lets high frequencies ldquopass throughrdquo and attenuates low
frequencies
Band-pass filtersndash Lets a particular frequency range ldquopass throughrdquo and
attenuates other frequencies
Low Pass Filters
Frequencylow high
Gai
n
+
-
High Pass Filters
Frequencylow high
Gai
n
+
-
Band Pass Filter
Frequencylow high
Gai
n
+
-
Frequency Response Curve (FRC)
Frequencylow high
Gai
n
+
-
Center frequency
lower cutofffrequency
upper cutoff frequency
passband
3 dB
Operation of a filter on a signal
NOTE Amplitude spectrum describes a soundFrequency response curve describes a filter
Learning Objectivesbull Define resonance free and forced vibrationbull Describe how the pendulum and spring mass models can
help explain resonancebull Outline how mass and stiffness influences the resonant
frequency of a mass spring systembull Outline how acoustic resonators behave like acoustic filtersbull Calculate resonant frequencies of a uniform tube based on
its physical dimensionsbull Describe how the wavelength of the sound determines the
resonant frequency of tube
Free vibration
bull objects tend to vibrate at a characteristic or resonant frequency (RF)
Forced vibration
bull A vibrating system can force a nearby system into vibration
bull The efficiency with which this is accomplished is related to the similarity in the resonant frequency (RF) of the two systems
Forced vibration
bull If the RF of the two systems are the same the amplitude of forced vibration will be large
bull If the RF of the two systems are quite different the amplitude of forced vibration will be small or nonexistent
Resonance refers to
bull The tendency for an object to vibrate at a particular frequency or frequencies
bull The ability of a vibrating system to force another system into vibration
Back to the mass spring model
bull Vibratory frequency of the mass spring determined byndash Massndash Stiffness of the spring
httpphetcoloradoeduensimulationmass-spring-lab
Acoustic Resonance
bull Ideas from mechanical resonance also applies to acoustic systems
bull Acoustic chambers will transmit sound frequencies with more or less efficiency depending upon the physical characteristics
bull Therefore they act as filters passing through (and even amplifying) some frequencies and attentuating others
Acoustic Resonance
bull And since they act as filters they have most of the same features of a filter even though we might use different names
bull Center frequency is often termed the resonant frequency
bull Frequency response curve often termed the resonance curve
Helmholtz Resonator
Actions of a Helmholtz Resonator
Stephen M Tasko
Other Acoustic Resonators Tube Resonators
bull Uniform tubes Factors that influence resonancendash Lengthndash Cross-sectional area along its lengthndash Whether it is closed at either or both ends
Uniform tube closed at one end
Uniform tube closed at one end
Stephen M Tasko
Uniform tube closed at one end
First resonance or formant
F1 = c4lWhere
c=speed of sound (35000 cmsec)l = length of the tube
males ~ 175 cmfemales ~ 14 cm
Higher resonantformant frequencies are odd multiples of F1
For examplebull F1 = (c4l )1
bull F2 = (c4l )3
bull F3 = (c4l )5
Comparing Helmholtz and tube resonators
Resonator Features
Sharply tuned Broadly tuned
Resonator Features
An example of the resonance characteristics of the human vocal tract
Frequency
Gain
SPPA 4030 Speech Science
Topic 1 The Speech Chain
The Speech Chain (Denes amp Pinson 1993)
What information is embedded in the speech signal
Branches of science employed to understand speech communication
Physical Quantities Review An Independent Learning Activity
Assignment 1
Topic 2 The Source-Filter Theory of Speech Production An Intr
Producing Speech
Source-Filter Theory of Speech Production
Vocal tract is a tube that can vary its shape
Source Filter Theory
Same Source Different Filter
Different Source Same Filters
Different Source Same Filters (Human)
Different Source Same Filters (Human) (2)
Different Source Same Filters (Human) (3)
Different Source Same Filters (Human) (4)
Different Source Same Filters (Non-Human)
Different Source Same Filters (Non-Human) (2)
Different Source Same Filters (Non-Human) If it quacks like a
Source Filter Theory Applied Alaryngeal Speech
Source-Filter Theory Applied Esophageal Insufflation Test
Source-Filter Theory Applied Tracheoesophageal (TE) Speech
Source Filter Theory Applied The Talkbox
Source-Filter Theory Applied The Talkbox
Topic 3 A Brief Review of Physical Acoustics
Spring Mass Model
What is sound
Sound-conducting media
Model of air molecule vibration (Time 1)
Model of air molecule vibration (Time 2)
Model of air molecule vibration (Time 3)
Model of air molecule vibration (Time 4)
Model of air molecule vibration (Time 5)
Model of air molecule vibration
Wave action of molecular motion
Amplitude waveform
Amplitude waveform (2)
Where is pressure in this model
Pressure waveform
Measuring Sound
Measuring Sound Signal Amplitude
Measuring Sound Signal Amplitude (2)
What units do we use to measure signal amplitude
Brief Review The decibel scale
Absolute vs relative measurement
Typical reference values
Howeverhellip
Linear vs logarithmic
Linear vs logarithmic (2)
Logarithmic Scale
Logarithmic Scale (2)
Combining the idea of logarithmic and relativehellip
Intensity vs Pressure
Extending the formula to pressure
Measuring Sound Frequencyperiod
Measuring Sound Frequencyperiod (2)
Phase Uniform Circular Motion
Initiating a sound waves that differ only in phase
Spatial variation in pressure wave
Spatial variation in pressure wave
Spatial variation in pressure wave (2)
Relation between frequency and wavelength
Learning Objectives
Graphic representation of sound
Same sound different graphs
Classification of sounds
Simple periodic sound
Simple periodic sound Graphic appearance
Complex periodic sounds
Complex periodic sounds Graphic appearance
Complex periodic sounds Graphic appearance (2)
Glottal Source
Amplitude vs Phase Spectrum
Amplitude vs Phase Spectrum (2)
(Complex) Aperiodic sounds
Aperiodic sounds Graphic appearance
Aperiodic sounds Graphic appearance (2)
Analysis of complex waves
Learning Objectives (2)
The ldquoenveloperdquo of a sound wave
Waveform envelope
Waveform envelope (2)
Spectrum envelope
Thought Question
Amplitude Spectrum Window Size
ldquoInstantaneousrdquo Amplitude Spectra
(Long Term) Average Amplitude Spectrum
Slide 90
Learning Objectives (3)
The Spectrogram
Building a spectrogram
Building a spectrogram
Building a spectrogram (2)
Two main types of spectrograms
Wide vs Narrow Band Spectrograms
Learning Objectives (4)
What is an ldquoAcousticrdquo Filter
Why might we be interested in filters
Kinds of frequency selective filters
Low Pass Filters
High Pass Filters
Band Pass Filter
Frequency Response Curve (FRC)
Operation of a filter on a signal
Learning Objectives (5)
Free vibration
Forced vibration
Forced vibration (2)
Resonance refers to
Back to the mass spring model
Acoustic Resonance
Acoustic Resonance (2)
Helmholtz Resonator
Actions of a Helmholtz Resonator
Other Acoustic Resonators Tube Resonators
Uniform tube closed at one end
Uniform tube closed at one end (2)
Uniform tube closed at one end
Comparing Helmholtz and tube resonators
Slide 122
Slide 123
Linear vs logarithmic
bull Linear scale 123hellipbull For example the difference between 2 and
4 is the same as the difference between 8 and 10
bull We say these are additive
Linear vs logarithmic
bull Logarithmic scales are multiplicativebull Recall from high school math and hearing science
10 = 101 = 10 x 1100 = 102 = 10 x 101000= 103 = 10 x 10 x 1001 = 10-1 = 110 x 1
Logarithmic scales use the exponents for the number scalelog1010 = 1log10100 = 2log 101000=3log 1001 = -1
Logarithmic Scale
bull base doesnrsquot have to be 10bull In the natural sciences the base is often 27hellip
or e
Logarithmic Scale
bull Why use such a complicated scalendash logarithmic scale squeezes a very wide range of
magnitudes into a relatively compact scalendash this is roughly how our hearing works in that a
logarithmic scales matches our perception of loudness change
Combining the idea of logarithmic and relativehellip
bull Complex gt one frequency componentbull Aperiodic Does not repeat itselfbull Frequency components are not systematically
relatedbull May be ndash Continuousndash Transient
Aperiodic sounds Graphic appearance
bull Time domainndash no repeating pattern of pressure change
bull Frequency domainndash the spectrum is dense ndash No ldquopicket fencerdquo
bull Auditory impression sounds lsquonoisyrsquo
Aperiodic sounds Graphic appearance
From Hillenbrand
>
Analysis of complex wavesbull Waves can be summedbull Complex waves are the sum of simple wavesbull Fourier French Mathematician
ndash Any complex waveform may be formed by summing sinusoids of various frequency amplitude and phase
bull Fourier Analysisndash Provides a unique (only one) solution for a given sound signalndash Is reflected in the amplitude and phase spectrum of the signalndash Reveals the building blocks of complex waves which are sinusoids
Learning Objectives
bull Draw and differentiate the waveform and the waveform envelope
bull Draw and differentiate the amplitude spectrum the phase spectrum and the spectrum envelope
bull Differential between short-term spectra and long-term average spectra
The ldquoenveloperdquo of a sound wave
bull Waveform envelopendash imaginary smooth line that follows the peak of the
amplitude of a sound pressure waveformbull Spectrum envelopendash Imaginary smooth line drawn on top of the
amplitude spectrum
Waveform envelope
From Hillenbrand
Waveform envelope
Time
>
Spectrum envelope
Frequency
Ampl
itude
Thought Question
Can an aperiodic and complex periodic sound have identical
spectrum envelopes
Amplitude Spectrum Window Size
bull ldquoshort-termrdquo vs ldquolong-term averagerdquo amplitude spectrum
ldquoInstantaneousrdquo Amplitude Spectra
(Long Term) Average Amplitude Spectrum
Learning Objectivesbull Describe how the amplitude spectrum and the spectrogram are
relatedbull Identify the axis units of the spectrogrambull Provide some advantages of the spectrogram over the
amplitude spectrumbull Distinguish between a wide band and narrow band spectrogram
and outline the different information each providesbull Distinguish between a harmonic and a formant on a
spectrogrambull Be able to draw stylized (highly simplified) spectrograms based
on spectra and spectrum envelopes
The Spectrogram
Rotate90 degrees
F
AF
A
Building a spectrogram
Rotate it so thatThe amplitude isComing out of thepage
F
A This is really narrow because it is a slice in time
F
Time
Building a spectrogram
Dark bands= amplitudePeaks
Time
Freq
uenc
y
Building a spectrogram
Two main types of spectrograms
bull Narrow-band spectrogramsndash Akin to amplitude spectrums ldquolined uprdquondash Frequency resolution is really sharp
bull Wide-band spectrogramsndash Akin to spectrum envelopes ldquolined uprdquondash Frequency resolution not so sharp
Highlights harmonic structure
Highlights spectrum envelope
Wide vs Narrow Band Spectrograms
Learning Objectives
bull Define an acoustic filterbull Draw and label a frequency response curvebull Draw and differentiate different types of acoustic
filtersbull Define terms such as cutoff frequency center
frequency roll off rate gain and bandwidthbull Define and draw a basic filter system and relate that
to the source-filter theory of speech production
What is an ldquoAcousticrdquo Filter
bull holds back (attenuates) certain sounds and lets other sounds through - selective
Why might we be interested in filters
bull Human vocal tract acts like a frequency selective acoustic filter
bull Human auditory system behaves as a frequency selective filter
bull helps us understand how speech is produced and perceived
Kinds of frequency selective filters
Low-pass filtersndash Lets low frequencies ldquopass throughrdquo and attenuates high
frequencies
High-pass filtersndash Lets high frequencies ldquopass throughrdquo and attenuates low
frequencies
Band-pass filtersndash Lets a particular frequency range ldquopass throughrdquo and
attenuates other frequencies
Low Pass Filters
Frequencylow high
Gai
n
+
-
High Pass Filters
Frequencylow high
Gai
n
+
-
Band Pass Filter
Frequencylow high
Gai
n
+
-
Frequency Response Curve (FRC)
Frequencylow high
Gai
n
+
-
Center frequency
lower cutofffrequency
upper cutoff frequency
passband
3 dB
Operation of a filter on a signal
NOTE Amplitude spectrum describes a soundFrequency response curve describes a filter
Learning Objectivesbull Define resonance free and forced vibrationbull Describe how the pendulum and spring mass models can
help explain resonancebull Outline how mass and stiffness influences the resonant
frequency of a mass spring systembull Outline how acoustic resonators behave like acoustic filtersbull Calculate resonant frequencies of a uniform tube based on
its physical dimensionsbull Describe how the wavelength of the sound determines the
resonant frequency of tube
Free vibration
bull objects tend to vibrate at a characteristic or resonant frequency (RF)
Forced vibration
bull A vibrating system can force a nearby system into vibration
bull The efficiency with which this is accomplished is related to the similarity in the resonant frequency (RF) of the two systems
Forced vibration
bull If the RF of the two systems are the same the amplitude of forced vibration will be large
bull If the RF of the two systems are quite different the amplitude of forced vibration will be small or nonexistent
Resonance refers to
bull The tendency for an object to vibrate at a particular frequency or frequencies
bull The ability of a vibrating system to force another system into vibration
Back to the mass spring model
bull Vibratory frequency of the mass spring determined byndash Massndash Stiffness of the spring
httpphetcoloradoeduensimulationmass-spring-lab
Acoustic Resonance
bull Ideas from mechanical resonance also applies to acoustic systems
bull Acoustic chambers will transmit sound frequencies with more or less efficiency depending upon the physical characteristics
bull Therefore they act as filters passing through (and even amplifying) some frequencies and attentuating others
Acoustic Resonance
bull And since they act as filters they have most of the same features of a filter even though we might use different names
bull Center frequency is often termed the resonant frequency
bull Frequency response curve often termed the resonance curve
Helmholtz Resonator
Actions of a Helmholtz Resonator
Stephen M Tasko
Other Acoustic Resonators Tube Resonators
bull Uniform tubes Factors that influence resonancendash Lengthndash Cross-sectional area along its lengthndash Whether it is closed at either or both ends
Uniform tube closed at one end
Uniform tube closed at one end
Stephen M Tasko
Uniform tube closed at one end
First resonance or formant
F1 = c4lWhere
c=speed of sound (35000 cmsec)l = length of the tube
males ~ 175 cmfemales ~ 14 cm
Higher resonantformant frequencies are odd multiples of F1
For examplebull F1 = (c4l )1
bull F2 = (c4l )3
bull F3 = (c4l )5
Comparing Helmholtz and tube resonators
Resonator Features
Sharply tuned Broadly tuned
Resonator Features
An example of the resonance characteristics of the human vocal tract
Frequency
Gain
SPPA 4030 Speech Science
Topic 1 The Speech Chain
The Speech Chain (Denes amp Pinson 1993)
What information is embedded in the speech signal
Branches of science employed to understand speech communication
Physical Quantities Review An Independent Learning Activity
Assignment 1
Topic 2 The Source-Filter Theory of Speech Production An Intr
Producing Speech
Source-Filter Theory of Speech Production
Vocal tract is a tube that can vary its shape
Source Filter Theory
Same Source Different Filter
Different Source Same Filters
Different Source Same Filters (Human)
Different Source Same Filters (Human) (2)
Different Source Same Filters (Human) (3)
Different Source Same Filters (Human) (4)
Different Source Same Filters (Non-Human)
Different Source Same Filters (Non-Human) (2)
Different Source Same Filters (Non-Human) If it quacks like a
Source Filter Theory Applied Alaryngeal Speech
Source-Filter Theory Applied Esophageal Insufflation Test
Source-Filter Theory Applied Tracheoesophageal (TE) Speech
Source Filter Theory Applied The Talkbox
Source-Filter Theory Applied The Talkbox
Topic 3 A Brief Review of Physical Acoustics
Spring Mass Model
What is sound
Sound-conducting media
Model of air molecule vibration (Time 1)
Model of air molecule vibration (Time 2)
Model of air molecule vibration (Time 3)
Model of air molecule vibration (Time 4)
Model of air molecule vibration (Time 5)
Model of air molecule vibration
Wave action of molecular motion
Amplitude waveform
Amplitude waveform (2)
Where is pressure in this model
Pressure waveform
Measuring Sound
Measuring Sound Signal Amplitude
Measuring Sound Signal Amplitude (2)
What units do we use to measure signal amplitude
Brief Review The decibel scale
Absolute vs relative measurement
Typical reference values
Howeverhellip
Linear vs logarithmic
Linear vs logarithmic (2)
Logarithmic Scale
Logarithmic Scale (2)
Combining the idea of logarithmic and relativehellip
Intensity vs Pressure
Extending the formula to pressure
Measuring Sound Frequencyperiod
Measuring Sound Frequencyperiod (2)
Phase Uniform Circular Motion
Initiating a sound waves that differ only in phase
Spatial variation in pressure wave
Spatial variation in pressure wave
Spatial variation in pressure wave (2)
Relation between frequency and wavelength
Learning Objectives
Graphic representation of sound
Same sound different graphs
Classification of sounds
Simple periodic sound
Simple periodic sound Graphic appearance
Complex periodic sounds
Complex periodic sounds Graphic appearance
Complex periodic sounds Graphic appearance (2)
Glottal Source
Amplitude vs Phase Spectrum
Amplitude vs Phase Spectrum (2)
(Complex) Aperiodic sounds
Aperiodic sounds Graphic appearance
Aperiodic sounds Graphic appearance (2)
Analysis of complex waves
Learning Objectives (2)
The ldquoenveloperdquo of a sound wave
Waveform envelope
Waveform envelope (2)
Spectrum envelope
Thought Question
Amplitude Spectrum Window Size
ldquoInstantaneousrdquo Amplitude Spectra
(Long Term) Average Amplitude Spectrum
Slide 90
Learning Objectives (3)
The Spectrogram
Building a spectrogram
Building a spectrogram
Building a spectrogram (2)
Two main types of spectrograms
Wide vs Narrow Band Spectrograms
Learning Objectives (4)
What is an ldquoAcousticrdquo Filter
Why might we be interested in filters
Kinds of frequency selective filters
Low Pass Filters
High Pass Filters
Band Pass Filter
Frequency Response Curve (FRC)
Operation of a filter on a signal
Learning Objectives (5)
Free vibration
Forced vibration
Forced vibration (2)
Resonance refers to
Back to the mass spring model
Acoustic Resonance
Acoustic Resonance (2)
Helmholtz Resonator
Actions of a Helmholtz Resonator
Other Acoustic Resonators Tube Resonators
Uniform tube closed at one end
Uniform tube closed at one end (2)
Uniform tube closed at one end
Comparing Helmholtz and tube resonators
Slide 122
Slide 123
Linear vs logarithmic
bull Logarithmic scales are multiplicativebull Recall from high school math and hearing science
10 = 101 = 10 x 1100 = 102 = 10 x 101000= 103 = 10 x 10 x 1001 = 10-1 = 110 x 1
Logarithmic scales use the exponents for the number scalelog1010 = 1log10100 = 2log 101000=3log 1001 = -1
Logarithmic Scale
bull base doesnrsquot have to be 10bull In the natural sciences the base is often 27hellip
or e
Logarithmic Scale
bull Why use such a complicated scalendash logarithmic scale squeezes a very wide range of
magnitudes into a relatively compact scalendash this is roughly how our hearing works in that a
logarithmic scales matches our perception of loudness change
Combining the idea of logarithmic and relativehellip
bull Complex gt one frequency componentbull Aperiodic Does not repeat itselfbull Frequency components are not systematically
relatedbull May be ndash Continuousndash Transient
Aperiodic sounds Graphic appearance
bull Time domainndash no repeating pattern of pressure change
bull Frequency domainndash the spectrum is dense ndash No ldquopicket fencerdquo
bull Auditory impression sounds lsquonoisyrsquo
Aperiodic sounds Graphic appearance
From Hillenbrand
>
Analysis of complex wavesbull Waves can be summedbull Complex waves are the sum of simple wavesbull Fourier French Mathematician
ndash Any complex waveform may be formed by summing sinusoids of various frequency amplitude and phase
bull Fourier Analysisndash Provides a unique (only one) solution for a given sound signalndash Is reflected in the amplitude and phase spectrum of the signalndash Reveals the building blocks of complex waves which are sinusoids
Learning Objectives
bull Draw and differentiate the waveform and the waveform envelope
bull Draw and differentiate the amplitude spectrum the phase spectrum and the spectrum envelope
bull Differential between short-term spectra and long-term average spectra
The ldquoenveloperdquo of a sound wave
bull Waveform envelopendash imaginary smooth line that follows the peak of the
amplitude of a sound pressure waveformbull Spectrum envelopendash Imaginary smooth line drawn on top of the
amplitude spectrum
Waveform envelope
From Hillenbrand
Waveform envelope
Time
>
Spectrum envelope
Frequency
Ampl
itude
Thought Question
Can an aperiodic and complex periodic sound have identical
spectrum envelopes
Amplitude Spectrum Window Size
bull ldquoshort-termrdquo vs ldquolong-term averagerdquo amplitude spectrum
ldquoInstantaneousrdquo Amplitude Spectra
(Long Term) Average Amplitude Spectrum
Learning Objectivesbull Describe how the amplitude spectrum and the spectrogram are
relatedbull Identify the axis units of the spectrogrambull Provide some advantages of the spectrogram over the
amplitude spectrumbull Distinguish between a wide band and narrow band spectrogram
and outline the different information each providesbull Distinguish between a harmonic and a formant on a
spectrogrambull Be able to draw stylized (highly simplified) spectrograms based
on spectra and spectrum envelopes
The Spectrogram
Rotate90 degrees
F
AF
A
Building a spectrogram
Rotate it so thatThe amplitude isComing out of thepage
F
A This is really narrow because it is a slice in time
F
Time
Building a spectrogram
Dark bands= amplitudePeaks
Time
Freq
uenc
y
Building a spectrogram
Two main types of spectrograms
bull Narrow-band spectrogramsndash Akin to amplitude spectrums ldquolined uprdquondash Frequency resolution is really sharp
bull Wide-band spectrogramsndash Akin to spectrum envelopes ldquolined uprdquondash Frequency resolution not so sharp
Highlights harmonic structure
Highlights spectrum envelope
Wide vs Narrow Band Spectrograms
Learning Objectives
bull Define an acoustic filterbull Draw and label a frequency response curvebull Draw and differentiate different types of acoustic
filtersbull Define terms such as cutoff frequency center
frequency roll off rate gain and bandwidthbull Define and draw a basic filter system and relate that
to the source-filter theory of speech production
What is an ldquoAcousticrdquo Filter
bull holds back (attenuates) certain sounds and lets other sounds through - selective
Why might we be interested in filters
bull Human vocal tract acts like a frequency selective acoustic filter
bull Human auditory system behaves as a frequency selective filter
bull helps us understand how speech is produced and perceived
Kinds of frequency selective filters
Low-pass filtersndash Lets low frequencies ldquopass throughrdquo and attenuates high
frequencies
High-pass filtersndash Lets high frequencies ldquopass throughrdquo and attenuates low
frequencies
Band-pass filtersndash Lets a particular frequency range ldquopass throughrdquo and
attenuates other frequencies
Low Pass Filters
Frequencylow high
Gai
n
+
-
High Pass Filters
Frequencylow high
Gai
n
+
-
Band Pass Filter
Frequencylow high
Gai
n
+
-
Frequency Response Curve (FRC)
Frequencylow high
Gai
n
+
-
Center frequency
lower cutofffrequency
upper cutoff frequency
passband
3 dB
Operation of a filter on a signal
NOTE Amplitude spectrum describes a soundFrequency response curve describes a filter
Learning Objectivesbull Define resonance free and forced vibrationbull Describe how the pendulum and spring mass models can
help explain resonancebull Outline how mass and stiffness influences the resonant
frequency of a mass spring systembull Outline how acoustic resonators behave like acoustic filtersbull Calculate resonant frequencies of a uniform tube based on
its physical dimensionsbull Describe how the wavelength of the sound determines the
resonant frequency of tube
Free vibration
bull objects tend to vibrate at a characteristic or resonant frequency (RF)
Forced vibration
bull A vibrating system can force a nearby system into vibration
bull The efficiency with which this is accomplished is related to the similarity in the resonant frequency (RF) of the two systems
Forced vibration
bull If the RF of the two systems are the same the amplitude of forced vibration will be large
bull If the RF of the two systems are quite different the amplitude of forced vibration will be small or nonexistent
Resonance refers to
bull The tendency for an object to vibrate at a particular frequency or frequencies
bull The ability of a vibrating system to force another system into vibration
Back to the mass spring model
bull Vibratory frequency of the mass spring determined byndash Massndash Stiffness of the spring
httpphetcoloradoeduensimulationmass-spring-lab
Acoustic Resonance
bull Ideas from mechanical resonance also applies to acoustic systems
bull Acoustic chambers will transmit sound frequencies with more or less efficiency depending upon the physical characteristics
bull Therefore they act as filters passing through (and even amplifying) some frequencies and attentuating others
Acoustic Resonance
bull And since they act as filters they have most of the same features of a filter even though we might use different names
bull Center frequency is often termed the resonant frequency
bull Frequency response curve often termed the resonance curve
Helmholtz Resonator
Actions of a Helmholtz Resonator
Stephen M Tasko
Other Acoustic Resonators Tube Resonators
bull Uniform tubes Factors that influence resonancendash Lengthndash Cross-sectional area along its lengthndash Whether it is closed at either or both ends
Uniform tube closed at one end
Uniform tube closed at one end
Stephen M Tasko
Uniform tube closed at one end
First resonance or formant
F1 = c4lWhere
c=speed of sound (35000 cmsec)l = length of the tube
males ~ 175 cmfemales ~ 14 cm
Higher resonantformant frequencies are odd multiples of F1
For examplebull F1 = (c4l )1
bull F2 = (c4l )3
bull F3 = (c4l )5
Comparing Helmholtz and tube resonators
Resonator Features
Sharply tuned Broadly tuned
Resonator Features
An example of the resonance characteristics of the human vocal tract
Frequency
Gain
SPPA 4030 Speech Science
Topic 1 The Speech Chain
The Speech Chain (Denes amp Pinson 1993)
What information is embedded in the speech signal
Branches of science employed to understand speech communication
Physical Quantities Review An Independent Learning Activity
Assignment 1
Topic 2 The Source-Filter Theory of Speech Production An Intr
Producing Speech
Source-Filter Theory of Speech Production
Vocal tract is a tube that can vary its shape
Source Filter Theory
Same Source Different Filter
Different Source Same Filters
Different Source Same Filters (Human)
Different Source Same Filters (Human) (2)
Different Source Same Filters (Human) (3)
Different Source Same Filters (Human) (4)
Different Source Same Filters (Non-Human)
Different Source Same Filters (Non-Human) (2)
Different Source Same Filters (Non-Human) If it quacks like a
Source Filter Theory Applied Alaryngeal Speech
Source-Filter Theory Applied Esophageal Insufflation Test
Source-Filter Theory Applied Tracheoesophageal (TE) Speech
Source Filter Theory Applied The Talkbox
Source-Filter Theory Applied The Talkbox
Topic 3 A Brief Review of Physical Acoustics
Spring Mass Model
What is sound
Sound-conducting media
Model of air molecule vibration (Time 1)
Model of air molecule vibration (Time 2)
Model of air molecule vibration (Time 3)
Model of air molecule vibration (Time 4)
Model of air molecule vibration (Time 5)
Model of air molecule vibration
Wave action of molecular motion
Amplitude waveform
Amplitude waveform (2)
Where is pressure in this model
Pressure waveform
Measuring Sound
Measuring Sound Signal Amplitude
Measuring Sound Signal Amplitude (2)
What units do we use to measure signal amplitude
Brief Review The decibel scale
Absolute vs relative measurement
Typical reference values
Howeverhellip
Linear vs logarithmic
Linear vs logarithmic (2)
Logarithmic Scale
Logarithmic Scale (2)
Combining the idea of logarithmic and relativehellip
Intensity vs Pressure
Extending the formula to pressure
Measuring Sound Frequencyperiod
Measuring Sound Frequencyperiod (2)
Phase Uniform Circular Motion
Initiating a sound waves that differ only in phase
Spatial variation in pressure wave
Spatial variation in pressure wave
Spatial variation in pressure wave (2)
Relation between frequency and wavelength
Learning Objectives
Graphic representation of sound
Same sound different graphs
Classification of sounds
Simple periodic sound
Simple periodic sound Graphic appearance
Complex periodic sounds
Complex periodic sounds Graphic appearance
Complex periodic sounds Graphic appearance (2)
Glottal Source
Amplitude vs Phase Spectrum
Amplitude vs Phase Spectrum (2)
(Complex) Aperiodic sounds
Aperiodic sounds Graphic appearance
Aperiodic sounds Graphic appearance (2)
Analysis of complex waves
Learning Objectives (2)
The ldquoenveloperdquo of a sound wave
Waveform envelope
Waveform envelope (2)
Spectrum envelope
Thought Question
Amplitude Spectrum Window Size
ldquoInstantaneousrdquo Amplitude Spectra
(Long Term) Average Amplitude Spectrum
Slide 90
Learning Objectives (3)
The Spectrogram
Building a spectrogram
Building a spectrogram
Building a spectrogram (2)
Two main types of spectrograms
Wide vs Narrow Band Spectrograms
Learning Objectives (4)
What is an ldquoAcousticrdquo Filter
Why might we be interested in filters
Kinds of frequency selective filters
Low Pass Filters
High Pass Filters
Band Pass Filter
Frequency Response Curve (FRC)
Operation of a filter on a signal
Learning Objectives (5)
Free vibration
Forced vibration
Forced vibration (2)
Resonance refers to
Back to the mass spring model
Acoustic Resonance
Acoustic Resonance (2)
Helmholtz Resonator
Actions of a Helmholtz Resonator
Other Acoustic Resonators Tube Resonators
Uniform tube closed at one end
Uniform tube closed at one end (2)
Uniform tube closed at one end
Comparing Helmholtz and tube resonators
Slide 122
Slide 123
Logarithmic Scale
bull base doesnrsquot have to be 10bull In the natural sciences the base is often 27hellip
or e
Logarithmic Scale
bull Why use such a complicated scalendash logarithmic scale squeezes a very wide range of
magnitudes into a relatively compact scalendash this is roughly how our hearing works in that a
logarithmic scales matches our perception of loudness change
Combining the idea of logarithmic and relativehellip
bull Complex gt one frequency componentbull Aperiodic Does not repeat itselfbull Frequency components are not systematically
relatedbull May be ndash Continuousndash Transient
Aperiodic sounds Graphic appearance
bull Time domainndash no repeating pattern of pressure change
bull Frequency domainndash the spectrum is dense ndash No ldquopicket fencerdquo
bull Auditory impression sounds lsquonoisyrsquo
Aperiodic sounds Graphic appearance
From Hillenbrand
>
Analysis of complex wavesbull Waves can be summedbull Complex waves are the sum of simple wavesbull Fourier French Mathematician
ndash Any complex waveform may be formed by summing sinusoids of various frequency amplitude and phase
bull Fourier Analysisndash Provides a unique (only one) solution for a given sound signalndash Is reflected in the amplitude and phase spectrum of the signalndash Reveals the building blocks of complex waves which are sinusoids
Learning Objectives
bull Draw and differentiate the waveform and the waveform envelope
bull Draw and differentiate the amplitude spectrum the phase spectrum and the spectrum envelope
bull Differential between short-term spectra and long-term average spectra
The ldquoenveloperdquo of a sound wave
bull Waveform envelopendash imaginary smooth line that follows the peak of the
amplitude of a sound pressure waveformbull Spectrum envelopendash Imaginary smooth line drawn on top of the
amplitude spectrum
Waveform envelope
From Hillenbrand
Waveform envelope
Time
>
Spectrum envelope
Frequency
Ampl
itude
Thought Question
Can an aperiodic and complex periodic sound have identical
spectrum envelopes
Amplitude Spectrum Window Size
bull ldquoshort-termrdquo vs ldquolong-term averagerdquo amplitude spectrum
ldquoInstantaneousrdquo Amplitude Spectra
(Long Term) Average Amplitude Spectrum
Learning Objectivesbull Describe how the amplitude spectrum and the spectrogram are
relatedbull Identify the axis units of the spectrogrambull Provide some advantages of the spectrogram over the
amplitude spectrumbull Distinguish between a wide band and narrow band spectrogram
and outline the different information each providesbull Distinguish between a harmonic and a formant on a
spectrogrambull Be able to draw stylized (highly simplified) spectrograms based
on spectra and spectrum envelopes
The Spectrogram
Rotate90 degrees
F
AF
A
Building a spectrogram
Rotate it so thatThe amplitude isComing out of thepage
F
A This is really narrow because it is a slice in time
F
Time
Building a spectrogram
Dark bands= amplitudePeaks
Time
Freq
uenc
y
Building a spectrogram
Two main types of spectrograms
bull Narrow-band spectrogramsndash Akin to amplitude spectrums ldquolined uprdquondash Frequency resolution is really sharp
bull Wide-band spectrogramsndash Akin to spectrum envelopes ldquolined uprdquondash Frequency resolution not so sharp
Highlights harmonic structure
Highlights spectrum envelope
Wide vs Narrow Band Spectrograms
Learning Objectives
bull Define an acoustic filterbull Draw and label a frequency response curvebull Draw and differentiate different types of acoustic
filtersbull Define terms such as cutoff frequency center
frequency roll off rate gain and bandwidthbull Define and draw a basic filter system and relate that
to the source-filter theory of speech production
What is an ldquoAcousticrdquo Filter
bull holds back (attenuates) certain sounds and lets other sounds through - selective
Why might we be interested in filters
bull Human vocal tract acts like a frequency selective acoustic filter
bull Human auditory system behaves as a frequency selective filter
bull helps us understand how speech is produced and perceived
Kinds of frequency selective filters
Low-pass filtersndash Lets low frequencies ldquopass throughrdquo and attenuates high
frequencies
High-pass filtersndash Lets high frequencies ldquopass throughrdquo and attenuates low
frequencies
Band-pass filtersndash Lets a particular frequency range ldquopass throughrdquo and
attenuates other frequencies
Low Pass Filters
Frequencylow high
Gai
n
+
-
High Pass Filters
Frequencylow high
Gai
n
+
-
Band Pass Filter
Frequencylow high
Gai
n
+
-
Frequency Response Curve (FRC)
Frequencylow high
Gai
n
+
-
Center frequency
lower cutofffrequency
upper cutoff frequency
passband
3 dB
Operation of a filter on a signal
NOTE Amplitude spectrum describes a soundFrequency response curve describes a filter
Learning Objectivesbull Define resonance free and forced vibrationbull Describe how the pendulum and spring mass models can
help explain resonancebull Outline how mass and stiffness influences the resonant
frequency of a mass spring systembull Outline how acoustic resonators behave like acoustic filtersbull Calculate resonant frequencies of a uniform tube based on
its physical dimensionsbull Describe how the wavelength of the sound determines the
resonant frequency of tube
Free vibration
bull objects tend to vibrate at a characteristic or resonant frequency (RF)
Forced vibration
bull A vibrating system can force a nearby system into vibration
bull The efficiency with which this is accomplished is related to the similarity in the resonant frequency (RF) of the two systems
Forced vibration
bull If the RF of the two systems are the same the amplitude of forced vibration will be large
bull If the RF of the two systems are quite different the amplitude of forced vibration will be small or nonexistent
Resonance refers to
bull The tendency for an object to vibrate at a particular frequency or frequencies
bull The ability of a vibrating system to force another system into vibration
Back to the mass spring model
bull Vibratory frequency of the mass spring determined byndash Massndash Stiffness of the spring
httpphetcoloradoeduensimulationmass-spring-lab
Acoustic Resonance
bull Ideas from mechanical resonance also applies to acoustic systems
bull Acoustic chambers will transmit sound frequencies with more or less efficiency depending upon the physical characteristics
bull Therefore they act as filters passing through (and even amplifying) some frequencies and attentuating others
Acoustic Resonance
bull And since they act as filters they have most of the same features of a filter even though we might use different names
bull Center frequency is often termed the resonant frequency
bull Frequency response curve often termed the resonance curve
Helmholtz Resonator
Actions of a Helmholtz Resonator
Stephen M Tasko
Other Acoustic Resonators Tube Resonators
bull Uniform tubes Factors that influence resonancendash Lengthndash Cross-sectional area along its lengthndash Whether it is closed at either or both ends
Uniform tube closed at one end
Uniform tube closed at one end
Stephen M Tasko
Uniform tube closed at one end
First resonance or formant
F1 = c4lWhere
c=speed of sound (35000 cmsec)l = length of the tube
males ~ 175 cmfemales ~ 14 cm
Higher resonantformant frequencies are odd multiples of F1
For examplebull F1 = (c4l )1
bull F2 = (c4l )3
bull F3 = (c4l )5
Comparing Helmholtz and tube resonators
Resonator Features
Sharply tuned Broadly tuned
Resonator Features
An example of the resonance characteristics of the human vocal tract
Frequency
Gain
SPPA 4030 Speech Science
Topic 1 The Speech Chain
The Speech Chain (Denes amp Pinson 1993)
What information is embedded in the speech signal
Branches of science employed to understand speech communication
Physical Quantities Review An Independent Learning Activity
Assignment 1
Topic 2 The Source-Filter Theory of Speech Production An Intr
Producing Speech
Source-Filter Theory of Speech Production
Vocal tract is a tube that can vary its shape
Source Filter Theory
Same Source Different Filter
Different Source Same Filters
Different Source Same Filters (Human)
Different Source Same Filters (Human) (2)
Different Source Same Filters (Human) (3)
Different Source Same Filters (Human) (4)
Different Source Same Filters (Non-Human)
Different Source Same Filters (Non-Human) (2)
Different Source Same Filters (Non-Human) If it quacks like a
Source Filter Theory Applied Alaryngeal Speech
Source-Filter Theory Applied Esophageal Insufflation Test
Source-Filter Theory Applied Tracheoesophageal (TE) Speech
Source Filter Theory Applied The Talkbox
Source-Filter Theory Applied The Talkbox
Topic 3 A Brief Review of Physical Acoustics
Spring Mass Model
What is sound
Sound-conducting media
Model of air molecule vibration (Time 1)
Model of air molecule vibration (Time 2)
Model of air molecule vibration (Time 3)
Model of air molecule vibration (Time 4)
Model of air molecule vibration (Time 5)
Model of air molecule vibration
Wave action of molecular motion
Amplitude waveform
Amplitude waveform (2)
Where is pressure in this model
Pressure waveform
Measuring Sound
Measuring Sound Signal Amplitude
Measuring Sound Signal Amplitude (2)
What units do we use to measure signal amplitude
Brief Review The decibel scale
Absolute vs relative measurement
Typical reference values
Howeverhellip
Linear vs logarithmic
Linear vs logarithmic (2)
Logarithmic Scale
Logarithmic Scale (2)
Combining the idea of logarithmic and relativehellip
Intensity vs Pressure
Extending the formula to pressure
Measuring Sound Frequencyperiod
Measuring Sound Frequencyperiod (2)
Phase Uniform Circular Motion
Initiating a sound waves that differ only in phase
Spatial variation in pressure wave
Spatial variation in pressure wave
Spatial variation in pressure wave (2)
Relation between frequency and wavelength
Learning Objectives
Graphic representation of sound
Same sound different graphs
Classification of sounds
Simple periodic sound
Simple periodic sound Graphic appearance
Complex periodic sounds
Complex periodic sounds Graphic appearance
Complex periodic sounds Graphic appearance (2)
Glottal Source
Amplitude vs Phase Spectrum
Amplitude vs Phase Spectrum (2)
(Complex) Aperiodic sounds
Aperiodic sounds Graphic appearance
Aperiodic sounds Graphic appearance (2)
Analysis of complex waves
Learning Objectives (2)
The ldquoenveloperdquo of a sound wave
Waveform envelope
Waveform envelope (2)
Spectrum envelope
Thought Question
Amplitude Spectrum Window Size
ldquoInstantaneousrdquo Amplitude Spectra
(Long Term) Average Amplitude Spectrum
Slide 90
Learning Objectives (3)
The Spectrogram
Building a spectrogram
Building a spectrogram
Building a spectrogram (2)
Two main types of spectrograms
Wide vs Narrow Band Spectrograms
Learning Objectives (4)
What is an ldquoAcousticrdquo Filter
Why might we be interested in filters
Kinds of frequency selective filters
Low Pass Filters
High Pass Filters
Band Pass Filter
Frequency Response Curve (FRC)
Operation of a filter on a signal
Learning Objectives (5)
Free vibration
Forced vibration
Forced vibration (2)
Resonance refers to
Back to the mass spring model
Acoustic Resonance
Acoustic Resonance (2)
Helmholtz Resonator
Actions of a Helmholtz Resonator
Other Acoustic Resonators Tube Resonators
Uniform tube closed at one end
Uniform tube closed at one end (2)
Uniform tube closed at one end
Comparing Helmholtz and tube resonators
Slide 122
Slide 123
Logarithmic Scale
bull Why use such a complicated scalendash logarithmic scale squeezes a very wide range of
magnitudes into a relatively compact scalendash this is roughly how our hearing works in that a
logarithmic scales matches our perception of loudness change
Combining the idea of logarithmic and relativehellip
bull Complex gt one frequency componentbull Aperiodic Does not repeat itselfbull Frequency components are not systematically
relatedbull May be ndash Continuousndash Transient
Aperiodic sounds Graphic appearance
bull Time domainndash no repeating pattern of pressure change
bull Frequency domainndash the spectrum is dense ndash No ldquopicket fencerdquo
bull Auditory impression sounds lsquonoisyrsquo
Aperiodic sounds Graphic appearance
From Hillenbrand
>
Analysis of complex wavesbull Waves can be summedbull Complex waves are the sum of simple wavesbull Fourier French Mathematician
ndash Any complex waveform may be formed by summing sinusoids of various frequency amplitude and phase
bull Fourier Analysisndash Provides a unique (only one) solution for a given sound signalndash Is reflected in the amplitude and phase spectrum of the signalndash Reveals the building blocks of complex waves which are sinusoids
Learning Objectives
bull Draw and differentiate the waveform and the waveform envelope
bull Draw and differentiate the amplitude spectrum the phase spectrum and the spectrum envelope
bull Differential between short-term spectra and long-term average spectra
The ldquoenveloperdquo of a sound wave
bull Waveform envelopendash imaginary smooth line that follows the peak of the
amplitude of a sound pressure waveformbull Spectrum envelopendash Imaginary smooth line drawn on top of the
amplitude spectrum
Waveform envelope
From Hillenbrand
Waveform envelope
Time
>
Spectrum envelope
Frequency
Ampl
itude
Thought Question
Can an aperiodic and complex periodic sound have identical
spectrum envelopes
Amplitude Spectrum Window Size
bull ldquoshort-termrdquo vs ldquolong-term averagerdquo amplitude spectrum
ldquoInstantaneousrdquo Amplitude Spectra
(Long Term) Average Amplitude Spectrum
Learning Objectivesbull Describe how the amplitude spectrum and the spectrogram are
relatedbull Identify the axis units of the spectrogrambull Provide some advantages of the spectrogram over the
amplitude spectrumbull Distinguish between a wide band and narrow band spectrogram
and outline the different information each providesbull Distinguish between a harmonic and a formant on a
spectrogrambull Be able to draw stylized (highly simplified) spectrograms based
on spectra and spectrum envelopes
The Spectrogram
Rotate90 degrees
F
AF
A
Building a spectrogram
Rotate it so thatThe amplitude isComing out of thepage
F
A This is really narrow because it is a slice in time
F
Time
Building a spectrogram
Dark bands= amplitudePeaks
Time
Freq
uenc
y
Building a spectrogram
Two main types of spectrograms
bull Narrow-band spectrogramsndash Akin to amplitude spectrums ldquolined uprdquondash Frequency resolution is really sharp
bull Wide-band spectrogramsndash Akin to spectrum envelopes ldquolined uprdquondash Frequency resolution not so sharp
Highlights harmonic structure
Highlights spectrum envelope
Wide vs Narrow Band Spectrograms
Learning Objectives
bull Define an acoustic filterbull Draw and label a frequency response curvebull Draw and differentiate different types of acoustic
filtersbull Define terms such as cutoff frequency center
frequency roll off rate gain and bandwidthbull Define and draw a basic filter system and relate that
to the source-filter theory of speech production
What is an ldquoAcousticrdquo Filter
bull holds back (attenuates) certain sounds and lets other sounds through - selective
Why might we be interested in filters
bull Human vocal tract acts like a frequency selective acoustic filter
bull Human auditory system behaves as a frequency selective filter
bull helps us understand how speech is produced and perceived
Kinds of frequency selective filters
Low-pass filtersndash Lets low frequencies ldquopass throughrdquo and attenuates high
frequencies
High-pass filtersndash Lets high frequencies ldquopass throughrdquo and attenuates low
frequencies
Band-pass filtersndash Lets a particular frequency range ldquopass throughrdquo and
attenuates other frequencies
Low Pass Filters
Frequencylow high
Gai
n
+
-
High Pass Filters
Frequencylow high
Gai
n
+
-
Band Pass Filter
Frequencylow high
Gai
n
+
-
Frequency Response Curve (FRC)
Frequencylow high
Gai
n
+
-
Center frequency
lower cutofffrequency
upper cutoff frequency
passband
3 dB
Operation of a filter on a signal
NOTE Amplitude spectrum describes a soundFrequency response curve describes a filter
Learning Objectivesbull Define resonance free and forced vibrationbull Describe how the pendulum and spring mass models can
help explain resonancebull Outline how mass and stiffness influences the resonant
frequency of a mass spring systembull Outline how acoustic resonators behave like acoustic filtersbull Calculate resonant frequencies of a uniform tube based on
its physical dimensionsbull Describe how the wavelength of the sound determines the
resonant frequency of tube
Free vibration
bull objects tend to vibrate at a characteristic or resonant frequency (RF)
Forced vibration
bull A vibrating system can force a nearby system into vibration
bull The efficiency with which this is accomplished is related to the similarity in the resonant frequency (RF) of the two systems
Forced vibration
bull If the RF of the two systems are the same the amplitude of forced vibration will be large
bull If the RF of the two systems are quite different the amplitude of forced vibration will be small or nonexistent
Resonance refers to
bull The tendency for an object to vibrate at a particular frequency or frequencies
bull The ability of a vibrating system to force another system into vibration
Back to the mass spring model
bull Vibratory frequency of the mass spring determined byndash Massndash Stiffness of the spring
httpphetcoloradoeduensimulationmass-spring-lab
Acoustic Resonance
bull Ideas from mechanical resonance also applies to acoustic systems
bull Acoustic chambers will transmit sound frequencies with more or less efficiency depending upon the physical characteristics
bull Therefore they act as filters passing through (and even amplifying) some frequencies and attentuating others
Acoustic Resonance
bull And since they act as filters they have most of the same features of a filter even though we might use different names
bull Center frequency is often termed the resonant frequency
bull Frequency response curve often termed the resonance curve
Helmholtz Resonator
Actions of a Helmholtz Resonator
Stephen M Tasko
Other Acoustic Resonators Tube Resonators
bull Uniform tubes Factors that influence resonancendash Lengthndash Cross-sectional area along its lengthndash Whether it is closed at either or both ends
Uniform tube closed at one end
Uniform tube closed at one end
Stephen M Tasko
Uniform tube closed at one end
First resonance or formant
F1 = c4lWhere
c=speed of sound (35000 cmsec)l = length of the tube
males ~ 175 cmfemales ~ 14 cm
Higher resonantformant frequencies are odd multiples of F1
For examplebull F1 = (c4l )1
bull F2 = (c4l )3
bull F3 = (c4l )5
Comparing Helmholtz and tube resonators
Resonator Features
Sharply tuned Broadly tuned
Resonator Features
An example of the resonance characteristics of the human vocal tract
Frequency
Gain
SPPA 4030 Speech Science
Topic 1 The Speech Chain
The Speech Chain (Denes amp Pinson 1993)
What information is embedded in the speech signal
Branches of science employed to understand speech communication
Physical Quantities Review An Independent Learning Activity
Assignment 1
Topic 2 The Source-Filter Theory of Speech Production An Intr
Producing Speech
Source-Filter Theory of Speech Production
Vocal tract is a tube that can vary its shape
Source Filter Theory
Same Source Different Filter
Different Source Same Filters
Different Source Same Filters (Human)
Different Source Same Filters (Human) (2)
Different Source Same Filters (Human) (3)
Different Source Same Filters (Human) (4)
Different Source Same Filters (Non-Human)
Different Source Same Filters (Non-Human) (2)
Different Source Same Filters (Non-Human) If it quacks like a
Source Filter Theory Applied Alaryngeal Speech
Source-Filter Theory Applied Esophageal Insufflation Test
Source-Filter Theory Applied Tracheoesophageal (TE) Speech
Source Filter Theory Applied The Talkbox
Source-Filter Theory Applied The Talkbox
Topic 3 A Brief Review of Physical Acoustics
Spring Mass Model
What is sound
Sound-conducting media
Model of air molecule vibration (Time 1)
Model of air molecule vibration (Time 2)
Model of air molecule vibration (Time 3)
Model of air molecule vibration (Time 4)
Model of air molecule vibration (Time 5)
Model of air molecule vibration
Wave action of molecular motion
Amplitude waveform
Amplitude waveform (2)
Where is pressure in this model
Pressure waveform
Measuring Sound
Measuring Sound Signal Amplitude
Measuring Sound Signal Amplitude (2)
What units do we use to measure signal amplitude
Brief Review The decibel scale
Absolute vs relative measurement
Typical reference values
Howeverhellip
Linear vs logarithmic
Linear vs logarithmic (2)
Logarithmic Scale
Logarithmic Scale (2)
Combining the idea of logarithmic and relativehellip
Intensity vs Pressure
Extending the formula to pressure
Measuring Sound Frequencyperiod
Measuring Sound Frequencyperiod (2)
Phase Uniform Circular Motion
Initiating a sound waves that differ only in phase
Spatial variation in pressure wave
Spatial variation in pressure wave
Spatial variation in pressure wave (2)
Relation between frequency and wavelength
Learning Objectives
Graphic representation of sound
Same sound different graphs
Classification of sounds
Simple periodic sound
Simple periodic sound Graphic appearance
Complex periodic sounds
Complex periodic sounds Graphic appearance
Complex periodic sounds Graphic appearance (2)
Glottal Source
Amplitude vs Phase Spectrum
Amplitude vs Phase Spectrum (2)
(Complex) Aperiodic sounds
Aperiodic sounds Graphic appearance
Aperiodic sounds Graphic appearance (2)
Analysis of complex waves
Learning Objectives (2)
The ldquoenveloperdquo of a sound wave
Waveform envelope
Waveform envelope (2)
Spectrum envelope
Thought Question
Amplitude Spectrum Window Size
ldquoInstantaneousrdquo Amplitude Spectra
(Long Term) Average Amplitude Spectrum
Slide 90
Learning Objectives (3)
The Spectrogram
Building a spectrogram
Building a spectrogram
Building a spectrogram (2)
Two main types of spectrograms
Wide vs Narrow Band Spectrograms
Learning Objectives (4)
What is an ldquoAcousticrdquo Filter
Why might we be interested in filters
Kinds of frequency selective filters
Low Pass Filters
High Pass Filters
Band Pass Filter
Frequency Response Curve (FRC)
Operation of a filter on a signal
Learning Objectives (5)
Free vibration
Forced vibration
Forced vibration (2)
Resonance refers to
Back to the mass spring model
Acoustic Resonance
Acoustic Resonance (2)
Helmholtz Resonator
Actions of a Helmholtz Resonator
Other Acoustic Resonators Tube Resonators
Uniform tube closed at one end
Uniform tube closed at one end (2)
Uniform tube closed at one end
Comparing Helmholtz and tube resonators
Slide 122
Slide 123
Combining the idea of logarithmic and relativehellip
bull Complex gt one frequency componentbull Aperiodic Does not repeat itselfbull Frequency components are not systematically
relatedbull May be ndash Continuousndash Transient
Aperiodic sounds Graphic appearance
bull Time domainndash no repeating pattern of pressure change
bull Frequency domainndash the spectrum is dense ndash No ldquopicket fencerdquo
bull Auditory impression sounds lsquonoisyrsquo
Aperiodic sounds Graphic appearance
From Hillenbrand
>
Analysis of complex wavesbull Waves can be summedbull Complex waves are the sum of simple wavesbull Fourier French Mathematician
ndash Any complex waveform may be formed by summing sinusoids of various frequency amplitude and phase
bull Fourier Analysisndash Provides a unique (only one) solution for a given sound signalndash Is reflected in the amplitude and phase spectrum of the signalndash Reveals the building blocks of complex waves which are sinusoids
Learning Objectives
bull Draw and differentiate the waveform and the waveform envelope
bull Draw and differentiate the amplitude spectrum the phase spectrum and the spectrum envelope
bull Differential between short-term spectra and long-term average spectra
The ldquoenveloperdquo of a sound wave
bull Waveform envelopendash imaginary smooth line that follows the peak of the
amplitude of a sound pressure waveformbull Spectrum envelopendash Imaginary smooth line drawn on top of the
amplitude spectrum
Waveform envelope
From Hillenbrand
Waveform envelope
Time
>
Spectrum envelope
Frequency
Ampl
itude
Thought Question
Can an aperiodic and complex periodic sound have identical
spectrum envelopes
Amplitude Spectrum Window Size
bull ldquoshort-termrdquo vs ldquolong-term averagerdquo amplitude spectrum
ldquoInstantaneousrdquo Amplitude Spectra
(Long Term) Average Amplitude Spectrum
Learning Objectivesbull Describe how the amplitude spectrum and the spectrogram are
relatedbull Identify the axis units of the spectrogrambull Provide some advantages of the spectrogram over the
amplitude spectrumbull Distinguish between a wide band and narrow band spectrogram
and outline the different information each providesbull Distinguish between a harmonic and a formant on a
spectrogrambull Be able to draw stylized (highly simplified) spectrograms based
on spectra and spectrum envelopes
The Spectrogram
Rotate90 degrees
F
AF
A
Building a spectrogram
Rotate it so thatThe amplitude isComing out of thepage
F
A This is really narrow because it is a slice in time
F
Time
Building a spectrogram
Dark bands= amplitudePeaks
Time
Freq
uenc
y
Building a spectrogram
Two main types of spectrograms
bull Narrow-band spectrogramsndash Akin to amplitude spectrums ldquolined uprdquondash Frequency resolution is really sharp
bull Wide-band spectrogramsndash Akin to spectrum envelopes ldquolined uprdquondash Frequency resolution not so sharp
Highlights harmonic structure
Highlights spectrum envelope
Wide vs Narrow Band Spectrograms
Learning Objectives
bull Define an acoustic filterbull Draw and label a frequency response curvebull Draw and differentiate different types of acoustic
filtersbull Define terms such as cutoff frequency center
frequency roll off rate gain and bandwidthbull Define and draw a basic filter system and relate that
to the source-filter theory of speech production
What is an ldquoAcousticrdquo Filter
bull holds back (attenuates) certain sounds and lets other sounds through - selective
Why might we be interested in filters
bull Human vocal tract acts like a frequency selective acoustic filter
bull Human auditory system behaves as a frequency selective filter
bull helps us understand how speech is produced and perceived
Kinds of frequency selective filters
Low-pass filtersndash Lets low frequencies ldquopass throughrdquo and attenuates high
frequencies
High-pass filtersndash Lets high frequencies ldquopass throughrdquo and attenuates low
frequencies
Band-pass filtersndash Lets a particular frequency range ldquopass throughrdquo and
attenuates other frequencies
Low Pass Filters
Frequencylow high
Gai
n
+
-
High Pass Filters
Frequencylow high
Gai
n
+
-
Band Pass Filter
Frequencylow high
Gai
n
+
-
Frequency Response Curve (FRC)
Frequencylow high
Gai
n
+
-
Center frequency
lower cutofffrequency
upper cutoff frequency
passband
3 dB
Operation of a filter on a signal
NOTE Amplitude spectrum describes a soundFrequency response curve describes a filter
Learning Objectivesbull Define resonance free and forced vibrationbull Describe how the pendulum and spring mass models can
help explain resonancebull Outline how mass and stiffness influences the resonant
frequency of a mass spring systembull Outline how acoustic resonators behave like acoustic filtersbull Calculate resonant frequencies of a uniform tube based on
its physical dimensionsbull Describe how the wavelength of the sound determines the
resonant frequency of tube
Free vibration
bull objects tend to vibrate at a characteristic or resonant frequency (RF)
Forced vibration
bull A vibrating system can force a nearby system into vibration
bull The efficiency with which this is accomplished is related to the similarity in the resonant frequency (RF) of the two systems
Forced vibration
bull If the RF of the two systems are the same the amplitude of forced vibration will be large
bull If the RF of the two systems are quite different the amplitude of forced vibration will be small or nonexistent
Resonance refers to
bull The tendency for an object to vibrate at a particular frequency or frequencies
bull The ability of a vibrating system to force another system into vibration
Back to the mass spring model
bull Vibratory frequency of the mass spring determined byndash Massndash Stiffness of the spring
httpphetcoloradoeduensimulationmass-spring-lab
Acoustic Resonance
bull Ideas from mechanical resonance also applies to acoustic systems
bull Acoustic chambers will transmit sound frequencies with more or less efficiency depending upon the physical characteristics
bull Therefore they act as filters passing through (and even amplifying) some frequencies and attentuating others
Acoustic Resonance
bull And since they act as filters they have most of the same features of a filter even though we might use different names
bull Center frequency is often termed the resonant frequency
bull Frequency response curve often termed the resonance curve
Helmholtz Resonator
Actions of a Helmholtz Resonator
Stephen M Tasko
Other Acoustic Resonators Tube Resonators
bull Uniform tubes Factors that influence resonancendash Lengthndash Cross-sectional area along its lengthndash Whether it is closed at either or both ends
Uniform tube closed at one end
Uniform tube closed at one end
Stephen M Tasko
Uniform tube closed at one end
First resonance or formant
F1 = c4lWhere
c=speed of sound (35000 cmsec)l = length of the tube
males ~ 175 cmfemales ~ 14 cm
Higher resonantformant frequencies are odd multiples of F1
For examplebull F1 = (c4l )1
bull F2 = (c4l )3
bull F3 = (c4l )5
Comparing Helmholtz and tube resonators
Resonator Features
Sharply tuned Broadly tuned
Resonator Features
An example of the resonance characteristics of the human vocal tract
Frequency
Gain
SPPA 4030 Speech Science
Topic 1 The Speech Chain
The Speech Chain (Denes amp Pinson 1993)
What information is embedded in the speech signal
Branches of science employed to understand speech communication
Physical Quantities Review An Independent Learning Activity
Assignment 1
Topic 2 The Source-Filter Theory of Speech Production An Intr
Producing Speech
Source-Filter Theory of Speech Production
Vocal tract is a tube that can vary its shape
Source Filter Theory
Same Source Different Filter
Different Source Same Filters
Different Source Same Filters (Human)
Different Source Same Filters (Human) (2)
Different Source Same Filters (Human) (3)
Different Source Same Filters (Human) (4)
Different Source Same Filters (Non-Human)
Different Source Same Filters (Non-Human) (2)
Different Source Same Filters (Non-Human) If it quacks like a
Source Filter Theory Applied Alaryngeal Speech
Source-Filter Theory Applied Esophageal Insufflation Test
Source-Filter Theory Applied Tracheoesophageal (TE) Speech
Source Filter Theory Applied The Talkbox
Source-Filter Theory Applied The Talkbox
Topic 3 A Brief Review of Physical Acoustics
Spring Mass Model
What is sound
Sound-conducting media
Model of air molecule vibration (Time 1)
Model of air molecule vibration (Time 2)
Model of air molecule vibration (Time 3)
Model of air molecule vibration (Time 4)
Model of air molecule vibration (Time 5)
Model of air molecule vibration
Wave action of molecular motion
Amplitude waveform
Amplitude waveform (2)
Where is pressure in this model
Pressure waveform
Measuring Sound
Measuring Sound Signal Amplitude
Measuring Sound Signal Amplitude (2)
What units do we use to measure signal amplitude
Brief Review The decibel scale
Absolute vs relative measurement
Typical reference values
Howeverhellip
Linear vs logarithmic
Linear vs logarithmic (2)
Logarithmic Scale
Logarithmic Scale (2)
Combining the idea of logarithmic and relativehellip
Intensity vs Pressure
Extending the formula to pressure
Measuring Sound Frequencyperiod
Measuring Sound Frequencyperiod (2)
Phase Uniform Circular Motion
Initiating a sound waves that differ only in phase
Spatial variation in pressure wave
Spatial variation in pressure wave
Spatial variation in pressure wave (2)
Relation between frequency and wavelength
Learning Objectives
Graphic representation of sound
Same sound different graphs
Classification of sounds
Simple periodic sound
Simple periodic sound Graphic appearance
Complex periodic sounds
Complex periodic sounds Graphic appearance
Complex periodic sounds Graphic appearance (2)
Glottal Source
Amplitude vs Phase Spectrum
Amplitude vs Phase Spectrum (2)
(Complex) Aperiodic sounds
Aperiodic sounds Graphic appearance
Aperiodic sounds Graphic appearance (2)
Analysis of complex waves
Learning Objectives (2)
The ldquoenveloperdquo of a sound wave
Waveform envelope
Waveform envelope (2)
Spectrum envelope
Thought Question
Amplitude Spectrum Window Size
ldquoInstantaneousrdquo Amplitude Spectra
(Long Term) Average Amplitude Spectrum
Slide 90
Learning Objectives (3)
The Spectrogram
Building a spectrogram
Building a spectrogram
Building a spectrogram (2)
Two main types of spectrograms
Wide vs Narrow Band Spectrograms
Learning Objectives (4)
What is an ldquoAcousticrdquo Filter
Why might we be interested in filters
Kinds of frequency selective filters
Low Pass Filters
High Pass Filters
Band Pass Filter
Frequency Response Curve (FRC)
Operation of a filter on a signal
Learning Objectives (5)
Free vibration
Forced vibration
Forced vibration (2)
Resonance refers to
Back to the mass spring model
Acoustic Resonance
Acoustic Resonance (2)
Helmholtz Resonator
Actions of a Helmholtz Resonator
Other Acoustic Resonators Tube Resonators
Uniform tube closed at one end
Uniform tube closed at one end (2)
Uniform tube closed at one end
Comparing Helmholtz and tube resonators
Slide 122
Slide 123
Intensity vs Pressure
bull Intensity is difficult to measurebull Pressure is easy to measure ndash a microphone is
a pressure measuring devicebull Intensity is proportionate to Pressure2
Extending the formula to pressure
Using some logrithmic tricks this translates our equation for the decibel to
dBSPL= (2)(10)log 10(Pm Pr) = 20log 10(Pm Pr)
Measuring Sound Frequencyperiod
Period (T) duration of a single cycleFrequency (F) rate that cycle repeats itself (1T)
bull Complex gt one frequency componentbull Aperiodic Does not repeat itselfbull Frequency components are not systematically
relatedbull May be ndash Continuousndash Transient
Aperiodic sounds Graphic appearance
bull Time domainndash no repeating pattern of pressure change
bull Frequency domainndash the spectrum is dense ndash No ldquopicket fencerdquo
bull Auditory impression sounds lsquonoisyrsquo
Aperiodic sounds Graphic appearance
From Hillenbrand
>
Analysis of complex wavesbull Waves can be summedbull Complex waves are the sum of simple wavesbull Fourier French Mathematician
ndash Any complex waveform may be formed by summing sinusoids of various frequency amplitude and phase
bull Fourier Analysisndash Provides a unique (only one) solution for a given sound signalndash Is reflected in the amplitude and phase spectrum of the signalndash Reveals the building blocks of complex waves which are sinusoids
Learning Objectives
bull Draw and differentiate the waveform and the waveform envelope
bull Draw and differentiate the amplitude spectrum the phase spectrum and the spectrum envelope
bull Differential between short-term spectra and long-term average spectra
The ldquoenveloperdquo of a sound wave
bull Waveform envelopendash imaginary smooth line that follows the peak of the
amplitude of a sound pressure waveformbull Spectrum envelopendash Imaginary smooth line drawn on top of the
amplitude spectrum
Waveform envelope
From Hillenbrand
Waveform envelope
Time
>
Spectrum envelope
Frequency
Ampl
itude
Thought Question
Can an aperiodic and complex periodic sound have identical
spectrum envelopes
Amplitude Spectrum Window Size
bull ldquoshort-termrdquo vs ldquolong-term averagerdquo amplitude spectrum
ldquoInstantaneousrdquo Amplitude Spectra
(Long Term) Average Amplitude Spectrum
Learning Objectivesbull Describe how the amplitude spectrum and the spectrogram are
relatedbull Identify the axis units of the spectrogrambull Provide some advantages of the spectrogram over the
amplitude spectrumbull Distinguish between a wide band and narrow band spectrogram
and outline the different information each providesbull Distinguish between a harmonic and a formant on a
spectrogrambull Be able to draw stylized (highly simplified) spectrograms based
on spectra and spectrum envelopes
The Spectrogram
Rotate90 degrees
F
AF
A
Building a spectrogram
Rotate it so thatThe amplitude isComing out of thepage
F
A This is really narrow because it is a slice in time
F
Time
Building a spectrogram
Dark bands= amplitudePeaks
Time
Freq
uenc
y
Building a spectrogram
Two main types of spectrograms
bull Narrow-band spectrogramsndash Akin to amplitude spectrums ldquolined uprdquondash Frequency resolution is really sharp
bull Wide-band spectrogramsndash Akin to spectrum envelopes ldquolined uprdquondash Frequency resolution not so sharp
Highlights harmonic structure
Highlights spectrum envelope
Wide vs Narrow Band Spectrograms
Learning Objectives
bull Define an acoustic filterbull Draw and label a frequency response curvebull Draw and differentiate different types of acoustic
filtersbull Define terms such as cutoff frequency center
frequency roll off rate gain and bandwidthbull Define and draw a basic filter system and relate that
to the source-filter theory of speech production
What is an ldquoAcousticrdquo Filter
bull holds back (attenuates) certain sounds and lets other sounds through - selective
Why might we be interested in filters
bull Human vocal tract acts like a frequency selective acoustic filter
bull Human auditory system behaves as a frequency selective filter
bull helps us understand how speech is produced and perceived
Kinds of frequency selective filters
Low-pass filtersndash Lets low frequencies ldquopass throughrdquo and attenuates high
frequencies
High-pass filtersndash Lets high frequencies ldquopass throughrdquo and attenuates low
frequencies
Band-pass filtersndash Lets a particular frequency range ldquopass throughrdquo and
attenuates other frequencies
Low Pass Filters
Frequencylow high
Gai
n
+
-
High Pass Filters
Frequencylow high
Gai
n
+
-
Band Pass Filter
Frequencylow high
Gai
n
+
-
Frequency Response Curve (FRC)
Frequencylow high
Gai
n
+
-
Center frequency
lower cutofffrequency
upper cutoff frequency
passband
3 dB
Operation of a filter on a signal
NOTE Amplitude spectrum describes a soundFrequency response curve describes a filter
Learning Objectivesbull Define resonance free and forced vibrationbull Describe how the pendulum and spring mass models can
help explain resonancebull Outline how mass and stiffness influences the resonant
frequency of a mass spring systembull Outline how acoustic resonators behave like acoustic filtersbull Calculate resonant frequencies of a uniform tube based on
its physical dimensionsbull Describe how the wavelength of the sound determines the
resonant frequency of tube
Free vibration
bull objects tend to vibrate at a characteristic or resonant frequency (RF)
Forced vibration
bull A vibrating system can force a nearby system into vibration
bull The efficiency with which this is accomplished is related to the similarity in the resonant frequency (RF) of the two systems
Forced vibration
bull If the RF of the two systems are the same the amplitude of forced vibration will be large
bull If the RF of the two systems are quite different the amplitude of forced vibration will be small or nonexistent
Resonance refers to
bull The tendency for an object to vibrate at a particular frequency or frequencies
bull The ability of a vibrating system to force another system into vibration
Back to the mass spring model
bull Vibratory frequency of the mass spring determined byndash Massndash Stiffness of the spring
httpphetcoloradoeduensimulationmass-spring-lab
Acoustic Resonance
bull Ideas from mechanical resonance also applies to acoustic systems
bull Acoustic chambers will transmit sound frequencies with more or less efficiency depending upon the physical characteristics
bull Therefore they act as filters passing through (and even amplifying) some frequencies and attentuating others
Acoustic Resonance
bull And since they act as filters they have most of the same features of a filter even though we might use different names
bull Center frequency is often termed the resonant frequency
bull Frequency response curve often termed the resonance curve
Helmholtz Resonator
Actions of a Helmholtz Resonator
Stephen M Tasko
Other Acoustic Resonators Tube Resonators
bull Uniform tubes Factors that influence resonancendash Lengthndash Cross-sectional area along its lengthndash Whether it is closed at either or both ends
Uniform tube closed at one end
Uniform tube closed at one end
Stephen M Tasko
Uniform tube closed at one end
First resonance or formant
F1 = c4lWhere
c=speed of sound (35000 cmsec)l = length of the tube
males ~ 175 cmfemales ~ 14 cm
Higher resonantformant frequencies are odd multiples of F1
For examplebull F1 = (c4l )1
bull F2 = (c4l )3
bull F3 = (c4l )5
Comparing Helmholtz and tube resonators
Resonator Features
Sharply tuned Broadly tuned
Resonator Features
An example of the resonance characteristics of the human vocal tract
Frequency
Gain
SPPA 4030 Speech Science
Topic 1 The Speech Chain
The Speech Chain (Denes amp Pinson 1993)
What information is embedded in the speech signal
Branches of science employed to understand speech communication
Physical Quantities Review An Independent Learning Activity
Assignment 1
Topic 2 The Source-Filter Theory of Speech Production An Intr
Producing Speech
Source-Filter Theory of Speech Production
Vocal tract is a tube that can vary its shape
Source Filter Theory
Same Source Different Filter
Different Source Same Filters
Different Source Same Filters (Human)
Different Source Same Filters (Human) (2)
Different Source Same Filters (Human) (3)
Different Source Same Filters (Human) (4)
Different Source Same Filters (Non-Human)
Different Source Same Filters (Non-Human) (2)
Different Source Same Filters (Non-Human) If it quacks like a
Source Filter Theory Applied Alaryngeal Speech
Source-Filter Theory Applied Esophageal Insufflation Test
Source-Filter Theory Applied Tracheoesophageal (TE) Speech
Source Filter Theory Applied The Talkbox
Source-Filter Theory Applied The Talkbox
Topic 3 A Brief Review of Physical Acoustics
Spring Mass Model
What is sound
Sound-conducting media
Model of air molecule vibration (Time 1)
Model of air molecule vibration (Time 2)
Model of air molecule vibration (Time 3)
Model of air molecule vibration (Time 4)
Model of air molecule vibration (Time 5)
Model of air molecule vibration
Wave action of molecular motion
Amplitude waveform
Amplitude waveform (2)
Where is pressure in this model
Pressure waveform
Measuring Sound
Measuring Sound Signal Amplitude
Measuring Sound Signal Amplitude (2)
What units do we use to measure signal amplitude
Brief Review The decibel scale
Absolute vs relative measurement
Typical reference values
Howeverhellip
Linear vs logarithmic
Linear vs logarithmic (2)
Logarithmic Scale
Logarithmic Scale (2)
Combining the idea of logarithmic and relativehellip
Intensity vs Pressure
Extending the formula to pressure
Measuring Sound Frequencyperiod
Measuring Sound Frequencyperiod (2)
Phase Uniform Circular Motion
Initiating a sound waves that differ only in phase
Spatial variation in pressure wave
Spatial variation in pressure wave
Spatial variation in pressure wave (2)
Relation between frequency and wavelength
Learning Objectives
Graphic representation of sound
Same sound different graphs
Classification of sounds
Simple periodic sound
Simple periodic sound Graphic appearance
Complex periodic sounds
Complex periodic sounds Graphic appearance
Complex periodic sounds Graphic appearance (2)
Glottal Source
Amplitude vs Phase Spectrum
Amplitude vs Phase Spectrum (2)
(Complex) Aperiodic sounds
Aperiodic sounds Graphic appearance
Aperiodic sounds Graphic appearance (2)
Analysis of complex waves
Learning Objectives (2)
The ldquoenveloperdquo of a sound wave
Waveform envelope
Waveform envelope (2)
Spectrum envelope
Thought Question
Amplitude Spectrum Window Size
ldquoInstantaneousrdquo Amplitude Spectra
(Long Term) Average Amplitude Spectrum
Slide 90
Learning Objectives (3)
The Spectrogram
Building a spectrogram
Building a spectrogram
Building a spectrogram (2)
Two main types of spectrograms
Wide vs Narrow Band Spectrograms
Learning Objectives (4)
What is an ldquoAcousticrdquo Filter
Why might we be interested in filters
Kinds of frequency selective filters
Low Pass Filters
High Pass Filters
Band Pass Filter
Frequency Response Curve (FRC)
Operation of a filter on a signal
Learning Objectives (5)
Free vibration
Forced vibration
Forced vibration (2)
Resonance refers to
Back to the mass spring model
Acoustic Resonance
Acoustic Resonance (2)
Helmholtz Resonator
Actions of a Helmholtz Resonator
Other Acoustic Resonators Tube Resonators
Uniform tube closed at one end
Uniform tube closed at one end (2)
Uniform tube closed at one end
Comparing Helmholtz and tube resonators
Slide 122
Slide 123
Extending the formula to pressure
Using some logrithmic tricks this translates our equation for the decibel to
dBSPL= (2)(10)log 10(Pm Pr) = 20log 10(Pm Pr)
Measuring Sound Frequencyperiod
Period (T) duration of a single cycleFrequency (F) rate that cycle repeats itself (1T)
bull Complex gt one frequency componentbull Aperiodic Does not repeat itselfbull Frequency components are not systematically
relatedbull May be ndash Continuousndash Transient
Aperiodic sounds Graphic appearance
bull Time domainndash no repeating pattern of pressure change
bull Frequency domainndash the spectrum is dense ndash No ldquopicket fencerdquo
bull Auditory impression sounds lsquonoisyrsquo
Aperiodic sounds Graphic appearance
From Hillenbrand
>
Analysis of complex wavesbull Waves can be summedbull Complex waves are the sum of simple wavesbull Fourier French Mathematician
ndash Any complex waveform may be formed by summing sinusoids of various frequency amplitude and phase
bull Fourier Analysisndash Provides a unique (only one) solution for a given sound signalndash Is reflected in the amplitude and phase spectrum of the signalndash Reveals the building blocks of complex waves which are sinusoids
Learning Objectives
bull Draw and differentiate the waveform and the waveform envelope
bull Draw and differentiate the amplitude spectrum the phase spectrum and the spectrum envelope
bull Differential between short-term spectra and long-term average spectra
The ldquoenveloperdquo of a sound wave
bull Waveform envelopendash imaginary smooth line that follows the peak of the
amplitude of a sound pressure waveformbull Spectrum envelopendash Imaginary smooth line drawn on top of the
amplitude spectrum
Waveform envelope
From Hillenbrand
Waveform envelope
Time
>
Spectrum envelope
Frequency
Ampl
itude
Thought Question
Can an aperiodic and complex periodic sound have identical
spectrum envelopes
Amplitude Spectrum Window Size
bull ldquoshort-termrdquo vs ldquolong-term averagerdquo amplitude spectrum
ldquoInstantaneousrdquo Amplitude Spectra
(Long Term) Average Amplitude Spectrum
Learning Objectivesbull Describe how the amplitude spectrum and the spectrogram are
relatedbull Identify the axis units of the spectrogrambull Provide some advantages of the spectrogram over the
amplitude spectrumbull Distinguish between a wide band and narrow band spectrogram
and outline the different information each providesbull Distinguish between a harmonic and a formant on a
spectrogrambull Be able to draw stylized (highly simplified) spectrograms based
on spectra and spectrum envelopes
The Spectrogram
Rotate90 degrees
F
AF
A
Building a spectrogram
Rotate it so thatThe amplitude isComing out of thepage
F
A This is really narrow because it is a slice in time
F
Time
Building a spectrogram
Dark bands= amplitudePeaks
Time
Freq
uenc
y
Building a spectrogram
Two main types of spectrograms
bull Narrow-band spectrogramsndash Akin to amplitude spectrums ldquolined uprdquondash Frequency resolution is really sharp
bull Wide-band spectrogramsndash Akin to spectrum envelopes ldquolined uprdquondash Frequency resolution not so sharp
Highlights harmonic structure
Highlights spectrum envelope
Wide vs Narrow Band Spectrograms
Learning Objectives
bull Define an acoustic filterbull Draw and label a frequency response curvebull Draw and differentiate different types of acoustic
filtersbull Define terms such as cutoff frequency center
frequency roll off rate gain and bandwidthbull Define and draw a basic filter system and relate that
to the source-filter theory of speech production
What is an ldquoAcousticrdquo Filter
bull holds back (attenuates) certain sounds and lets other sounds through - selective
Why might we be interested in filters
bull Human vocal tract acts like a frequency selective acoustic filter
bull Human auditory system behaves as a frequency selective filter
bull helps us understand how speech is produced and perceived
Kinds of frequency selective filters
Low-pass filtersndash Lets low frequencies ldquopass throughrdquo and attenuates high
frequencies
High-pass filtersndash Lets high frequencies ldquopass throughrdquo and attenuates low
frequencies
Band-pass filtersndash Lets a particular frequency range ldquopass throughrdquo and
attenuates other frequencies
Low Pass Filters
Frequencylow high
Gai
n
+
-
High Pass Filters
Frequencylow high
Gai
n
+
-
Band Pass Filter
Frequencylow high
Gai
n
+
-
Frequency Response Curve (FRC)
Frequencylow high
Gai
n
+
-
Center frequency
lower cutofffrequency
upper cutoff frequency
passband
3 dB
Operation of a filter on a signal
NOTE Amplitude spectrum describes a soundFrequency response curve describes a filter
Learning Objectivesbull Define resonance free and forced vibrationbull Describe how the pendulum and spring mass models can
help explain resonancebull Outline how mass and stiffness influences the resonant
frequency of a mass spring systembull Outline how acoustic resonators behave like acoustic filtersbull Calculate resonant frequencies of a uniform tube based on
its physical dimensionsbull Describe how the wavelength of the sound determines the
resonant frequency of tube
Free vibration
bull objects tend to vibrate at a characteristic or resonant frequency (RF)
Forced vibration
bull A vibrating system can force a nearby system into vibration
bull The efficiency with which this is accomplished is related to the similarity in the resonant frequency (RF) of the two systems
Forced vibration
bull If the RF of the two systems are the same the amplitude of forced vibration will be large
bull If the RF of the two systems are quite different the amplitude of forced vibration will be small or nonexistent
Resonance refers to
bull The tendency for an object to vibrate at a particular frequency or frequencies
bull The ability of a vibrating system to force another system into vibration
Back to the mass spring model
bull Vibratory frequency of the mass spring determined byndash Massndash Stiffness of the spring
httpphetcoloradoeduensimulationmass-spring-lab
Acoustic Resonance
bull Ideas from mechanical resonance also applies to acoustic systems
bull Acoustic chambers will transmit sound frequencies with more or less efficiency depending upon the physical characteristics
bull Therefore they act as filters passing through (and even amplifying) some frequencies and attentuating others
Acoustic Resonance
bull And since they act as filters they have most of the same features of a filter even though we might use different names
bull Center frequency is often termed the resonant frequency
bull Frequency response curve often termed the resonance curve
Helmholtz Resonator
Actions of a Helmholtz Resonator
Stephen M Tasko
Other Acoustic Resonators Tube Resonators
bull Uniform tubes Factors that influence resonancendash Lengthndash Cross-sectional area along its lengthndash Whether it is closed at either or both ends
Uniform tube closed at one end
Uniform tube closed at one end
Stephen M Tasko
Uniform tube closed at one end
First resonance or formant
F1 = c4lWhere
c=speed of sound (35000 cmsec)l = length of the tube
males ~ 175 cmfemales ~ 14 cm
Higher resonantformant frequencies are odd multiples of F1
For examplebull F1 = (c4l )1
bull F2 = (c4l )3
bull F3 = (c4l )5
Comparing Helmholtz and tube resonators
Resonator Features
Sharply tuned Broadly tuned
Resonator Features
An example of the resonance characteristics of the human vocal tract
Frequency
Gain
SPPA 4030 Speech Science
Topic 1 The Speech Chain
The Speech Chain (Denes amp Pinson 1993)
What information is embedded in the speech signal
Branches of science employed to understand speech communication
Physical Quantities Review An Independent Learning Activity
Assignment 1
Topic 2 The Source-Filter Theory of Speech Production An Intr
Producing Speech
Source-Filter Theory of Speech Production
Vocal tract is a tube that can vary its shape
Source Filter Theory
Same Source Different Filter
Different Source Same Filters
Different Source Same Filters (Human)
Different Source Same Filters (Human) (2)
Different Source Same Filters (Human) (3)
Different Source Same Filters (Human) (4)
Different Source Same Filters (Non-Human)
Different Source Same Filters (Non-Human) (2)
Different Source Same Filters (Non-Human) If it quacks like a
Source Filter Theory Applied Alaryngeal Speech
Source-Filter Theory Applied Esophageal Insufflation Test
Source-Filter Theory Applied Tracheoesophageal (TE) Speech
Source Filter Theory Applied The Talkbox
Source-Filter Theory Applied The Talkbox
Topic 3 A Brief Review of Physical Acoustics
Spring Mass Model
What is sound
Sound-conducting media
Model of air molecule vibration (Time 1)
Model of air molecule vibration (Time 2)
Model of air molecule vibration (Time 3)
Model of air molecule vibration (Time 4)
Model of air molecule vibration (Time 5)
Model of air molecule vibration
Wave action of molecular motion
Amplitude waveform
Amplitude waveform (2)
Where is pressure in this model
Pressure waveform
Measuring Sound
Measuring Sound Signal Amplitude
Measuring Sound Signal Amplitude (2)
What units do we use to measure signal amplitude
Brief Review The decibel scale
Absolute vs relative measurement
Typical reference values
Howeverhellip
Linear vs logarithmic
Linear vs logarithmic (2)
Logarithmic Scale
Logarithmic Scale (2)
Combining the idea of logarithmic and relativehellip
Intensity vs Pressure
Extending the formula to pressure
Measuring Sound Frequencyperiod
Measuring Sound Frequencyperiod (2)
Phase Uniform Circular Motion
Initiating a sound waves that differ only in phase
Spatial variation in pressure wave
Spatial variation in pressure wave
Spatial variation in pressure wave (2)
Relation between frequency and wavelength
Learning Objectives
Graphic representation of sound
Same sound different graphs
Classification of sounds
Simple periodic sound
Simple periodic sound Graphic appearance
Complex periodic sounds
Complex periodic sounds Graphic appearance
Complex periodic sounds Graphic appearance (2)
Glottal Source
Amplitude vs Phase Spectrum
Amplitude vs Phase Spectrum (2)
(Complex) Aperiodic sounds
Aperiodic sounds Graphic appearance
Aperiodic sounds Graphic appearance (2)
Analysis of complex waves
Learning Objectives (2)
The ldquoenveloperdquo of a sound wave
Waveform envelope
Waveform envelope (2)
Spectrum envelope
Thought Question
Amplitude Spectrum Window Size
ldquoInstantaneousrdquo Amplitude Spectra
(Long Term) Average Amplitude Spectrum
Slide 90
Learning Objectives (3)
The Spectrogram
Building a spectrogram
Building a spectrogram
Building a spectrogram (2)
Two main types of spectrograms
Wide vs Narrow Band Spectrograms
Learning Objectives (4)
What is an ldquoAcousticrdquo Filter
Why might we be interested in filters
Kinds of frequency selective filters
Low Pass Filters
High Pass Filters
Band Pass Filter
Frequency Response Curve (FRC)
Operation of a filter on a signal
Learning Objectives (5)
Free vibration
Forced vibration
Forced vibration (2)
Resonance refers to
Back to the mass spring model
Acoustic Resonance
Acoustic Resonance (2)
Helmholtz Resonator
Actions of a Helmholtz Resonator
Other Acoustic Resonators Tube Resonators
Uniform tube closed at one end
Uniform tube closed at one end (2)
Uniform tube closed at one end
Comparing Helmholtz and tube resonators
Slide 122
Slide 123
Measuring Sound Frequencyperiod
Period (T) duration of a single cycleFrequency (F) rate that cycle repeats itself (1T)
bull Complex gt one frequency componentbull Aperiodic Does not repeat itselfbull Frequency components are not systematically
relatedbull May be ndash Continuousndash Transient
Aperiodic sounds Graphic appearance
bull Time domainndash no repeating pattern of pressure change
bull Frequency domainndash the spectrum is dense ndash No ldquopicket fencerdquo
bull Auditory impression sounds lsquonoisyrsquo
Aperiodic sounds Graphic appearance
From Hillenbrand
>
Analysis of complex wavesbull Waves can be summedbull Complex waves are the sum of simple wavesbull Fourier French Mathematician
ndash Any complex waveform may be formed by summing sinusoids of various frequency amplitude and phase
bull Fourier Analysisndash Provides a unique (only one) solution for a given sound signalndash Is reflected in the amplitude and phase spectrum of the signalndash Reveals the building blocks of complex waves which are sinusoids
Learning Objectives
bull Draw and differentiate the waveform and the waveform envelope
bull Draw and differentiate the amplitude spectrum the phase spectrum and the spectrum envelope
bull Differential between short-term spectra and long-term average spectra
The ldquoenveloperdquo of a sound wave
bull Waveform envelopendash imaginary smooth line that follows the peak of the
amplitude of a sound pressure waveformbull Spectrum envelopendash Imaginary smooth line drawn on top of the
amplitude spectrum
Waveform envelope
From Hillenbrand
Waveform envelope
Time
>
Spectrum envelope
Frequency
Ampl
itude
Thought Question
Can an aperiodic and complex periodic sound have identical
spectrum envelopes
Amplitude Spectrum Window Size
bull ldquoshort-termrdquo vs ldquolong-term averagerdquo amplitude spectrum
ldquoInstantaneousrdquo Amplitude Spectra
(Long Term) Average Amplitude Spectrum
Learning Objectivesbull Describe how the amplitude spectrum and the spectrogram are
relatedbull Identify the axis units of the spectrogrambull Provide some advantages of the spectrogram over the
amplitude spectrumbull Distinguish between a wide band and narrow band spectrogram
and outline the different information each providesbull Distinguish between a harmonic and a formant on a
spectrogrambull Be able to draw stylized (highly simplified) spectrograms based
on spectra and spectrum envelopes
The Spectrogram
Rotate90 degrees
F
AF
A
Building a spectrogram
Rotate it so thatThe amplitude isComing out of thepage
F
A This is really narrow because it is a slice in time
F
Time
Building a spectrogram
Dark bands= amplitudePeaks
Time
Freq
uenc
y
Building a spectrogram
Two main types of spectrograms
bull Narrow-band spectrogramsndash Akin to amplitude spectrums ldquolined uprdquondash Frequency resolution is really sharp
bull Wide-band spectrogramsndash Akin to spectrum envelopes ldquolined uprdquondash Frequency resolution not so sharp
Highlights harmonic structure
Highlights spectrum envelope
Wide vs Narrow Band Spectrograms
Learning Objectives
bull Define an acoustic filterbull Draw and label a frequency response curvebull Draw and differentiate different types of acoustic
filtersbull Define terms such as cutoff frequency center
frequency roll off rate gain and bandwidthbull Define and draw a basic filter system and relate that
to the source-filter theory of speech production
What is an ldquoAcousticrdquo Filter
bull holds back (attenuates) certain sounds and lets other sounds through - selective
Why might we be interested in filters
bull Human vocal tract acts like a frequency selective acoustic filter
bull Human auditory system behaves as a frequency selective filter
bull helps us understand how speech is produced and perceived
Kinds of frequency selective filters
Low-pass filtersndash Lets low frequencies ldquopass throughrdquo and attenuates high
frequencies
High-pass filtersndash Lets high frequencies ldquopass throughrdquo and attenuates low
frequencies
Band-pass filtersndash Lets a particular frequency range ldquopass throughrdquo and
attenuates other frequencies
Low Pass Filters
Frequencylow high
Gai
n
+
-
High Pass Filters
Frequencylow high
Gai
n
+
-
Band Pass Filter
Frequencylow high
Gai
n
+
-
Frequency Response Curve (FRC)
Frequencylow high
Gai
n
+
-
Center frequency
lower cutofffrequency
upper cutoff frequency
passband
3 dB
Operation of a filter on a signal
NOTE Amplitude spectrum describes a soundFrequency response curve describes a filter
Learning Objectivesbull Define resonance free and forced vibrationbull Describe how the pendulum and spring mass models can
help explain resonancebull Outline how mass and stiffness influences the resonant
frequency of a mass spring systembull Outline how acoustic resonators behave like acoustic filtersbull Calculate resonant frequencies of a uniform tube based on
its physical dimensionsbull Describe how the wavelength of the sound determines the
resonant frequency of tube
Free vibration
bull objects tend to vibrate at a characteristic or resonant frequency (RF)
Forced vibration
bull A vibrating system can force a nearby system into vibration
bull The efficiency with which this is accomplished is related to the similarity in the resonant frequency (RF) of the two systems
Forced vibration
bull If the RF of the two systems are the same the amplitude of forced vibration will be large
bull If the RF of the two systems are quite different the amplitude of forced vibration will be small or nonexistent
Resonance refers to
bull The tendency for an object to vibrate at a particular frequency or frequencies
bull The ability of a vibrating system to force another system into vibration
Back to the mass spring model
bull Vibratory frequency of the mass spring determined byndash Massndash Stiffness of the spring
httpphetcoloradoeduensimulationmass-spring-lab
Acoustic Resonance
bull Ideas from mechanical resonance also applies to acoustic systems
bull Acoustic chambers will transmit sound frequencies with more or less efficiency depending upon the physical characteristics
bull Therefore they act as filters passing through (and even amplifying) some frequencies and attentuating others
Acoustic Resonance
bull And since they act as filters they have most of the same features of a filter even though we might use different names
bull Center frequency is often termed the resonant frequency
bull Frequency response curve often termed the resonance curve
Helmholtz Resonator
Actions of a Helmholtz Resonator
Stephen M Tasko
Other Acoustic Resonators Tube Resonators
bull Uniform tubes Factors that influence resonancendash Lengthndash Cross-sectional area along its lengthndash Whether it is closed at either or both ends
Uniform tube closed at one end
Uniform tube closed at one end
Stephen M Tasko
Uniform tube closed at one end
First resonance or formant
F1 = c4lWhere
c=speed of sound (35000 cmsec)l = length of the tube
males ~ 175 cmfemales ~ 14 cm
Higher resonantformant frequencies are odd multiples of F1
For examplebull F1 = (c4l )1
bull F2 = (c4l )3
bull F3 = (c4l )5
Comparing Helmholtz and tube resonators
Resonator Features
Sharply tuned Broadly tuned
Resonator Features
An example of the resonance characteristics of the human vocal tract
Frequency
Gain
SPPA 4030 Speech Science
Topic 1 The Speech Chain
The Speech Chain (Denes amp Pinson 1993)
What information is embedded in the speech signal
Branches of science employed to understand speech communication
Physical Quantities Review An Independent Learning Activity
Assignment 1
Topic 2 The Source-Filter Theory of Speech Production An Intr
Producing Speech
Source-Filter Theory of Speech Production
Vocal tract is a tube that can vary its shape
Source Filter Theory
Same Source Different Filter
Different Source Same Filters
Different Source Same Filters (Human)
Different Source Same Filters (Human) (2)
Different Source Same Filters (Human) (3)
Different Source Same Filters (Human) (4)
Different Source Same Filters (Non-Human)
Different Source Same Filters (Non-Human) (2)
Different Source Same Filters (Non-Human) If it quacks like a
Source Filter Theory Applied Alaryngeal Speech
Source-Filter Theory Applied Esophageal Insufflation Test
Source-Filter Theory Applied Tracheoesophageal (TE) Speech
Source Filter Theory Applied The Talkbox
Source-Filter Theory Applied The Talkbox
Topic 3 A Brief Review of Physical Acoustics
Spring Mass Model
What is sound
Sound-conducting media
Model of air molecule vibration (Time 1)
Model of air molecule vibration (Time 2)
Model of air molecule vibration (Time 3)
Model of air molecule vibration (Time 4)
Model of air molecule vibration (Time 5)
Model of air molecule vibration
Wave action of molecular motion
Amplitude waveform
Amplitude waveform (2)
Where is pressure in this model
Pressure waveform
Measuring Sound
Measuring Sound Signal Amplitude
Measuring Sound Signal Amplitude (2)
What units do we use to measure signal amplitude
Brief Review The decibel scale
Absolute vs relative measurement
Typical reference values
Howeverhellip
Linear vs logarithmic
Linear vs logarithmic (2)
Logarithmic Scale
Logarithmic Scale (2)
Combining the idea of logarithmic and relativehellip
Intensity vs Pressure
Extending the formula to pressure
Measuring Sound Frequencyperiod
Measuring Sound Frequencyperiod (2)
Phase Uniform Circular Motion
Initiating a sound waves that differ only in phase
bull Complex gt one frequency componentbull Aperiodic Does not repeat itselfbull Frequency components are not systematically
relatedbull May be ndash Continuousndash Transient
Aperiodic sounds Graphic appearance
bull Time domainndash no repeating pattern of pressure change
bull Frequency domainndash the spectrum is dense ndash No ldquopicket fencerdquo
bull Auditory impression sounds lsquonoisyrsquo
Aperiodic sounds Graphic appearance
From Hillenbrand
>
Analysis of complex wavesbull Waves can be summedbull Complex waves are the sum of simple wavesbull Fourier French Mathematician
ndash Any complex waveform may be formed by summing sinusoids of various frequency amplitude and phase
bull Fourier Analysisndash Provides a unique (only one) solution for a given sound signalndash Is reflected in the amplitude and phase spectrum of the signalndash Reveals the building blocks of complex waves which are sinusoids
Learning Objectives
bull Draw and differentiate the waveform and the waveform envelope
bull Draw and differentiate the amplitude spectrum the phase spectrum and the spectrum envelope
bull Differential between short-term spectra and long-term average spectra
The ldquoenveloperdquo of a sound wave
bull Waveform envelopendash imaginary smooth line that follows the peak of the
amplitude of a sound pressure waveformbull Spectrum envelopendash Imaginary smooth line drawn on top of the
amplitude spectrum
Waveform envelope
From Hillenbrand
Waveform envelope
Time
>
Spectrum envelope
Frequency
Ampl
itude
Thought Question
Can an aperiodic and complex periodic sound have identical
spectrum envelopes
Amplitude Spectrum Window Size
bull ldquoshort-termrdquo vs ldquolong-term averagerdquo amplitude spectrum
ldquoInstantaneousrdquo Amplitude Spectra
(Long Term) Average Amplitude Spectrum
Learning Objectivesbull Describe how the amplitude spectrum and the spectrogram are
relatedbull Identify the axis units of the spectrogrambull Provide some advantages of the spectrogram over the
amplitude spectrumbull Distinguish between a wide band and narrow band spectrogram
and outline the different information each providesbull Distinguish between a harmonic and a formant on a
spectrogrambull Be able to draw stylized (highly simplified) spectrograms based
on spectra and spectrum envelopes
The Spectrogram
Rotate90 degrees
F
AF
A
Building a spectrogram
Rotate it so thatThe amplitude isComing out of thepage
F
A This is really narrow because it is a slice in time
F
Time
Building a spectrogram
Dark bands= amplitudePeaks
Time
Freq
uenc
y
Building a spectrogram
Two main types of spectrograms
bull Narrow-band spectrogramsndash Akin to amplitude spectrums ldquolined uprdquondash Frequency resolution is really sharp
bull Wide-band spectrogramsndash Akin to spectrum envelopes ldquolined uprdquondash Frequency resolution not so sharp
Highlights harmonic structure
Highlights spectrum envelope
Wide vs Narrow Band Spectrograms
Learning Objectives
bull Define an acoustic filterbull Draw and label a frequency response curvebull Draw and differentiate different types of acoustic
filtersbull Define terms such as cutoff frequency center
frequency roll off rate gain and bandwidthbull Define and draw a basic filter system and relate that
to the source-filter theory of speech production
What is an ldquoAcousticrdquo Filter
bull holds back (attenuates) certain sounds and lets other sounds through - selective
Why might we be interested in filters
bull Human vocal tract acts like a frequency selective acoustic filter
bull Human auditory system behaves as a frequency selective filter
bull helps us understand how speech is produced and perceived
Kinds of frequency selective filters
Low-pass filtersndash Lets low frequencies ldquopass throughrdquo and attenuates high
frequencies
High-pass filtersndash Lets high frequencies ldquopass throughrdquo and attenuates low
frequencies
Band-pass filtersndash Lets a particular frequency range ldquopass throughrdquo and
attenuates other frequencies
Low Pass Filters
Frequencylow high
Gai
n
+
-
High Pass Filters
Frequencylow high
Gai
n
+
-
Band Pass Filter
Frequencylow high
Gai
n
+
-
Frequency Response Curve (FRC)
Frequencylow high
Gai
n
+
-
Center frequency
lower cutofffrequency
upper cutoff frequency
passband
3 dB
Operation of a filter on a signal
NOTE Amplitude spectrum describes a soundFrequency response curve describes a filter
Learning Objectivesbull Define resonance free and forced vibrationbull Describe how the pendulum and spring mass models can
help explain resonancebull Outline how mass and stiffness influences the resonant
frequency of a mass spring systembull Outline how acoustic resonators behave like acoustic filtersbull Calculate resonant frequencies of a uniform tube based on
its physical dimensionsbull Describe how the wavelength of the sound determines the
resonant frequency of tube
Free vibration
bull objects tend to vibrate at a characteristic or resonant frequency (RF)
Forced vibration
bull A vibrating system can force a nearby system into vibration
bull The efficiency with which this is accomplished is related to the similarity in the resonant frequency (RF) of the two systems
Forced vibration
bull If the RF of the two systems are the same the amplitude of forced vibration will be large
bull If the RF of the two systems are quite different the amplitude of forced vibration will be small or nonexistent
Resonance refers to
bull The tendency for an object to vibrate at a particular frequency or frequencies
bull The ability of a vibrating system to force another system into vibration
Back to the mass spring model
bull Vibratory frequency of the mass spring determined byndash Massndash Stiffness of the spring
httpphetcoloradoeduensimulationmass-spring-lab
Acoustic Resonance
bull Ideas from mechanical resonance also applies to acoustic systems
bull Acoustic chambers will transmit sound frequencies with more or less efficiency depending upon the physical characteristics
bull Therefore they act as filters passing through (and even amplifying) some frequencies and attentuating others
Acoustic Resonance
bull And since they act as filters they have most of the same features of a filter even though we might use different names
bull Center frequency is often termed the resonant frequency
bull Frequency response curve often termed the resonance curve
Helmholtz Resonator
Actions of a Helmholtz Resonator
Stephen M Tasko
Other Acoustic Resonators Tube Resonators
bull Uniform tubes Factors that influence resonancendash Lengthndash Cross-sectional area along its lengthndash Whether it is closed at either or both ends
Uniform tube closed at one end
Uniform tube closed at one end
Stephen M Tasko
Uniform tube closed at one end
First resonance or formant
F1 = c4lWhere
c=speed of sound (35000 cmsec)l = length of the tube
males ~ 175 cmfemales ~ 14 cm
Higher resonantformant frequencies are odd multiples of F1
For examplebull F1 = (c4l )1
bull F2 = (c4l )3
bull F3 = (c4l )5
Comparing Helmholtz and tube resonators
Resonator Features
Sharply tuned Broadly tuned
Resonator Features
An example of the resonance characteristics of the human vocal tract
Frequency
Gain
SPPA 4030 Speech Science
Topic 1 The Speech Chain
The Speech Chain (Denes amp Pinson 1993)
What information is embedded in the speech signal
Branches of science employed to understand speech communication
Physical Quantities Review An Independent Learning Activity
Assignment 1
Topic 2 The Source-Filter Theory of Speech Production An Intr
Producing Speech
Source-Filter Theory of Speech Production
Vocal tract is a tube that can vary its shape
Source Filter Theory
Same Source Different Filter
Different Source Same Filters
Different Source Same Filters (Human)
Different Source Same Filters (Human) (2)
Different Source Same Filters (Human) (3)
Different Source Same Filters (Human) (4)
Different Source Same Filters (Non-Human)
Different Source Same Filters (Non-Human) (2)
Different Source Same Filters (Non-Human) If it quacks like a
Source Filter Theory Applied Alaryngeal Speech
Source-Filter Theory Applied Esophageal Insufflation Test
Source-Filter Theory Applied Tracheoesophageal (TE) Speech
Source Filter Theory Applied The Talkbox
Source-Filter Theory Applied The Talkbox
Topic 3 A Brief Review of Physical Acoustics
Spring Mass Model
What is sound
Sound-conducting media
Model of air molecule vibration (Time 1)
Model of air molecule vibration (Time 2)
Model of air molecule vibration (Time 3)
Model of air molecule vibration (Time 4)
Model of air molecule vibration (Time 5)
Model of air molecule vibration
Wave action of molecular motion
Amplitude waveform
Amplitude waveform (2)
Where is pressure in this model
Pressure waveform
Measuring Sound
Measuring Sound Signal Amplitude
Measuring Sound Signal Amplitude (2)
What units do we use to measure signal amplitude
Brief Review The decibel scale
Absolute vs relative measurement
Typical reference values
Howeverhellip
Linear vs logarithmic
Linear vs logarithmic (2)
Logarithmic Scale
Logarithmic Scale (2)
Combining the idea of logarithmic and relativehellip
Intensity vs Pressure
Extending the formula to pressure
Measuring Sound Frequencyperiod
Measuring Sound Frequencyperiod (2)
Phase Uniform Circular Motion
Initiating a sound waves that differ only in phase
Spatial variation in pressure wave
Spatial variation in pressure wave
Spatial variation in pressure wave (2)
Relation between frequency and wavelength
Learning Objectives
Graphic representation of sound
Same sound different graphs
Classification of sounds
Simple periodic sound
Simple periodic sound Graphic appearance
Complex periodic sounds
Complex periodic sounds Graphic appearance
Complex periodic sounds Graphic appearance (2)
Glottal Source
Amplitude vs Phase Spectrum
Amplitude vs Phase Spectrum (2)
(Complex) Aperiodic sounds
Aperiodic sounds Graphic appearance
Aperiodic sounds Graphic appearance (2)
Analysis of complex waves
Learning Objectives (2)
The ldquoenveloperdquo of a sound wave
Waveform envelope
Waveform envelope (2)
Spectrum envelope
Thought Question
Amplitude Spectrum Window Size
ldquoInstantaneousrdquo Amplitude Spectra
(Long Term) Average Amplitude Spectrum
Slide 90
Learning Objectives (3)
The Spectrogram
Building a spectrogram
Building a spectrogram
Building a spectrogram (2)
Two main types of spectrograms
Wide vs Narrow Band Spectrograms
Learning Objectives (4)
What is an ldquoAcousticrdquo Filter
Why might we be interested in filters
Kinds of frequency selective filters
Low Pass Filters
High Pass Filters
Band Pass Filter
Frequency Response Curve (FRC)
Operation of a filter on a signal
Learning Objectives (5)
Free vibration
Forced vibration
Forced vibration (2)
Resonance refers to
Back to the mass spring model
Acoustic Resonance
Acoustic Resonance (2)
Helmholtz Resonator
Actions of a Helmholtz Resonator
Other Acoustic Resonators Tube Resonators
Uniform tube closed at one end
Uniform tube closed at one end (2)
Uniform tube closed at one end
Comparing Helmholtz and tube resonators
Slide 122
Slide 123
Phase Uniform Circular Motion
Initiating a sound waves that differ only in phase
A force is applied to molecule at frequency f and time t
same force applied at frequency f at time t+a where a lt the period of vibration
Spatial variation in pressure wave
wavelength () is the distance covering adjacent high and low pressure regions
Spatial variation in pressure wave
Time1
2
3
4
5
Spatial variation in pressure wave
Relation between frequency and wavelength
=cF where
wavelengthF is the frequencyc is sound speed in medium (35000 cmsec)
Learning Objectivesbull Draw and describe time-domain and frequency-domain
representation of soundbull Distinguish between simple and complex sound sounds with
regard to physical characteristics and graphical representations
bull Distinguish between periodic and aperiodic sounds with specific emphasis on terms such as fundamental frequencyperiod harmonics and overtones
bull Distinguish between continuous and transient sounds bull Describe how waves sum define Fouriers theorem and be
able to describe the basics of Fourier analysis
Graphic representation of sound
bull Time domainndash Called a waveformndash Amplitude plotted as
a function of time
bull Frequency domainndash Called a spectrumndash Amplitude spectrumbull amplitude vs frequency
ndash Phase spectrumbull phase vs frequency
ndash May be measured using a variety of ldquowindowrdquo sizes
Same sound different graphs
Time domain
Frequency domain
From Hillenbrand
Classification of sounds
bull Number of frequency componentsndash Simplendash Complex
bull Relationship of frequency componentsndash Periodicndash Aperiodic
bull Durationndash Continuousndash Transient
Simple periodic sound
bull Simple one frequency componentbull Periodic repeating patternbull Completely characterized byndash amplitudendash period (frequency)ndash phase
bull Other names sinusoid simple harmonic motion pure tone
Simple periodic sound Graphic appearance
From Hillenbrand
Complex periodic sounds
bull Complex gt one frequency componentbull Periodic repeating patternbull Continuousbull Frequencies components have a special relation
ndash Lowest frequency fundamental frequencybull Symbol fo
bull Frequency component with longest periodndash Higher frequency components harmonics
bull integer (whole number) multiples of the fo
Complex periodic sounds Graphic appearance
bull Time domainndash repeating pattern of pressure changendash within the cycle things look complex
bull Frequency domain ndash spectral peaks at evenly spaced frequency
bull Complex gt one frequency componentbull Aperiodic Does not repeat itselfbull Frequency components are not systematically
relatedbull May be ndash Continuousndash Transient
Aperiodic sounds Graphic appearance
bull Time domainndash no repeating pattern of pressure change
bull Frequency domainndash the spectrum is dense ndash No ldquopicket fencerdquo
bull Auditory impression sounds lsquonoisyrsquo
Aperiodic sounds Graphic appearance
From Hillenbrand
>
Analysis of complex wavesbull Waves can be summedbull Complex waves are the sum of simple wavesbull Fourier French Mathematician
ndash Any complex waveform may be formed by summing sinusoids of various frequency amplitude and phase
bull Fourier Analysisndash Provides a unique (only one) solution for a given sound signalndash Is reflected in the amplitude and phase spectrum of the signalndash Reveals the building blocks of complex waves which are sinusoids
Learning Objectives
bull Draw and differentiate the waveform and the waveform envelope
bull Draw and differentiate the amplitude spectrum the phase spectrum and the spectrum envelope
bull Differential between short-term spectra and long-term average spectra
The ldquoenveloperdquo of a sound wave
bull Waveform envelopendash imaginary smooth line that follows the peak of the
amplitude of a sound pressure waveformbull Spectrum envelopendash Imaginary smooth line drawn on top of the
amplitude spectrum
Waveform envelope
From Hillenbrand
Waveform envelope
Time
>
Spectrum envelope
Frequency
Ampl
itude
Thought Question
Can an aperiodic and complex periodic sound have identical
spectrum envelopes
Amplitude Spectrum Window Size
bull ldquoshort-termrdquo vs ldquolong-term averagerdquo amplitude spectrum
ldquoInstantaneousrdquo Amplitude Spectra
(Long Term) Average Amplitude Spectrum
Learning Objectivesbull Describe how the amplitude spectrum and the spectrogram are
relatedbull Identify the axis units of the spectrogrambull Provide some advantages of the spectrogram over the
amplitude spectrumbull Distinguish between a wide band and narrow band spectrogram
and outline the different information each providesbull Distinguish between a harmonic and a formant on a
spectrogrambull Be able to draw stylized (highly simplified) spectrograms based
on spectra and spectrum envelopes
The Spectrogram
Rotate90 degrees
F
AF
A
Building a spectrogram
Rotate it so thatThe amplitude isComing out of thepage
F
A This is really narrow because it is a slice in time
F
Time
Building a spectrogram
Dark bands= amplitudePeaks
Time
Freq
uenc
y
Building a spectrogram
Two main types of spectrograms
bull Narrow-band spectrogramsndash Akin to amplitude spectrums ldquolined uprdquondash Frequency resolution is really sharp
bull Wide-band spectrogramsndash Akin to spectrum envelopes ldquolined uprdquondash Frequency resolution not so sharp
Highlights harmonic structure
Highlights spectrum envelope
Wide vs Narrow Band Spectrograms
Learning Objectives
bull Define an acoustic filterbull Draw and label a frequency response curvebull Draw and differentiate different types of acoustic
filtersbull Define terms such as cutoff frequency center
frequency roll off rate gain and bandwidthbull Define and draw a basic filter system and relate that
to the source-filter theory of speech production
What is an ldquoAcousticrdquo Filter
bull holds back (attenuates) certain sounds and lets other sounds through - selective
Why might we be interested in filters
bull Human vocal tract acts like a frequency selective acoustic filter
bull Human auditory system behaves as a frequency selective filter
bull helps us understand how speech is produced and perceived
Kinds of frequency selective filters
Low-pass filtersndash Lets low frequencies ldquopass throughrdquo and attenuates high
frequencies
High-pass filtersndash Lets high frequencies ldquopass throughrdquo and attenuates low
frequencies
Band-pass filtersndash Lets a particular frequency range ldquopass throughrdquo and
attenuates other frequencies
Low Pass Filters
Frequencylow high
Gai
n
+
-
High Pass Filters
Frequencylow high
Gai
n
+
-
Band Pass Filter
Frequencylow high
Gai
n
+
-
Frequency Response Curve (FRC)
Frequencylow high
Gai
n
+
-
Center frequency
lower cutofffrequency
upper cutoff frequency
passband
3 dB
Operation of a filter on a signal
NOTE Amplitude spectrum describes a soundFrequency response curve describes a filter
Learning Objectivesbull Define resonance free and forced vibrationbull Describe how the pendulum and spring mass models can
help explain resonancebull Outline how mass and stiffness influences the resonant
frequency of a mass spring systembull Outline how acoustic resonators behave like acoustic filtersbull Calculate resonant frequencies of a uniform tube based on
its physical dimensionsbull Describe how the wavelength of the sound determines the
resonant frequency of tube
Free vibration
bull objects tend to vibrate at a characteristic or resonant frequency (RF)
Forced vibration
bull A vibrating system can force a nearby system into vibration
bull The efficiency with which this is accomplished is related to the similarity in the resonant frequency (RF) of the two systems
Forced vibration
bull If the RF of the two systems are the same the amplitude of forced vibration will be large
bull If the RF of the two systems are quite different the amplitude of forced vibration will be small or nonexistent
Resonance refers to
bull The tendency for an object to vibrate at a particular frequency or frequencies
bull The ability of a vibrating system to force another system into vibration
Back to the mass spring model
bull Vibratory frequency of the mass spring determined byndash Massndash Stiffness of the spring
httpphetcoloradoeduensimulationmass-spring-lab
Acoustic Resonance
bull Ideas from mechanical resonance also applies to acoustic systems
bull Acoustic chambers will transmit sound frequencies with more or less efficiency depending upon the physical characteristics
bull Therefore they act as filters passing through (and even amplifying) some frequencies and attentuating others
Acoustic Resonance
bull And since they act as filters they have most of the same features of a filter even though we might use different names
bull Center frequency is often termed the resonant frequency
bull Frequency response curve often termed the resonance curve
Helmholtz Resonator
Actions of a Helmholtz Resonator
Stephen M Tasko
Other Acoustic Resonators Tube Resonators
bull Uniform tubes Factors that influence resonancendash Lengthndash Cross-sectional area along its lengthndash Whether it is closed at either or both ends
Uniform tube closed at one end
Uniform tube closed at one end
Stephen M Tasko
Uniform tube closed at one end
First resonance or formant
F1 = c4lWhere
c=speed of sound (35000 cmsec)l = length of the tube
males ~ 175 cmfemales ~ 14 cm
Higher resonantformant frequencies are odd multiples of F1
For examplebull F1 = (c4l )1
bull F2 = (c4l )3
bull F3 = (c4l )5
Comparing Helmholtz and tube resonators
Resonator Features
Sharply tuned Broadly tuned
Resonator Features
An example of the resonance characteristics of the human vocal tract
Frequency
Gain
SPPA 4030 Speech Science
Topic 1 The Speech Chain
The Speech Chain (Denes amp Pinson 1993)
What information is embedded in the speech signal
Branches of science employed to understand speech communication
Physical Quantities Review An Independent Learning Activity
Assignment 1
Topic 2 The Source-Filter Theory of Speech Production An Intr
Producing Speech
Source-Filter Theory of Speech Production
Vocal tract is a tube that can vary its shape
Source Filter Theory
Same Source Different Filter
Different Source Same Filters
Different Source Same Filters (Human)
Different Source Same Filters (Human) (2)
Different Source Same Filters (Human) (3)
Different Source Same Filters (Human) (4)
Different Source Same Filters (Non-Human)
Different Source Same Filters (Non-Human) (2)
Different Source Same Filters (Non-Human) If it quacks like a
Source Filter Theory Applied Alaryngeal Speech
Source-Filter Theory Applied Esophageal Insufflation Test
Source-Filter Theory Applied Tracheoesophageal (TE) Speech
Source Filter Theory Applied The Talkbox
Source-Filter Theory Applied The Talkbox
Topic 3 A Brief Review of Physical Acoustics
Spring Mass Model
What is sound
Sound-conducting media
Model of air molecule vibration (Time 1)
Model of air molecule vibration (Time 2)
Model of air molecule vibration (Time 3)
Model of air molecule vibration (Time 4)
Model of air molecule vibration (Time 5)
Model of air molecule vibration
Wave action of molecular motion
Amplitude waveform
Amplitude waveform (2)
Where is pressure in this model
Pressure waveform
Measuring Sound
Measuring Sound Signal Amplitude
Measuring Sound Signal Amplitude (2)
What units do we use to measure signal amplitude
Brief Review The decibel scale
Absolute vs relative measurement
Typical reference values
Howeverhellip
Linear vs logarithmic
Linear vs logarithmic (2)
Logarithmic Scale
Logarithmic Scale (2)
Combining the idea of logarithmic and relativehellip
Intensity vs Pressure
Extending the formula to pressure
Measuring Sound Frequencyperiod
Measuring Sound Frequencyperiod (2)
Phase Uniform Circular Motion
Initiating a sound waves that differ only in phase
Spatial variation in pressure wave
Spatial variation in pressure wave
Spatial variation in pressure wave (2)
Relation between frequency and wavelength
Learning Objectives
Graphic representation of sound
Same sound different graphs
Classification of sounds
Simple periodic sound
Simple periodic sound Graphic appearance
Complex periodic sounds
Complex periodic sounds Graphic appearance
Complex periodic sounds Graphic appearance (2)
Glottal Source
Amplitude vs Phase Spectrum
Amplitude vs Phase Spectrum (2)
(Complex) Aperiodic sounds
Aperiodic sounds Graphic appearance
Aperiodic sounds Graphic appearance (2)
Analysis of complex waves
Learning Objectives (2)
The ldquoenveloperdquo of a sound wave
Waveform envelope
Waveform envelope (2)
Spectrum envelope
Thought Question
Amplitude Spectrum Window Size
ldquoInstantaneousrdquo Amplitude Spectra
(Long Term) Average Amplitude Spectrum
Slide 90
Learning Objectives (3)
The Spectrogram
Building a spectrogram
Building a spectrogram
Building a spectrogram (2)
Two main types of spectrograms
Wide vs Narrow Band Spectrograms
Learning Objectives (4)
What is an ldquoAcousticrdquo Filter
Why might we be interested in filters
Kinds of frequency selective filters
Low Pass Filters
High Pass Filters
Band Pass Filter
Frequency Response Curve (FRC)
Operation of a filter on a signal
Learning Objectives (5)
Free vibration
Forced vibration
Forced vibration (2)
Resonance refers to
Back to the mass spring model
Acoustic Resonance
Acoustic Resonance (2)
Helmholtz Resonator
Actions of a Helmholtz Resonator
Other Acoustic Resonators Tube Resonators
Uniform tube closed at one end
Uniform tube closed at one end (2)
Uniform tube closed at one end
Comparing Helmholtz and tube resonators
Slide 122
Slide 123
Initiating a sound waves that differ only in phase
A force is applied to molecule at frequency f and time t
same force applied at frequency f at time t+a where a lt the period of vibration
Spatial variation in pressure wave
wavelength () is the distance covering adjacent high and low pressure regions
Spatial variation in pressure wave
Time1
2
3
4
5
Spatial variation in pressure wave
Relation between frequency and wavelength
=cF where
wavelengthF is the frequencyc is sound speed in medium (35000 cmsec)
Learning Objectivesbull Draw and describe time-domain and frequency-domain
representation of soundbull Distinguish between simple and complex sound sounds with
regard to physical characteristics and graphical representations
bull Distinguish between periodic and aperiodic sounds with specific emphasis on terms such as fundamental frequencyperiod harmonics and overtones
bull Distinguish between continuous and transient sounds bull Describe how waves sum define Fouriers theorem and be
able to describe the basics of Fourier analysis
Graphic representation of sound
bull Time domainndash Called a waveformndash Amplitude plotted as
a function of time
bull Frequency domainndash Called a spectrumndash Amplitude spectrumbull amplitude vs frequency
ndash Phase spectrumbull phase vs frequency
ndash May be measured using a variety of ldquowindowrdquo sizes
Same sound different graphs
Time domain
Frequency domain
From Hillenbrand
Classification of sounds
bull Number of frequency componentsndash Simplendash Complex
bull Relationship of frequency componentsndash Periodicndash Aperiodic
bull Durationndash Continuousndash Transient
Simple periodic sound
bull Simple one frequency componentbull Periodic repeating patternbull Completely characterized byndash amplitudendash period (frequency)ndash phase
bull Other names sinusoid simple harmonic motion pure tone
Simple periodic sound Graphic appearance
From Hillenbrand
Complex periodic sounds
bull Complex gt one frequency componentbull Periodic repeating patternbull Continuousbull Frequencies components have a special relation
ndash Lowest frequency fundamental frequencybull Symbol fo
bull Frequency component with longest periodndash Higher frequency components harmonics
bull integer (whole number) multiples of the fo
Complex periodic sounds Graphic appearance
bull Time domainndash repeating pattern of pressure changendash within the cycle things look complex
bull Frequency domain ndash spectral peaks at evenly spaced frequency
bull Complex gt one frequency componentbull Aperiodic Does not repeat itselfbull Frequency components are not systematically
relatedbull May be ndash Continuousndash Transient
Aperiodic sounds Graphic appearance
bull Time domainndash no repeating pattern of pressure change
bull Frequency domainndash the spectrum is dense ndash No ldquopicket fencerdquo
bull Auditory impression sounds lsquonoisyrsquo
Aperiodic sounds Graphic appearance
From Hillenbrand
>
Analysis of complex wavesbull Waves can be summedbull Complex waves are the sum of simple wavesbull Fourier French Mathematician
ndash Any complex waveform may be formed by summing sinusoids of various frequency amplitude and phase
bull Fourier Analysisndash Provides a unique (only one) solution for a given sound signalndash Is reflected in the amplitude and phase spectrum of the signalndash Reveals the building blocks of complex waves which are sinusoids
Learning Objectives
bull Draw and differentiate the waveform and the waveform envelope
bull Draw and differentiate the amplitude spectrum the phase spectrum and the spectrum envelope
bull Differential between short-term spectra and long-term average spectra
The ldquoenveloperdquo of a sound wave
bull Waveform envelopendash imaginary smooth line that follows the peak of the
amplitude of a sound pressure waveformbull Spectrum envelopendash Imaginary smooth line drawn on top of the
amplitude spectrum
Waveform envelope
From Hillenbrand
Waveform envelope
Time
>
Spectrum envelope
Frequency
Ampl
itude
Thought Question
Can an aperiodic and complex periodic sound have identical
spectrum envelopes
Amplitude Spectrum Window Size
bull ldquoshort-termrdquo vs ldquolong-term averagerdquo amplitude spectrum
ldquoInstantaneousrdquo Amplitude Spectra
(Long Term) Average Amplitude Spectrum
Learning Objectivesbull Describe how the amplitude spectrum and the spectrogram are
relatedbull Identify the axis units of the spectrogrambull Provide some advantages of the spectrogram over the
amplitude spectrumbull Distinguish between a wide band and narrow band spectrogram
and outline the different information each providesbull Distinguish between a harmonic and a formant on a
spectrogrambull Be able to draw stylized (highly simplified) spectrograms based
on spectra and spectrum envelopes
The Spectrogram
Rotate90 degrees
F
AF
A
Building a spectrogram
Rotate it so thatThe amplitude isComing out of thepage
F
A This is really narrow because it is a slice in time
F
Time
Building a spectrogram
Dark bands= amplitudePeaks
Time
Freq
uenc
y
Building a spectrogram
Two main types of spectrograms
bull Narrow-band spectrogramsndash Akin to amplitude spectrums ldquolined uprdquondash Frequency resolution is really sharp
bull Wide-band spectrogramsndash Akin to spectrum envelopes ldquolined uprdquondash Frequency resolution not so sharp
Highlights harmonic structure
Highlights spectrum envelope
Wide vs Narrow Band Spectrograms
Learning Objectives
bull Define an acoustic filterbull Draw and label a frequency response curvebull Draw and differentiate different types of acoustic
filtersbull Define terms such as cutoff frequency center
frequency roll off rate gain and bandwidthbull Define and draw a basic filter system and relate that
to the source-filter theory of speech production
What is an ldquoAcousticrdquo Filter
bull holds back (attenuates) certain sounds and lets other sounds through - selective
Why might we be interested in filters
bull Human vocal tract acts like a frequency selective acoustic filter
bull Human auditory system behaves as a frequency selective filter
bull helps us understand how speech is produced and perceived
Kinds of frequency selective filters
Low-pass filtersndash Lets low frequencies ldquopass throughrdquo and attenuates high
frequencies
High-pass filtersndash Lets high frequencies ldquopass throughrdquo and attenuates low
frequencies
Band-pass filtersndash Lets a particular frequency range ldquopass throughrdquo and
attenuates other frequencies
Low Pass Filters
Frequencylow high
Gai
n
+
-
High Pass Filters
Frequencylow high
Gai
n
+
-
Band Pass Filter
Frequencylow high
Gai
n
+
-
Frequency Response Curve (FRC)
Frequencylow high
Gai
n
+
-
Center frequency
lower cutofffrequency
upper cutoff frequency
passband
3 dB
Operation of a filter on a signal
NOTE Amplitude spectrum describes a soundFrequency response curve describes a filter
Learning Objectivesbull Define resonance free and forced vibrationbull Describe how the pendulum and spring mass models can
help explain resonancebull Outline how mass and stiffness influences the resonant
frequency of a mass spring systembull Outline how acoustic resonators behave like acoustic filtersbull Calculate resonant frequencies of a uniform tube based on
its physical dimensionsbull Describe how the wavelength of the sound determines the
resonant frequency of tube
Free vibration
bull objects tend to vibrate at a characteristic or resonant frequency (RF)
Forced vibration
bull A vibrating system can force a nearby system into vibration
bull The efficiency with which this is accomplished is related to the similarity in the resonant frequency (RF) of the two systems
Forced vibration
bull If the RF of the two systems are the same the amplitude of forced vibration will be large
bull If the RF of the two systems are quite different the amplitude of forced vibration will be small or nonexistent
Resonance refers to
bull The tendency for an object to vibrate at a particular frequency or frequencies
bull The ability of a vibrating system to force another system into vibration
Back to the mass spring model
bull Vibratory frequency of the mass spring determined byndash Massndash Stiffness of the spring
httpphetcoloradoeduensimulationmass-spring-lab
Acoustic Resonance
bull Ideas from mechanical resonance also applies to acoustic systems
bull Acoustic chambers will transmit sound frequencies with more or less efficiency depending upon the physical characteristics
bull Therefore they act as filters passing through (and even amplifying) some frequencies and attentuating others
Acoustic Resonance
bull And since they act as filters they have most of the same features of a filter even though we might use different names
bull Center frequency is often termed the resonant frequency
bull Frequency response curve often termed the resonance curve
Helmholtz Resonator
Actions of a Helmholtz Resonator
Stephen M Tasko
Other Acoustic Resonators Tube Resonators
bull Uniform tubes Factors that influence resonancendash Lengthndash Cross-sectional area along its lengthndash Whether it is closed at either or both ends
Uniform tube closed at one end
Uniform tube closed at one end
Stephen M Tasko
Uniform tube closed at one end
First resonance or formant
F1 = c4lWhere
c=speed of sound (35000 cmsec)l = length of the tube
males ~ 175 cmfemales ~ 14 cm
Higher resonantformant frequencies are odd multiples of F1
For examplebull F1 = (c4l )1
bull F2 = (c4l )3
bull F3 = (c4l )5
Comparing Helmholtz and tube resonators
Resonator Features
Sharply tuned Broadly tuned
Resonator Features
An example of the resonance characteristics of the human vocal tract
Frequency
Gain
SPPA 4030 Speech Science
Topic 1 The Speech Chain
The Speech Chain (Denes amp Pinson 1993)
What information is embedded in the speech signal
Branches of science employed to understand speech communication
Physical Quantities Review An Independent Learning Activity
Assignment 1
Topic 2 The Source-Filter Theory of Speech Production An Intr
Producing Speech
Source-Filter Theory of Speech Production
Vocal tract is a tube that can vary its shape
Source Filter Theory
Same Source Different Filter
Different Source Same Filters
Different Source Same Filters (Human)
Different Source Same Filters (Human) (2)
Different Source Same Filters (Human) (3)
Different Source Same Filters (Human) (4)
Different Source Same Filters (Non-Human)
Different Source Same Filters (Non-Human) (2)
Different Source Same Filters (Non-Human) If it quacks like a
Source Filter Theory Applied Alaryngeal Speech
Source-Filter Theory Applied Esophageal Insufflation Test
Source-Filter Theory Applied Tracheoesophageal (TE) Speech
Source Filter Theory Applied The Talkbox
Source-Filter Theory Applied The Talkbox
Topic 3 A Brief Review of Physical Acoustics
Spring Mass Model
What is sound
Sound-conducting media
Model of air molecule vibration (Time 1)
Model of air molecule vibration (Time 2)
Model of air molecule vibration (Time 3)
Model of air molecule vibration (Time 4)
Model of air molecule vibration (Time 5)
Model of air molecule vibration
Wave action of molecular motion
Amplitude waveform
Amplitude waveform (2)
Where is pressure in this model
Pressure waveform
Measuring Sound
Measuring Sound Signal Amplitude
Measuring Sound Signal Amplitude (2)
What units do we use to measure signal amplitude
Brief Review The decibel scale
Absolute vs relative measurement
Typical reference values
Howeverhellip
Linear vs logarithmic
Linear vs logarithmic (2)
Logarithmic Scale
Logarithmic Scale (2)
Combining the idea of logarithmic and relativehellip
Intensity vs Pressure
Extending the formula to pressure
Measuring Sound Frequencyperiod
Measuring Sound Frequencyperiod (2)
Phase Uniform Circular Motion
Initiating a sound waves that differ only in phase
Spatial variation in pressure wave
Spatial variation in pressure wave
Spatial variation in pressure wave (2)
Relation between frequency and wavelength
Learning Objectives
Graphic representation of sound
Same sound different graphs
Classification of sounds
Simple periodic sound
Simple periodic sound Graphic appearance
Complex periodic sounds
Complex periodic sounds Graphic appearance
Complex periodic sounds Graphic appearance (2)
Glottal Source
Amplitude vs Phase Spectrum
Amplitude vs Phase Spectrum (2)
(Complex) Aperiodic sounds
Aperiodic sounds Graphic appearance
Aperiodic sounds Graphic appearance (2)
Analysis of complex waves
Learning Objectives (2)
The ldquoenveloperdquo of a sound wave
Waveform envelope
Waveform envelope (2)
Spectrum envelope
Thought Question
Amplitude Spectrum Window Size
ldquoInstantaneousrdquo Amplitude Spectra
(Long Term) Average Amplitude Spectrum
Slide 90
Learning Objectives (3)
The Spectrogram
Building a spectrogram
Building a spectrogram
Building a spectrogram (2)
Two main types of spectrograms
Wide vs Narrow Band Spectrograms
Learning Objectives (4)
What is an ldquoAcousticrdquo Filter
Why might we be interested in filters
Kinds of frequency selective filters
Low Pass Filters
High Pass Filters
Band Pass Filter
Frequency Response Curve (FRC)
Operation of a filter on a signal
Learning Objectives (5)
Free vibration
Forced vibration
Forced vibration (2)
Resonance refers to
Back to the mass spring model
Acoustic Resonance
Acoustic Resonance (2)
Helmholtz Resonator
Actions of a Helmholtz Resonator
Other Acoustic Resonators Tube Resonators
Uniform tube closed at one end
Uniform tube closed at one end (2)
Uniform tube closed at one end
Comparing Helmholtz and tube resonators
Slide 122
Slide 123
Spatial variation in pressure wave
wavelength () is the distance covering adjacent high and low pressure regions
Spatial variation in pressure wave
Time1
2
3
4
5
Spatial variation in pressure wave
Relation between frequency and wavelength
=cF where
wavelengthF is the frequencyc is sound speed in medium (35000 cmsec)
Learning Objectivesbull Draw and describe time-domain and frequency-domain
representation of soundbull Distinguish between simple and complex sound sounds with
regard to physical characteristics and graphical representations
bull Distinguish between periodic and aperiodic sounds with specific emphasis on terms such as fundamental frequencyperiod harmonics and overtones
bull Distinguish between continuous and transient sounds bull Describe how waves sum define Fouriers theorem and be
able to describe the basics of Fourier analysis
Graphic representation of sound
bull Time domainndash Called a waveformndash Amplitude plotted as
a function of time
bull Frequency domainndash Called a spectrumndash Amplitude spectrumbull amplitude vs frequency
ndash Phase spectrumbull phase vs frequency
ndash May be measured using a variety of ldquowindowrdquo sizes
Same sound different graphs
Time domain
Frequency domain
From Hillenbrand
Classification of sounds
bull Number of frequency componentsndash Simplendash Complex
bull Relationship of frequency componentsndash Periodicndash Aperiodic
bull Durationndash Continuousndash Transient
Simple periodic sound
bull Simple one frequency componentbull Periodic repeating patternbull Completely characterized byndash amplitudendash period (frequency)ndash phase
bull Other names sinusoid simple harmonic motion pure tone
Simple periodic sound Graphic appearance
From Hillenbrand
Complex periodic sounds
bull Complex gt one frequency componentbull Periodic repeating patternbull Continuousbull Frequencies components have a special relation
ndash Lowest frequency fundamental frequencybull Symbol fo
bull Frequency component with longest periodndash Higher frequency components harmonics
bull integer (whole number) multiples of the fo
Complex periodic sounds Graphic appearance
bull Time domainndash repeating pattern of pressure changendash within the cycle things look complex
bull Frequency domain ndash spectral peaks at evenly spaced frequency
bull Complex gt one frequency componentbull Aperiodic Does not repeat itselfbull Frequency components are not systematically
relatedbull May be ndash Continuousndash Transient
Aperiodic sounds Graphic appearance
bull Time domainndash no repeating pattern of pressure change
bull Frequency domainndash the spectrum is dense ndash No ldquopicket fencerdquo
bull Auditory impression sounds lsquonoisyrsquo
Aperiodic sounds Graphic appearance
From Hillenbrand
>
Analysis of complex wavesbull Waves can be summedbull Complex waves are the sum of simple wavesbull Fourier French Mathematician
ndash Any complex waveform may be formed by summing sinusoids of various frequency amplitude and phase
bull Fourier Analysisndash Provides a unique (only one) solution for a given sound signalndash Is reflected in the amplitude and phase spectrum of the signalndash Reveals the building blocks of complex waves which are sinusoids
Learning Objectives
bull Draw and differentiate the waveform and the waveform envelope
bull Draw and differentiate the amplitude spectrum the phase spectrum and the spectrum envelope
bull Differential between short-term spectra and long-term average spectra
The ldquoenveloperdquo of a sound wave
bull Waveform envelopendash imaginary smooth line that follows the peak of the
amplitude of a sound pressure waveformbull Spectrum envelopendash Imaginary smooth line drawn on top of the
amplitude spectrum
Waveform envelope
From Hillenbrand
Waveform envelope
Time
>
Spectrum envelope
Frequency
Ampl
itude
Thought Question
Can an aperiodic and complex periodic sound have identical
spectrum envelopes
Amplitude Spectrum Window Size
bull ldquoshort-termrdquo vs ldquolong-term averagerdquo amplitude spectrum
ldquoInstantaneousrdquo Amplitude Spectra
(Long Term) Average Amplitude Spectrum
Learning Objectivesbull Describe how the amplitude spectrum and the spectrogram are
relatedbull Identify the axis units of the spectrogrambull Provide some advantages of the spectrogram over the
amplitude spectrumbull Distinguish between a wide band and narrow band spectrogram
and outline the different information each providesbull Distinguish between a harmonic and a formant on a
spectrogrambull Be able to draw stylized (highly simplified) spectrograms based
on spectra and spectrum envelopes
The Spectrogram
Rotate90 degrees
F
AF
A
Building a spectrogram
Rotate it so thatThe amplitude isComing out of thepage
F
A This is really narrow because it is a slice in time
F
Time
Building a spectrogram
Dark bands= amplitudePeaks
Time
Freq
uenc
y
Building a spectrogram
Two main types of spectrograms
bull Narrow-band spectrogramsndash Akin to amplitude spectrums ldquolined uprdquondash Frequency resolution is really sharp
bull Wide-band spectrogramsndash Akin to spectrum envelopes ldquolined uprdquondash Frequency resolution not so sharp
Highlights harmonic structure
Highlights spectrum envelope
Wide vs Narrow Band Spectrograms
Learning Objectives
bull Define an acoustic filterbull Draw and label a frequency response curvebull Draw and differentiate different types of acoustic
filtersbull Define terms such as cutoff frequency center
frequency roll off rate gain and bandwidthbull Define and draw a basic filter system and relate that
to the source-filter theory of speech production
What is an ldquoAcousticrdquo Filter
bull holds back (attenuates) certain sounds and lets other sounds through - selective
Why might we be interested in filters
bull Human vocal tract acts like a frequency selective acoustic filter
bull Human auditory system behaves as a frequency selective filter
bull helps us understand how speech is produced and perceived
Kinds of frequency selective filters
Low-pass filtersndash Lets low frequencies ldquopass throughrdquo and attenuates high
frequencies
High-pass filtersndash Lets high frequencies ldquopass throughrdquo and attenuates low
frequencies
Band-pass filtersndash Lets a particular frequency range ldquopass throughrdquo and
attenuates other frequencies
Low Pass Filters
Frequencylow high
Gai
n
+
-
High Pass Filters
Frequencylow high
Gai
n
+
-
Band Pass Filter
Frequencylow high
Gai
n
+
-
Frequency Response Curve (FRC)
Frequencylow high
Gai
n
+
-
Center frequency
lower cutofffrequency
upper cutoff frequency
passband
3 dB
Operation of a filter on a signal
NOTE Amplitude spectrum describes a soundFrequency response curve describes a filter
Learning Objectivesbull Define resonance free and forced vibrationbull Describe how the pendulum and spring mass models can
help explain resonancebull Outline how mass and stiffness influences the resonant
frequency of a mass spring systembull Outline how acoustic resonators behave like acoustic filtersbull Calculate resonant frequencies of a uniform tube based on
its physical dimensionsbull Describe how the wavelength of the sound determines the
resonant frequency of tube
Free vibration
bull objects tend to vibrate at a characteristic or resonant frequency (RF)
Forced vibration
bull A vibrating system can force a nearby system into vibration
bull The efficiency with which this is accomplished is related to the similarity in the resonant frequency (RF) of the two systems
Forced vibration
bull If the RF of the two systems are the same the amplitude of forced vibration will be large
bull If the RF of the two systems are quite different the amplitude of forced vibration will be small or nonexistent
Resonance refers to
bull The tendency for an object to vibrate at a particular frequency or frequencies
bull The ability of a vibrating system to force another system into vibration
Back to the mass spring model
bull Vibratory frequency of the mass spring determined byndash Massndash Stiffness of the spring
httpphetcoloradoeduensimulationmass-spring-lab
Acoustic Resonance
bull Ideas from mechanical resonance also applies to acoustic systems
bull Acoustic chambers will transmit sound frequencies with more or less efficiency depending upon the physical characteristics
bull Therefore they act as filters passing through (and even amplifying) some frequencies and attentuating others
Acoustic Resonance
bull And since they act as filters they have most of the same features of a filter even though we might use different names
bull Center frequency is often termed the resonant frequency
bull Frequency response curve often termed the resonance curve
Helmholtz Resonator
Actions of a Helmholtz Resonator
Stephen M Tasko
Other Acoustic Resonators Tube Resonators
bull Uniform tubes Factors that influence resonancendash Lengthndash Cross-sectional area along its lengthndash Whether it is closed at either or both ends
Uniform tube closed at one end
Uniform tube closed at one end
Stephen M Tasko
Uniform tube closed at one end
First resonance or formant
F1 = c4lWhere
c=speed of sound (35000 cmsec)l = length of the tube
males ~ 175 cmfemales ~ 14 cm
Higher resonantformant frequencies are odd multiples of F1
For examplebull F1 = (c4l )1
bull F2 = (c4l )3
bull F3 = (c4l )5
Comparing Helmholtz and tube resonators
Resonator Features
Sharply tuned Broadly tuned
Resonator Features
An example of the resonance characteristics of the human vocal tract
Frequency
Gain
SPPA 4030 Speech Science
Topic 1 The Speech Chain
The Speech Chain (Denes amp Pinson 1993)
What information is embedded in the speech signal
Branches of science employed to understand speech communication
Physical Quantities Review An Independent Learning Activity
Assignment 1
Topic 2 The Source-Filter Theory of Speech Production An Intr
Producing Speech
Source-Filter Theory of Speech Production
Vocal tract is a tube that can vary its shape
Source Filter Theory
Same Source Different Filter
Different Source Same Filters
Different Source Same Filters (Human)
Different Source Same Filters (Human) (2)
Different Source Same Filters (Human) (3)
Different Source Same Filters (Human) (4)
Different Source Same Filters (Non-Human)
Different Source Same Filters (Non-Human) (2)
Different Source Same Filters (Non-Human) If it quacks like a
Source Filter Theory Applied Alaryngeal Speech
Source-Filter Theory Applied Esophageal Insufflation Test
Source-Filter Theory Applied Tracheoesophageal (TE) Speech
Source Filter Theory Applied The Talkbox
Source-Filter Theory Applied The Talkbox
Topic 3 A Brief Review of Physical Acoustics
Spring Mass Model
What is sound
Sound-conducting media
Model of air molecule vibration (Time 1)
Model of air molecule vibration (Time 2)
Model of air molecule vibration (Time 3)
Model of air molecule vibration (Time 4)
Model of air molecule vibration (Time 5)
Model of air molecule vibration
Wave action of molecular motion
Amplitude waveform
Amplitude waveform (2)
Where is pressure in this model
Pressure waveform
Measuring Sound
Measuring Sound Signal Amplitude
Measuring Sound Signal Amplitude (2)
What units do we use to measure signal amplitude
Brief Review The decibel scale
Absolute vs relative measurement
Typical reference values
Howeverhellip
Linear vs logarithmic
Linear vs logarithmic (2)
Logarithmic Scale
Logarithmic Scale (2)
Combining the idea of logarithmic and relativehellip
Intensity vs Pressure
Extending the formula to pressure
Measuring Sound Frequencyperiod
Measuring Sound Frequencyperiod (2)
Phase Uniform Circular Motion
Initiating a sound waves that differ only in phase
Spatial variation in pressure wave
Spatial variation in pressure wave
Spatial variation in pressure wave (2)
Relation between frequency and wavelength
Learning Objectives
Graphic representation of sound
Same sound different graphs
Classification of sounds
Simple periodic sound
Simple periodic sound Graphic appearance
Complex periodic sounds
Complex periodic sounds Graphic appearance
Complex periodic sounds Graphic appearance (2)
Glottal Source
Amplitude vs Phase Spectrum
Amplitude vs Phase Spectrum (2)
(Complex) Aperiodic sounds
Aperiodic sounds Graphic appearance
Aperiodic sounds Graphic appearance (2)
Analysis of complex waves
Learning Objectives (2)
The ldquoenveloperdquo of a sound wave
Waveform envelope
Waveform envelope (2)
Spectrum envelope
Thought Question
Amplitude Spectrum Window Size
ldquoInstantaneousrdquo Amplitude Spectra
(Long Term) Average Amplitude Spectrum
Slide 90
Learning Objectives (3)
The Spectrogram
Building a spectrogram
Building a spectrogram
Building a spectrogram (2)
Two main types of spectrograms
Wide vs Narrow Band Spectrograms
Learning Objectives (4)
What is an ldquoAcousticrdquo Filter
Why might we be interested in filters
Kinds of frequency selective filters
Low Pass Filters
High Pass Filters
Band Pass Filter
Frequency Response Curve (FRC)
Operation of a filter on a signal
Learning Objectives (5)
Free vibration
Forced vibration
Forced vibration (2)
Resonance refers to
Back to the mass spring model
Acoustic Resonance
Acoustic Resonance (2)
Helmholtz Resonator
Actions of a Helmholtz Resonator
Other Acoustic Resonators Tube Resonators
Uniform tube closed at one end
Uniform tube closed at one end (2)
Uniform tube closed at one end
Comparing Helmholtz and tube resonators
Slide 122
Slide 123
Spatial variation in pressure wave
Time1
2
3
4
5
Spatial variation in pressure wave
Relation between frequency and wavelength
=cF where
wavelengthF is the frequencyc is sound speed in medium (35000 cmsec)
Learning Objectivesbull Draw and describe time-domain and frequency-domain
representation of soundbull Distinguish between simple and complex sound sounds with
regard to physical characteristics and graphical representations
bull Distinguish between periodic and aperiodic sounds with specific emphasis on terms such as fundamental frequencyperiod harmonics and overtones
bull Distinguish between continuous and transient sounds bull Describe how waves sum define Fouriers theorem and be
able to describe the basics of Fourier analysis
Graphic representation of sound
bull Time domainndash Called a waveformndash Amplitude plotted as
a function of time
bull Frequency domainndash Called a spectrumndash Amplitude spectrumbull amplitude vs frequency
ndash Phase spectrumbull phase vs frequency
ndash May be measured using a variety of ldquowindowrdquo sizes
Same sound different graphs
Time domain
Frequency domain
From Hillenbrand
Classification of sounds
bull Number of frequency componentsndash Simplendash Complex
bull Relationship of frequency componentsndash Periodicndash Aperiodic
bull Durationndash Continuousndash Transient
Simple periodic sound
bull Simple one frequency componentbull Periodic repeating patternbull Completely characterized byndash amplitudendash period (frequency)ndash phase
bull Other names sinusoid simple harmonic motion pure tone
Simple periodic sound Graphic appearance
From Hillenbrand
Complex periodic sounds
bull Complex gt one frequency componentbull Periodic repeating patternbull Continuousbull Frequencies components have a special relation
ndash Lowest frequency fundamental frequencybull Symbol fo
bull Frequency component with longest periodndash Higher frequency components harmonics
bull integer (whole number) multiples of the fo
Complex periodic sounds Graphic appearance
bull Time domainndash repeating pattern of pressure changendash within the cycle things look complex
bull Frequency domain ndash spectral peaks at evenly spaced frequency
bull Complex gt one frequency componentbull Aperiodic Does not repeat itselfbull Frequency components are not systematically
relatedbull May be ndash Continuousndash Transient
Aperiodic sounds Graphic appearance
bull Time domainndash no repeating pattern of pressure change
bull Frequency domainndash the spectrum is dense ndash No ldquopicket fencerdquo
bull Auditory impression sounds lsquonoisyrsquo
Aperiodic sounds Graphic appearance
From Hillenbrand
>
Analysis of complex wavesbull Waves can be summedbull Complex waves are the sum of simple wavesbull Fourier French Mathematician
ndash Any complex waveform may be formed by summing sinusoids of various frequency amplitude and phase
bull Fourier Analysisndash Provides a unique (only one) solution for a given sound signalndash Is reflected in the amplitude and phase spectrum of the signalndash Reveals the building blocks of complex waves which are sinusoids
Learning Objectives
bull Draw and differentiate the waveform and the waveform envelope
bull Draw and differentiate the amplitude spectrum the phase spectrum and the spectrum envelope
bull Differential between short-term spectra and long-term average spectra
The ldquoenveloperdquo of a sound wave
bull Waveform envelopendash imaginary smooth line that follows the peak of the
amplitude of a sound pressure waveformbull Spectrum envelopendash Imaginary smooth line drawn on top of the
amplitude spectrum
Waveform envelope
From Hillenbrand
Waveform envelope
Time
>
Spectrum envelope
Frequency
Ampl
itude
Thought Question
Can an aperiodic and complex periodic sound have identical
spectrum envelopes
Amplitude Spectrum Window Size
bull ldquoshort-termrdquo vs ldquolong-term averagerdquo amplitude spectrum
ldquoInstantaneousrdquo Amplitude Spectra
(Long Term) Average Amplitude Spectrum
Learning Objectivesbull Describe how the amplitude spectrum and the spectrogram are
relatedbull Identify the axis units of the spectrogrambull Provide some advantages of the spectrogram over the
amplitude spectrumbull Distinguish between a wide band and narrow band spectrogram
and outline the different information each providesbull Distinguish between a harmonic and a formant on a
spectrogrambull Be able to draw stylized (highly simplified) spectrograms based
on spectra and spectrum envelopes
The Spectrogram
Rotate90 degrees
F
AF
A
Building a spectrogram
Rotate it so thatThe amplitude isComing out of thepage
F
A This is really narrow because it is a slice in time
F
Time
Building a spectrogram
Dark bands= amplitudePeaks
Time
Freq
uenc
y
Building a spectrogram
Two main types of spectrograms
bull Narrow-band spectrogramsndash Akin to amplitude spectrums ldquolined uprdquondash Frequency resolution is really sharp
bull Wide-band spectrogramsndash Akin to spectrum envelopes ldquolined uprdquondash Frequency resolution not so sharp
Highlights harmonic structure
Highlights spectrum envelope
Wide vs Narrow Band Spectrograms
Learning Objectives
bull Define an acoustic filterbull Draw and label a frequency response curvebull Draw and differentiate different types of acoustic
filtersbull Define terms such as cutoff frequency center
frequency roll off rate gain and bandwidthbull Define and draw a basic filter system and relate that
to the source-filter theory of speech production
What is an ldquoAcousticrdquo Filter
bull holds back (attenuates) certain sounds and lets other sounds through - selective
Why might we be interested in filters
bull Human vocal tract acts like a frequency selective acoustic filter
bull Human auditory system behaves as a frequency selective filter
bull helps us understand how speech is produced and perceived
Kinds of frequency selective filters
Low-pass filtersndash Lets low frequencies ldquopass throughrdquo and attenuates high
frequencies
High-pass filtersndash Lets high frequencies ldquopass throughrdquo and attenuates low
frequencies
Band-pass filtersndash Lets a particular frequency range ldquopass throughrdquo and
attenuates other frequencies
Low Pass Filters
Frequencylow high
Gai
n
+
-
High Pass Filters
Frequencylow high
Gai
n
+
-
Band Pass Filter
Frequencylow high
Gai
n
+
-
Frequency Response Curve (FRC)
Frequencylow high
Gai
n
+
-
Center frequency
lower cutofffrequency
upper cutoff frequency
passband
3 dB
Operation of a filter on a signal
NOTE Amplitude spectrum describes a soundFrequency response curve describes a filter
Learning Objectivesbull Define resonance free and forced vibrationbull Describe how the pendulum and spring mass models can
help explain resonancebull Outline how mass and stiffness influences the resonant
frequency of a mass spring systembull Outline how acoustic resonators behave like acoustic filtersbull Calculate resonant frequencies of a uniform tube based on
its physical dimensionsbull Describe how the wavelength of the sound determines the
resonant frequency of tube
Free vibration
bull objects tend to vibrate at a characteristic or resonant frequency (RF)
Forced vibration
bull A vibrating system can force a nearby system into vibration
bull The efficiency with which this is accomplished is related to the similarity in the resonant frequency (RF) of the two systems
Forced vibration
bull If the RF of the two systems are the same the amplitude of forced vibration will be large
bull If the RF of the two systems are quite different the amplitude of forced vibration will be small or nonexistent
Resonance refers to
bull The tendency for an object to vibrate at a particular frequency or frequencies
bull The ability of a vibrating system to force another system into vibration
Back to the mass spring model
bull Vibratory frequency of the mass spring determined byndash Massndash Stiffness of the spring
httpphetcoloradoeduensimulationmass-spring-lab
Acoustic Resonance
bull Ideas from mechanical resonance also applies to acoustic systems
bull Acoustic chambers will transmit sound frequencies with more or less efficiency depending upon the physical characteristics
bull Therefore they act as filters passing through (and even amplifying) some frequencies and attentuating others
Acoustic Resonance
bull And since they act as filters they have most of the same features of a filter even though we might use different names
bull Center frequency is often termed the resonant frequency
bull Frequency response curve often termed the resonance curve
Helmholtz Resonator
Actions of a Helmholtz Resonator
Stephen M Tasko
Other Acoustic Resonators Tube Resonators
bull Uniform tubes Factors that influence resonancendash Lengthndash Cross-sectional area along its lengthndash Whether it is closed at either or both ends
Uniform tube closed at one end
Uniform tube closed at one end
Stephen M Tasko
Uniform tube closed at one end
First resonance or formant
F1 = c4lWhere
c=speed of sound (35000 cmsec)l = length of the tube
males ~ 175 cmfemales ~ 14 cm
Higher resonantformant frequencies are odd multiples of F1
For examplebull F1 = (c4l )1
bull F2 = (c4l )3
bull F3 = (c4l )5
Comparing Helmholtz and tube resonators
Resonator Features
Sharply tuned Broadly tuned
Resonator Features
An example of the resonance characteristics of the human vocal tract
Frequency
Gain
SPPA 4030 Speech Science
Topic 1 The Speech Chain
The Speech Chain (Denes amp Pinson 1993)
What information is embedded in the speech signal
Branches of science employed to understand speech communication
Physical Quantities Review An Independent Learning Activity
Assignment 1
Topic 2 The Source-Filter Theory of Speech Production An Intr
Producing Speech
Source-Filter Theory of Speech Production
Vocal tract is a tube that can vary its shape
Source Filter Theory
Same Source Different Filter
Different Source Same Filters
Different Source Same Filters (Human)
Different Source Same Filters (Human) (2)
Different Source Same Filters (Human) (3)
Different Source Same Filters (Human) (4)
Different Source Same Filters (Non-Human)
Different Source Same Filters (Non-Human) (2)
Different Source Same Filters (Non-Human) If it quacks like a
Source Filter Theory Applied Alaryngeal Speech
Source-Filter Theory Applied Esophageal Insufflation Test
Source-Filter Theory Applied Tracheoesophageal (TE) Speech
Source Filter Theory Applied The Talkbox
Source-Filter Theory Applied The Talkbox
Topic 3 A Brief Review of Physical Acoustics
Spring Mass Model
What is sound
Sound-conducting media
Model of air molecule vibration (Time 1)
Model of air molecule vibration (Time 2)
Model of air molecule vibration (Time 3)
Model of air molecule vibration (Time 4)
Model of air molecule vibration (Time 5)
Model of air molecule vibration
Wave action of molecular motion
Amplitude waveform
Amplitude waveform (2)
Where is pressure in this model
Pressure waveform
Measuring Sound
Measuring Sound Signal Amplitude
Measuring Sound Signal Amplitude (2)
What units do we use to measure signal amplitude
Brief Review The decibel scale
Absolute vs relative measurement
Typical reference values
Howeverhellip
Linear vs logarithmic
Linear vs logarithmic (2)
Logarithmic Scale
Logarithmic Scale (2)
Combining the idea of logarithmic and relativehellip
Intensity vs Pressure
Extending the formula to pressure
Measuring Sound Frequencyperiod
Measuring Sound Frequencyperiod (2)
Phase Uniform Circular Motion
Initiating a sound waves that differ only in phase
Spatial variation in pressure wave
Spatial variation in pressure wave
Spatial variation in pressure wave (2)
Relation between frequency and wavelength
Learning Objectives
Graphic representation of sound
Same sound different graphs
Classification of sounds
Simple periodic sound
Simple periodic sound Graphic appearance
Complex periodic sounds
Complex periodic sounds Graphic appearance
Complex periodic sounds Graphic appearance (2)
Glottal Source
Amplitude vs Phase Spectrum
Amplitude vs Phase Spectrum (2)
(Complex) Aperiodic sounds
Aperiodic sounds Graphic appearance
Aperiodic sounds Graphic appearance (2)
Analysis of complex waves
Learning Objectives (2)
The ldquoenveloperdquo of a sound wave
Waveform envelope
Waveform envelope (2)
Spectrum envelope
Thought Question
Amplitude Spectrum Window Size
ldquoInstantaneousrdquo Amplitude Spectra
(Long Term) Average Amplitude Spectrum
Slide 90
Learning Objectives (3)
The Spectrogram
Building a spectrogram
Building a spectrogram
Building a spectrogram (2)
Two main types of spectrograms
Wide vs Narrow Band Spectrograms
Learning Objectives (4)
What is an ldquoAcousticrdquo Filter
Why might we be interested in filters
Kinds of frequency selective filters
Low Pass Filters
High Pass Filters
Band Pass Filter
Frequency Response Curve (FRC)
Operation of a filter on a signal
Learning Objectives (5)
Free vibration
Forced vibration
Forced vibration (2)
Resonance refers to
Back to the mass spring model
Acoustic Resonance
Acoustic Resonance (2)
Helmholtz Resonator
Actions of a Helmholtz Resonator
Other Acoustic Resonators Tube Resonators
Uniform tube closed at one end
Uniform tube closed at one end (2)
Uniform tube closed at one end
Comparing Helmholtz and tube resonators
Slide 122
Slide 123
Spatial variation in pressure wave
Relation between frequency and wavelength
=cF where
wavelengthF is the frequencyc is sound speed in medium (35000 cmsec)
Learning Objectivesbull Draw and describe time-domain and frequency-domain
representation of soundbull Distinguish between simple and complex sound sounds with
regard to physical characteristics and graphical representations
bull Distinguish between periodic and aperiodic sounds with specific emphasis on terms such as fundamental frequencyperiod harmonics and overtones
bull Distinguish between continuous and transient sounds bull Describe how waves sum define Fouriers theorem and be
able to describe the basics of Fourier analysis
Graphic representation of sound
bull Time domainndash Called a waveformndash Amplitude plotted as
a function of time
bull Frequency domainndash Called a spectrumndash Amplitude spectrumbull amplitude vs frequency
ndash Phase spectrumbull phase vs frequency
ndash May be measured using a variety of ldquowindowrdquo sizes
Same sound different graphs
Time domain
Frequency domain
From Hillenbrand
Classification of sounds
bull Number of frequency componentsndash Simplendash Complex
bull Relationship of frequency componentsndash Periodicndash Aperiodic
bull Durationndash Continuousndash Transient
Simple periodic sound
bull Simple one frequency componentbull Periodic repeating patternbull Completely characterized byndash amplitudendash period (frequency)ndash phase
bull Other names sinusoid simple harmonic motion pure tone
Simple periodic sound Graphic appearance
From Hillenbrand
Complex periodic sounds
bull Complex gt one frequency componentbull Periodic repeating patternbull Continuousbull Frequencies components have a special relation
ndash Lowest frequency fundamental frequencybull Symbol fo
bull Frequency component with longest periodndash Higher frequency components harmonics
bull integer (whole number) multiples of the fo
Complex periodic sounds Graphic appearance
bull Time domainndash repeating pattern of pressure changendash within the cycle things look complex
bull Frequency domain ndash spectral peaks at evenly spaced frequency
bull Complex gt one frequency componentbull Aperiodic Does not repeat itselfbull Frequency components are not systematically
relatedbull May be ndash Continuousndash Transient
Aperiodic sounds Graphic appearance
bull Time domainndash no repeating pattern of pressure change
bull Frequency domainndash the spectrum is dense ndash No ldquopicket fencerdquo
bull Auditory impression sounds lsquonoisyrsquo
Aperiodic sounds Graphic appearance
From Hillenbrand
>
Analysis of complex wavesbull Waves can be summedbull Complex waves are the sum of simple wavesbull Fourier French Mathematician
ndash Any complex waveform may be formed by summing sinusoids of various frequency amplitude and phase
bull Fourier Analysisndash Provides a unique (only one) solution for a given sound signalndash Is reflected in the amplitude and phase spectrum of the signalndash Reveals the building blocks of complex waves which are sinusoids
Learning Objectives
bull Draw and differentiate the waveform and the waveform envelope
bull Draw and differentiate the amplitude spectrum the phase spectrum and the spectrum envelope
bull Differential between short-term spectra and long-term average spectra
The ldquoenveloperdquo of a sound wave
bull Waveform envelopendash imaginary smooth line that follows the peak of the
amplitude of a sound pressure waveformbull Spectrum envelopendash Imaginary smooth line drawn on top of the
amplitude spectrum
Waveform envelope
From Hillenbrand
Waveform envelope
Time
>
Spectrum envelope
Frequency
Ampl
itude
Thought Question
Can an aperiodic and complex periodic sound have identical
spectrum envelopes
Amplitude Spectrum Window Size
bull ldquoshort-termrdquo vs ldquolong-term averagerdquo amplitude spectrum
ldquoInstantaneousrdquo Amplitude Spectra
(Long Term) Average Amplitude Spectrum
Learning Objectivesbull Describe how the amplitude spectrum and the spectrogram are
relatedbull Identify the axis units of the spectrogrambull Provide some advantages of the spectrogram over the
amplitude spectrumbull Distinguish between a wide band and narrow band spectrogram
and outline the different information each providesbull Distinguish between a harmonic and a formant on a
spectrogrambull Be able to draw stylized (highly simplified) spectrograms based
on spectra and spectrum envelopes
The Spectrogram
Rotate90 degrees
F
AF
A
Building a spectrogram
Rotate it so thatThe amplitude isComing out of thepage
F
A This is really narrow because it is a slice in time
F
Time
Building a spectrogram
Dark bands= amplitudePeaks
Time
Freq
uenc
y
Building a spectrogram
Two main types of spectrograms
bull Narrow-band spectrogramsndash Akin to amplitude spectrums ldquolined uprdquondash Frequency resolution is really sharp
bull Wide-band spectrogramsndash Akin to spectrum envelopes ldquolined uprdquondash Frequency resolution not so sharp
Highlights harmonic structure
Highlights spectrum envelope
Wide vs Narrow Band Spectrograms
Learning Objectives
bull Define an acoustic filterbull Draw and label a frequency response curvebull Draw and differentiate different types of acoustic
filtersbull Define terms such as cutoff frequency center
frequency roll off rate gain and bandwidthbull Define and draw a basic filter system and relate that
to the source-filter theory of speech production
What is an ldquoAcousticrdquo Filter
bull holds back (attenuates) certain sounds and lets other sounds through - selective
Why might we be interested in filters
bull Human vocal tract acts like a frequency selective acoustic filter
bull Human auditory system behaves as a frequency selective filter
bull helps us understand how speech is produced and perceived
Kinds of frequency selective filters
Low-pass filtersndash Lets low frequencies ldquopass throughrdquo and attenuates high
frequencies
High-pass filtersndash Lets high frequencies ldquopass throughrdquo and attenuates low
frequencies
Band-pass filtersndash Lets a particular frequency range ldquopass throughrdquo and
attenuates other frequencies
Low Pass Filters
Frequencylow high
Gai
n
+
-
High Pass Filters
Frequencylow high
Gai
n
+
-
Band Pass Filter
Frequencylow high
Gai
n
+
-
Frequency Response Curve (FRC)
Frequencylow high
Gai
n
+
-
Center frequency
lower cutofffrequency
upper cutoff frequency
passband
3 dB
Operation of a filter on a signal
NOTE Amplitude spectrum describes a soundFrequency response curve describes a filter
Learning Objectivesbull Define resonance free and forced vibrationbull Describe how the pendulum and spring mass models can
help explain resonancebull Outline how mass and stiffness influences the resonant
frequency of a mass spring systembull Outline how acoustic resonators behave like acoustic filtersbull Calculate resonant frequencies of a uniform tube based on
its physical dimensionsbull Describe how the wavelength of the sound determines the
resonant frequency of tube
Free vibration
bull objects tend to vibrate at a characteristic or resonant frequency (RF)
Forced vibration
bull A vibrating system can force a nearby system into vibration
bull The efficiency with which this is accomplished is related to the similarity in the resonant frequency (RF) of the two systems
Forced vibration
bull If the RF of the two systems are the same the amplitude of forced vibration will be large
bull If the RF of the two systems are quite different the amplitude of forced vibration will be small or nonexistent
Resonance refers to
bull The tendency for an object to vibrate at a particular frequency or frequencies
bull The ability of a vibrating system to force another system into vibration
Back to the mass spring model
bull Vibratory frequency of the mass spring determined byndash Massndash Stiffness of the spring
httpphetcoloradoeduensimulationmass-spring-lab
Acoustic Resonance
bull Ideas from mechanical resonance also applies to acoustic systems
bull Acoustic chambers will transmit sound frequencies with more or less efficiency depending upon the physical characteristics
bull Therefore they act as filters passing through (and even amplifying) some frequencies and attentuating others
Acoustic Resonance
bull And since they act as filters they have most of the same features of a filter even though we might use different names
bull Center frequency is often termed the resonant frequency
bull Frequency response curve often termed the resonance curve
Helmholtz Resonator
Actions of a Helmholtz Resonator
Stephen M Tasko
Other Acoustic Resonators Tube Resonators
bull Uniform tubes Factors that influence resonancendash Lengthndash Cross-sectional area along its lengthndash Whether it is closed at either or both ends
Uniform tube closed at one end
Uniform tube closed at one end
Stephen M Tasko
Uniform tube closed at one end
First resonance or formant
F1 = c4lWhere
c=speed of sound (35000 cmsec)l = length of the tube
males ~ 175 cmfemales ~ 14 cm
Higher resonantformant frequencies are odd multiples of F1
For examplebull F1 = (c4l )1
bull F2 = (c4l )3
bull F3 = (c4l )5
Comparing Helmholtz and tube resonators
Resonator Features
Sharply tuned Broadly tuned
Resonator Features
An example of the resonance characteristics of the human vocal tract
Frequency
Gain
SPPA 4030 Speech Science
Topic 1 The Speech Chain
The Speech Chain (Denes amp Pinson 1993)
What information is embedded in the speech signal
Branches of science employed to understand speech communication
Physical Quantities Review An Independent Learning Activity
Assignment 1
Topic 2 The Source-Filter Theory of Speech Production An Intr
Producing Speech
Source-Filter Theory of Speech Production
Vocal tract is a tube that can vary its shape
Source Filter Theory
Same Source Different Filter
Different Source Same Filters
Different Source Same Filters (Human)
Different Source Same Filters (Human) (2)
Different Source Same Filters (Human) (3)
Different Source Same Filters (Human) (4)
Different Source Same Filters (Non-Human)
Different Source Same Filters (Non-Human) (2)
Different Source Same Filters (Non-Human) If it quacks like a
Source Filter Theory Applied Alaryngeal Speech
Source-Filter Theory Applied Esophageal Insufflation Test
Source-Filter Theory Applied Tracheoesophageal (TE) Speech
Source Filter Theory Applied The Talkbox
Source-Filter Theory Applied The Talkbox
Topic 3 A Brief Review of Physical Acoustics
Spring Mass Model
What is sound
Sound-conducting media
Model of air molecule vibration (Time 1)
Model of air molecule vibration (Time 2)
Model of air molecule vibration (Time 3)
Model of air molecule vibration (Time 4)
Model of air molecule vibration (Time 5)
Model of air molecule vibration
Wave action of molecular motion
Amplitude waveform
Amplitude waveform (2)
Where is pressure in this model
Pressure waveform
Measuring Sound
Measuring Sound Signal Amplitude
Measuring Sound Signal Amplitude (2)
What units do we use to measure signal amplitude
Brief Review The decibel scale
Absolute vs relative measurement
Typical reference values
Howeverhellip
Linear vs logarithmic
Linear vs logarithmic (2)
Logarithmic Scale
Logarithmic Scale (2)
Combining the idea of logarithmic and relativehellip
Intensity vs Pressure
Extending the formula to pressure
Measuring Sound Frequencyperiod
Measuring Sound Frequencyperiod (2)
Phase Uniform Circular Motion
Initiating a sound waves that differ only in phase
Spatial variation in pressure wave
Spatial variation in pressure wave
Spatial variation in pressure wave (2)
Relation between frequency and wavelength
Learning Objectives
Graphic representation of sound
Same sound different graphs
Classification of sounds
Simple periodic sound
Simple periodic sound Graphic appearance
Complex periodic sounds
Complex periodic sounds Graphic appearance
Complex periodic sounds Graphic appearance (2)
Glottal Source
Amplitude vs Phase Spectrum
Amplitude vs Phase Spectrum (2)
(Complex) Aperiodic sounds
Aperiodic sounds Graphic appearance
Aperiodic sounds Graphic appearance (2)
Analysis of complex waves
Learning Objectives (2)
The ldquoenveloperdquo of a sound wave
Waveform envelope
Waveform envelope (2)
Spectrum envelope
Thought Question
Amplitude Spectrum Window Size
ldquoInstantaneousrdquo Amplitude Spectra
(Long Term) Average Amplitude Spectrum
Slide 90
Learning Objectives (3)
The Spectrogram
Building a spectrogram
Building a spectrogram
Building a spectrogram (2)
Two main types of spectrograms
Wide vs Narrow Band Spectrograms
Learning Objectives (4)
What is an ldquoAcousticrdquo Filter
Why might we be interested in filters
Kinds of frequency selective filters
Low Pass Filters
High Pass Filters
Band Pass Filter
Frequency Response Curve (FRC)
Operation of a filter on a signal
Learning Objectives (5)
Free vibration
Forced vibration
Forced vibration (2)
Resonance refers to
Back to the mass spring model
Acoustic Resonance
Acoustic Resonance (2)
Helmholtz Resonator
Actions of a Helmholtz Resonator
Other Acoustic Resonators Tube Resonators
Uniform tube closed at one end
Uniform tube closed at one end (2)
Uniform tube closed at one end
Comparing Helmholtz and tube resonators
Slide 122
Slide 123
Relation between frequency and wavelength
=cF where
wavelengthF is the frequencyc is sound speed in medium (35000 cmsec)
Learning Objectivesbull Draw and describe time-domain and frequency-domain
representation of soundbull Distinguish between simple and complex sound sounds with
regard to physical characteristics and graphical representations
bull Distinguish between periodic and aperiodic sounds with specific emphasis on terms such as fundamental frequencyperiod harmonics and overtones
bull Distinguish between continuous and transient sounds bull Describe how waves sum define Fouriers theorem and be
able to describe the basics of Fourier analysis
Graphic representation of sound
bull Time domainndash Called a waveformndash Amplitude plotted as
a function of time
bull Frequency domainndash Called a spectrumndash Amplitude spectrumbull amplitude vs frequency
ndash Phase spectrumbull phase vs frequency
ndash May be measured using a variety of ldquowindowrdquo sizes
Same sound different graphs
Time domain
Frequency domain
From Hillenbrand
Classification of sounds
bull Number of frequency componentsndash Simplendash Complex
bull Relationship of frequency componentsndash Periodicndash Aperiodic
bull Durationndash Continuousndash Transient
Simple periodic sound
bull Simple one frequency componentbull Periodic repeating patternbull Completely characterized byndash amplitudendash period (frequency)ndash phase
bull Other names sinusoid simple harmonic motion pure tone
Simple periodic sound Graphic appearance
From Hillenbrand
Complex periodic sounds
bull Complex gt one frequency componentbull Periodic repeating patternbull Continuousbull Frequencies components have a special relation
ndash Lowest frequency fundamental frequencybull Symbol fo
bull Frequency component with longest periodndash Higher frequency components harmonics
bull integer (whole number) multiples of the fo
Complex periodic sounds Graphic appearance
bull Time domainndash repeating pattern of pressure changendash within the cycle things look complex
bull Frequency domain ndash spectral peaks at evenly spaced frequency
bull Complex gt one frequency componentbull Aperiodic Does not repeat itselfbull Frequency components are not systematically
relatedbull May be ndash Continuousndash Transient
Aperiodic sounds Graphic appearance
bull Time domainndash no repeating pattern of pressure change
bull Frequency domainndash the spectrum is dense ndash No ldquopicket fencerdquo
bull Auditory impression sounds lsquonoisyrsquo
Aperiodic sounds Graphic appearance
From Hillenbrand
>
Analysis of complex wavesbull Waves can be summedbull Complex waves are the sum of simple wavesbull Fourier French Mathematician
ndash Any complex waveform may be formed by summing sinusoids of various frequency amplitude and phase
bull Fourier Analysisndash Provides a unique (only one) solution for a given sound signalndash Is reflected in the amplitude and phase spectrum of the signalndash Reveals the building blocks of complex waves which are sinusoids
Learning Objectives
bull Draw and differentiate the waveform and the waveform envelope
bull Draw and differentiate the amplitude spectrum the phase spectrum and the spectrum envelope
bull Differential between short-term spectra and long-term average spectra
The ldquoenveloperdquo of a sound wave
bull Waveform envelopendash imaginary smooth line that follows the peak of the
amplitude of a sound pressure waveformbull Spectrum envelopendash Imaginary smooth line drawn on top of the
amplitude spectrum
Waveform envelope
From Hillenbrand
Waveform envelope
Time
>
Spectrum envelope
Frequency
Ampl
itude
Thought Question
Can an aperiodic and complex periodic sound have identical
spectrum envelopes
Amplitude Spectrum Window Size
bull ldquoshort-termrdquo vs ldquolong-term averagerdquo amplitude spectrum
ldquoInstantaneousrdquo Amplitude Spectra
(Long Term) Average Amplitude Spectrum
Learning Objectivesbull Describe how the amplitude spectrum and the spectrogram are
relatedbull Identify the axis units of the spectrogrambull Provide some advantages of the spectrogram over the
amplitude spectrumbull Distinguish between a wide band and narrow band spectrogram
and outline the different information each providesbull Distinguish between a harmonic and a formant on a
spectrogrambull Be able to draw stylized (highly simplified) spectrograms based
on spectra and spectrum envelopes
The Spectrogram
Rotate90 degrees
F
AF
A
Building a spectrogram
Rotate it so thatThe amplitude isComing out of thepage
F
A This is really narrow because it is a slice in time
F
Time
Building a spectrogram
Dark bands= amplitudePeaks
Time
Freq
uenc
y
Building a spectrogram
Two main types of spectrograms
bull Narrow-band spectrogramsndash Akin to amplitude spectrums ldquolined uprdquondash Frequency resolution is really sharp
bull Wide-band spectrogramsndash Akin to spectrum envelopes ldquolined uprdquondash Frequency resolution not so sharp
Highlights harmonic structure
Highlights spectrum envelope
Wide vs Narrow Band Spectrograms
Learning Objectives
bull Define an acoustic filterbull Draw and label a frequency response curvebull Draw and differentiate different types of acoustic
filtersbull Define terms such as cutoff frequency center
frequency roll off rate gain and bandwidthbull Define and draw a basic filter system and relate that
to the source-filter theory of speech production
What is an ldquoAcousticrdquo Filter
bull holds back (attenuates) certain sounds and lets other sounds through - selective
Why might we be interested in filters
bull Human vocal tract acts like a frequency selective acoustic filter
bull Human auditory system behaves as a frequency selective filter
bull helps us understand how speech is produced and perceived
Kinds of frequency selective filters
Low-pass filtersndash Lets low frequencies ldquopass throughrdquo and attenuates high
frequencies
High-pass filtersndash Lets high frequencies ldquopass throughrdquo and attenuates low
frequencies
Band-pass filtersndash Lets a particular frequency range ldquopass throughrdquo and
attenuates other frequencies
Low Pass Filters
Frequencylow high
Gai
n
+
-
High Pass Filters
Frequencylow high
Gai
n
+
-
Band Pass Filter
Frequencylow high
Gai
n
+
-
Frequency Response Curve (FRC)
Frequencylow high
Gai
n
+
-
Center frequency
lower cutofffrequency
upper cutoff frequency
passband
3 dB
Operation of a filter on a signal
NOTE Amplitude spectrum describes a soundFrequency response curve describes a filter
Learning Objectivesbull Define resonance free and forced vibrationbull Describe how the pendulum and spring mass models can
help explain resonancebull Outline how mass and stiffness influences the resonant
frequency of a mass spring systembull Outline how acoustic resonators behave like acoustic filtersbull Calculate resonant frequencies of a uniform tube based on
its physical dimensionsbull Describe how the wavelength of the sound determines the
resonant frequency of tube
Free vibration
bull objects tend to vibrate at a characteristic or resonant frequency (RF)
Forced vibration
bull A vibrating system can force a nearby system into vibration
bull The efficiency with which this is accomplished is related to the similarity in the resonant frequency (RF) of the two systems
Forced vibration
bull If the RF of the two systems are the same the amplitude of forced vibration will be large
bull If the RF of the two systems are quite different the amplitude of forced vibration will be small or nonexistent
Resonance refers to
bull The tendency for an object to vibrate at a particular frequency or frequencies
bull The ability of a vibrating system to force another system into vibration
Back to the mass spring model
bull Vibratory frequency of the mass spring determined byndash Massndash Stiffness of the spring
httpphetcoloradoeduensimulationmass-spring-lab
Acoustic Resonance
bull Ideas from mechanical resonance also applies to acoustic systems
bull Acoustic chambers will transmit sound frequencies with more or less efficiency depending upon the physical characteristics
bull Therefore they act as filters passing through (and even amplifying) some frequencies and attentuating others
Acoustic Resonance
bull And since they act as filters they have most of the same features of a filter even though we might use different names
bull Center frequency is often termed the resonant frequency
bull Frequency response curve often termed the resonance curve
Helmholtz Resonator
Actions of a Helmholtz Resonator
Stephen M Tasko
Other Acoustic Resonators Tube Resonators
bull Uniform tubes Factors that influence resonancendash Lengthndash Cross-sectional area along its lengthndash Whether it is closed at either or both ends
Uniform tube closed at one end
Uniform tube closed at one end
Stephen M Tasko
Uniform tube closed at one end
First resonance or formant
F1 = c4lWhere
c=speed of sound (35000 cmsec)l = length of the tube
males ~ 175 cmfemales ~ 14 cm
Higher resonantformant frequencies are odd multiples of F1
For examplebull F1 = (c4l )1
bull F2 = (c4l )3
bull F3 = (c4l )5
Comparing Helmholtz and tube resonators
Resonator Features
Sharply tuned Broadly tuned
Resonator Features
An example of the resonance characteristics of the human vocal tract
Frequency
Gain
SPPA 4030 Speech Science
Topic 1 The Speech Chain
The Speech Chain (Denes amp Pinson 1993)
What information is embedded in the speech signal
Branches of science employed to understand speech communication
Physical Quantities Review An Independent Learning Activity
Assignment 1
Topic 2 The Source-Filter Theory of Speech Production An Intr
Producing Speech
Source-Filter Theory of Speech Production
Vocal tract is a tube that can vary its shape
Source Filter Theory
Same Source Different Filter
Different Source Same Filters
Different Source Same Filters (Human)
Different Source Same Filters (Human) (2)
Different Source Same Filters (Human) (3)
Different Source Same Filters (Human) (4)
Different Source Same Filters (Non-Human)
Different Source Same Filters (Non-Human) (2)
Different Source Same Filters (Non-Human) If it quacks like a
Source Filter Theory Applied Alaryngeal Speech
Source-Filter Theory Applied Esophageal Insufflation Test
Source-Filter Theory Applied Tracheoesophageal (TE) Speech
Source Filter Theory Applied The Talkbox
Source-Filter Theory Applied The Talkbox
Topic 3 A Brief Review of Physical Acoustics
Spring Mass Model
What is sound
Sound-conducting media
Model of air molecule vibration (Time 1)
Model of air molecule vibration (Time 2)
Model of air molecule vibration (Time 3)
Model of air molecule vibration (Time 4)
Model of air molecule vibration (Time 5)
Model of air molecule vibration
Wave action of molecular motion
Amplitude waveform
Amplitude waveform (2)
Where is pressure in this model
Pressure waveform
Measuring Sound
Measuring Sound Signal Amplitude
Measuring Sound Signal Amplitude (2)
What units do we use to measure signal amplitude
Brief Review The decibel scale
Absolute vs relative measurement
Typical reference values
Howeverhellip
Linear vs logarithmic
Linear vs logarithmic (2)
Logarithmic Scale
Logarithmic Scale (2)
Combining the idea of logarithmic and relativehellip
Intensity vs Pressure
Extending the formula to pressure
Measuring Sound Frequencyperiod
Measuring Sound Frequencyperiod (2)
Phase Uniform Circular Motion
Initiating a sound waves that differ only in phase
Spatial variation in pressure wave
Spatial variation in pressure wave
Spatial variation in pressure wave (2)
Relation between frequency and wavelength
Learning Objectives
Graphic representation of sound
Same sound different graphs
Classification of sounds
Simple periodic sound
Simple periodic sound Graphic appearance
Complex periodic sounds
Complex periodic sounds Graphic appearance
Complex periodic sounds Graphic appearance (2)
Glottal Source
Amplitude vs Phase Spectrum
Amplitude vs Phase Spectrum (2)
(Complex) Aperiodic sounds
Aperiodic sounds Graphic appearance
Aperiodic sounds Graphic appearance (2)
Analysis of complex waves
Learning Objectives (2)
The ldquoenveloperdquo of a sound wave
Waveform envelope
Waveform envelope (2)
Spectrum envelope
Thought Question
Amplitude Spectrum Window Size
ldquoInstantaneousrdquo Amplitude Spectra
(Long Term) Average Amplitude Spectrum
Slide 90
Learning Objectives (3)
The Spectrogram
Building a spectrogram
Building a spectrogram
Building a spectrogram (2)
Two main types of spectrograms
Wide vs Narrow Band Spectrograms
Learning Objectives (4)
What is an ldquoAcousticrdquo Filter
Why might we be interested in filters
Kinds of frequency selective filters
Low Pass Filters
High Pass Filters
Band Pass Filter
Frequency Response Curve (FRC)
Operation of a filter on a signal
Learning Objectives (5)
Free vibration
Forced vibration
Forced vibration (2)
Resonance refers to
Back to the mass spring model
Acoustic Resonance
Acoustic Resonance (2)
Helmholtz Resonator
Actions of a Helmholtz Resonator
Other Acoustic Resonators Tube Resonators
Uniform tube closed at one end
Uniform tube closed at one end (2)
Uniform tube closed at one end
Comparing Helmholtz and tube resonators
Slide 122
Slide 123
Learning Objectivesbull Draw and describe time-domain and frequency-domain
representation of soundbull Distinguish between simple and complex sound sounds with
regard to physical characteristics and graphical representations
bull Distinguish between periodic and aperiodic sounds with specific emphasis on terms such as fundamental frequencyperiod harmonics and overtones
bull Distinguish between continuous and transient sounds bull Describe how waves sum define Fouriers theorem and be
able to describe the basics of Fourier analysis
Graphic representation of sound
bull Time domainndash Called a waveformndash Amplitude plotted as
a function of time
bull Frequency domainndash Called a spectrumndash Amplitude spectrumbull amplitude vs frequency
ndash Phase spectrumbull phase vs frequency
ndash May be measured using a variety of ldquowindowrdquo sizes
Same sound different graphs
Time domain
Frequency domain
From Hillenbrand
Classification of sounds
bull Number of frequency componentsndash Simplendash Complex
bull Relationship of frequency componentsndash Periodicndash Aperiodic
bull Durationndash Continuousndash Transient
Simple periodic sound
bull Simple one frequency componentbull Periodic repeating patternbull Completely characterized byndash amplitudendash period (frequency)ndash phase
bull Other names sinusoid simple harmonic motion pure tone
Simple periodic sound Graphic appearance
From Hillenbrand
Complex periodic sounds
bull Complex gt one frequency componentbull Periodic repeating patternbull Continuousbull Frequencies components have a special relation
ndash Lowest frequency fundamental frequencybull Symbol fo
bull Frequency component with longest periodndash Higher frequency components harmonics
bull integer (whole number) multiples of the fo
Complex periodic sounds Graphic appearance
bull Time domainndash repeating pattern of pressure changendash within the cycle things look complex
bull Frequency domain ndash spectral peaks at evenly spaced frequency
bull Complex gt one frequency componentbull Aperiodic Does not repeat itselfbull Frequency components are not systematically
relatedbull May be ndash Continuousndash Transient
Aperiodic sounds Graphic appearance
bull Time domainndash no repeating pattern of pressure change
bull Frequency domainndash the spectrum is dense ndash No ldquopicket fencerdquo
bull Auditory impression sounds lsquonoisyrsquo
Aperiodic sounds Graphic appearance
From Hillenbrand
>
Analysis of complex wavesbull Waves can be summedbull Complex waves are the sum of simple wavesbull Fourier French Mathematician
ndash Any complex waveform may be formed by summing sinusoids of various frequency amplitude and phase
bull Fourier Analysisndash Provides a unique (only one) solution for a given sound signalndash Is reflected in the amplitude and phase spectrum of the signalndash Reveals the building blocks of complex waves which are sinusoids
Learning Objectives
bull Draw and differentiate the waveform and the waveform envelope
bull Draw and differentiate the amplitude spectrum the phase spectrum and the spectrum envelope
bull Differential between short-term spectra and long-term average spectra
The ldquoenveloperdquo of a sound wave
bull Waveform envelopendash imaginary smooth line that follows the peak of the
amplitude of a sound pressure waveformbull Spectrum envelopendash Imaginary smooth line drawn on top of the
amplitude spectrum
Waveform envelope
From Hillenbrand
Waveform envelope
Time
>
Spectrum envelope
Frequency
Ampl
itude
Thought Question
Can an aperiodic and complex periodic sound have identical
spectrum envelopes
Amplitude Spectrum Window Size
bull ldquoshort-termrdquo vs ldquolong-term averagerdquo amplitude spectrum
ldquoInstantaneousrdquo Amplitude Spectra
(Long Term) Average Amplitude Spectrum
Learning Objectivesbull Describe how the amplitude spectrum and the spectrogram are
relatedbull Identify the axis units of the spectrogrambull Provide some advantages of the spectrogram over the
amplitude spectrumbull Distinguish between a wide band and narrow band spectrogram
and outline the different information each providesbull Distinguish between a harmonic and a formant on a
spectrogrambull Be able to draw stylized (highly simplified) spectrograms based
on spectra and spectrum envelopes
The Spectrogram
Rotate90 degrees
F
AF
A
Building a spectrogram
Rotate it so thatThe amplitude isComing out of thepage
F
A This is really narrow because it is a slice in time
F
Time
Building a spectrogram
Dark bands= amplitudePeaks
Time
Freq
uenc
y
Building a spectrogram
Two main types of spectrograms
bull Narrow-band spectrogramsndash Akin to amplitude spectrums ldquolined uprdquondash Frequency resolution is really sharp
bull Wide-band spectrogramsndash Akin to spectrum envelopes ldquolined uprdquondash Frequency resolution not so sharp
Highlights harmonic structure
Highlights spectrum envelope
Wide vs Narrow Band Spectrograms
Learning Objectives
bull Define an acoustic filterbull Draw and label a frequency response curvebull Draw and differentiate different types of acoustic
filtersbull Define terms such as cutoff frequency center
frequency roll off rate gain and bandwidthbull Define and draw a basic filter system and relate that
to the source-filter theory of speech production
What is an ldquoAcousticrdquo Filter
bull holds back (attenuates) certain sounds and lets other sounds through - selective
Why might we be interested in filters
bull Human vocal tract acts like a frequency selective acoustic filter
bull Human auditory system behaves as a frequency selective filter
bull helps us understand how speech is produced and perceived
Kinds of frequency selective filters
Low-pass filtersndash Lets low frequencies ldquopass throughrdquo and attenuates high
frequencies
High-pass filtersndash Lets high frequencies ldquopass throughrdquo and attenuates low
frequencies
Band-pass filtersndash Lets a particular frequency range ldquopass throughrdquo and
attenuates other frequencies
Low Pass Filters
Frequencylow high
Gai
n
+
-
High Pass Filters
Frequencylow high
Gai
n
+
-
Band Pass Filter
Frequencylow high
Gai
n
+
-
Frequency Response Curve (FRC)
Frequencylow high
Gai
n
+
-
Center frequency
lower cutofffrequency
upper cutoff frequency
passband
3 dB
Operation of a filter on a signal
NOTE Amplitude spectrum describes a soundFrequency response curve describes a filter
Learning Objectivesbull Define resonance free and forced vibrationbull Describe how the pendulum and spring mass models can
help explain resonancebull Outline how mass and stiffness influences the resonant
frequency of a mass spring systembull Outline how acoustic resonators behave like acoustic filtersbull Calculate resonant frequencies of a uniform tube based on
its physical dimensionsbull Describe how the wavelength of the sound determines the
resonant frequency of tube
Free vibration
bull objects tend to vibrate at a characteristic or resonant frequency (RF)
Forced vibration
bull A vibrating system can force a nearby system into vibration
bull The efficiency with which this is accomplished is related to the similarity in the resonant frequency (RF) of the two systems
Forced vibration
bull If the RF of the two systems are the same the amplitude of forced vibration will be large
bull If the RF of the two systems are quite different the amplitude of forced vibration will be small or nonexistent
Resonance refers to
bull The tendency for an object to vibrate at a particular frequency or frequencies
bull The ability of a vibrating system to force another system into vibration
Back to the mass spring model
bull Vibratory frequency of the mass spring determined byndash Massndash Stiffness of the spring
httpphetcoloradoeduensimulationmass-spring-lab
Acoustic Resonance
bull Ideas from mechanical resonance also applies to acoustic systems
bull Acoustic chambers will transmit sound frequencies with more or less efficiency depending upon the physical characteristics
bull Therefore they act as filters passing through (and even amplifying) some frequencies and attentuating others
Acoustic Resonance
bull And since they act as filters they have most of the same features of a filter even though we might use different names
bull Center frequency is often termed the resonant frequency
bull Frequency response curve often termed the resonance curve
Helmholtz Resonator
Actions of a Helmholtz Resonator
Stephen M Tasko
Other Acoustic Resonators Tube Resonators
bull Uniform tubes Factors that influence resonancendash Lengthndash Cross-sectional area along its lengthndash Whether it is closed at either or both ends
Uniform tube closed at one end
Uniform tube closed at one end
Stephen M Tasko
Uniform tube closed at one end
First resonance or formant
F1 = c4lWhere
c=speed of sound (35000 cmsec)l = length of the tube
males ~ 175 cmfemales ~ 14 cm
Higher resonantformant frequencies are odd multiples of F1
For examplebull F1 = (c4l )1
bull F2 = (c4l )3
bull F3 = (c4l )5
Comparing Helmholtz and tube resonators
Resonator Features
Sharply tuned Broadly tuned
Resonator Features
An example of the resonance characteristics of the human vocal tract
Frequency
Gain
SPPA 4030 Speech Science
Topic 1 The Speech Chain
The Speech Chain (Denes amp Pinson 1993)
What information is embedded in the speech signal
Branches of science employed to understand speech communication
Physical Quantities Review An Independent Learning Activity
Assignment 1
Topic 2 The Source-Filter Theory of Speech Production An Intr
Producing Speech
Source-Filter Theory of Speech Production
Vocal tract is a tube that can vary its shape
Source Filter Theory
Same Source Different Filter
Different Source Same Filters
Different Source Same Filters (Human)
Different Source Same Filters (Human) (2)
Different Source Same Filters (Human) (3)
Different Source Same Filters (Human) (4)
Different Source Same Filters (Non-Human)
Different Source Same Filters (Non-Human) (2)
Different Source Same Filters (Non-Human) If it quacks like a
Source Filter Theory Applied Alaryngeal Speech
Source-Filter Theory Applied Esophageal Insufflation Test
Source-Filter Theory Applied Tracheoesophageal (TE) Speech
Source Filter Theory Applied The Talkbox
Source-Filter Theory Applied The Talkbox
Topic 3 A Brief Review of Physical Acoustics
Spring Mass Model
What is sound
Sound-conducting media
Model of air molecule vibration (Time 1)
Model of air molecule vibration (Time 2)
Model of air molecule vibration (Time 3)
Model of air molecule vibration (Time 4)
Model of air molecule vibration (Time 5)
Model of air molecule vibration
Wave action of molecular motion
Amplitude waveform
Amplitude waveform (2)
Where is pressure in this model
Pressure waveform
Measuring Sound
Measuring Sound Signal Amplitude
Measuring Sound Signal Amplitude (2)
What units do we use to measure signal amplitude
Brief Review The decibel scale
Absolute vs relative measurement
Typical reference values
Howeverhellip
Linear vs logarithmic
Linear vs logarithmic (2)
Logarithmic Scale
Logarithmic Scale (2)
Combining the idea of logarithmic and relativehellip
Intensity vs Pressure
Extending the formula to pressure
Measuring Sound Frequencyperiod
Measuring Sound Frequencyperiod (2)
Phase Uniform Circular Motion
Initiating a sound waves that differ only in phase
Spatial variation in pressure wave
Spatial variation in pressure wave
Spatial variation in pressure wave (2)
Relation between frequency and wavelength
Learning Objectives
Graphic representation of sound
Same sound different graphs
Classification of sounds
Simple periodic sound
Simple periodic sound Graphic appearance
Complex periodic sounds
Complex periodic sounds Graphic appearance
Complex periodic sounds Graphic appearance (2)
Glottal Source
Amplitude vs Phase Spectrum
Amplitude vs Phase Spectrum (2)
(Complex) Aperiodic sounds
Aperiodic sounds Graphic appearance
Aperiodic sounds Graphic appearance (2)
Analysis of complex waves
Learning Objectives (2)
The ldquoenveloperdquo of a sound wave
Waveform envelope
Waveform envelope (2)
Spectrum envelope
Thought Question
Amplitude Spectrum Window Size
ldquoInstantaneousrdquo Amplitude Spectra
(Long Term) Average Amplitude Spectrum
Slide 90
Learning Objectives (3)
The Spectrogram
Building a spectrogram
Building a spectrogram
Building a spectrogram (2)
Two main types of spectrograms
Wide vs Narrow Band Spectrograms
Learning Objectives (4)
What is an ldquoAcousticrdquo Filter
Why might we be interested in filters
Kinds of frequency selective filters
Low Pass Filters
High Pass Filters
Band Pass Filter
Frequency Response Curve (FRC)
Operation of a filter on a signal
Learning Objectives (5)
Free vibration
Forced vibration
Forced vibration (2)
Resonance refers to
Back to the mass spring model
Acoustic Resonance
Acoustic Resonance (2)
Helmholtz Resonator
Actions of a Helmholtz Resonator
Other Acoustic Resonators Tube Resonators
Uniform tube closed at one end
Uniform tube closed at one end (2)
Uniform tube closed at one end
Comparing Helmholtz and tube resonators
Slide 122
Slide 123
Graphic representation of sound
bull Time domainndash Called a waveformndash Amplitude plotted as
a function of time
bull Frequency domainndash Called a spectrumndash Amplitude spectrumbull amplitude vs frequency
ndash Phase spectrumbull phase vs frequency
ndash May be measured using a variety of ldquowindowrdquo sizes
Same sound different graphs
Time domain
Frequency domain
From Hillenbrand
Classification of sounds
bull Number of frequency componentsndash Simplendash Complex
bull Relationship of frequency componentsndash Periodicndash Aperiodic
bull Durationndash Continuousndash Transient
Simple periodic sound
bull Simple one frequency componentbull Periodic repeating patternbull Completely characterized byndash amplitudendash period (frequency)ndash phase
bull Other names sinusoid simple harmonic motion pure tone
Simple periodic sound Graphic appearance
From Hillenbrand
Complex periodic sounds
bull Complex gt one frequency componentbull Periodic repeating patternbull Continuousbull Frequencies components have a special relation
ndash Lowest frequency fundamental frequencybull Symbol fo
bull Frequency component with longest periodndash Higher frequency components harmonics
bull integer (whole number) multiples of the fo
Complex periodic sounds Graphic appearance
bull Time domainndash repeating pattern of pressure changendash within the cycle things look complex
bull Frequency domain ndash spectral peaks at evenly spaced frequency
bull Complex gt one frequency componentbull Aperiodic Does not repeat itselfbull Frequency components are not systematically
relatedbull May be ndash Continuousndash Transient
Aperiodic sounds Graphic appearance
bull Time domainndash no repeating pattern of pressure change
bull Frequency domainndash the spectrum is dense ndash No ldquopicket fencerdquo
bull Auditory impression sounds lsquonoisyrsquo
Aperiodic sounds Graphic appearance
From Hillenbrand
>
Analysis of complex wavesbull Waves can be summedbull Complex waves are the sum of simple wavesbull Fourier French Mathematician
ndash Any complex waveform may be formed by summing sinusoids of various frequency amplitude and phase
bull Fourier Analysisndash Provides a unique (only one) solution for a given sound signalndash Is reflected in the amplitude and phase spectrum of the signalndash Reveals the building blocks of complex waves which are sinusoids
Learning Objectives
bull Draw and differentiate the waveform and the waveform envelope
bull Draw and differentiate the amplitude spectrum the phase spectrum and the spectrum envelope
bull Differential between short-term spectra and long-term average spectra
The ldquoenveloperdquo of a sound wave
bull Waveform envelopendash imaginary smooth line that follows the peak of the
amplitude of a sound pressure waveformbull Spectrum envelopendash Imaginary smooth line drawn on top of the
amplitude spectrum
Waveform envelope
From Hillenbrand
Waveform envelope
Time
>
Spectrum envelope
Frequency
Ampl
itude
Thought Question
Can an aperiodic and complex periodic sound have identical
spectrum envelopes
Amplitude Spectrum Window Size
bull ldquoshort-termrdquo vs ldquolong-term averagerdquo amplitude spectrum
ldquoInstantaneousrdquo Amplitude Spectra
(Long Term) Average Amplitude Spectrum
Learning Objectivesbull Describe how the amplitude spectrum and the spectrogram are
relatedbull Identify the axis units of the spectrogrambull Provide some advantages of the spectrogram over the
amplitude spectrumbull Distinguish between a wide band and narrow band spectrogram
and outline the different information each providesbull Distinguish between a harmonic and a formant on a
spectrogrambull Be able to draw stylized (highly simplified) spectrograms based
on spectra and spectrum envelopes
The Spectrogram
Rotate90 degrees
F
AF
A
Building a spectrogram
Rotate it so thatThe amplitude isComing out of thepage
F
A This is really narrow because it is a slice in time
F
Time
Building a spectrogram
Dark bands= amplitudePeaks
Time
Freq
uenc
y
Building a spectrogram
Two main types of spectrograms
bull Narrow-band spectrogramsndash Akin to amplitude spectrums ldquolined uprdquondash Frequency resolution is really sharp
bull Wide-band spectrogramsndash Akin to spectrum envelopes ldquolined uprdquondash Frequency resolution not so sharp
Highlights harmonic structure
Highlights spectrum envelope
Wide vs Narrow Band Spectrograms
Learning Objectives
bull Define an acoustic filterbull Draw and label a frequency response curvebull Draw and differentiate different types of acoustic
filtersbull Define terms such as cutoff frequency center
frequency roll off rate gain and bandwidthbull Define and draw a basic filter system and relate that
to the source-filter theory of speech production
What is an ldquoAcousticrdquo Filter
bull holds back (attenuates) certain sounds and lets other sounds through - selective
Why might we be interested in filters
bull Human vocal tract acts like a frequency selective acoustic filter
bull Human auditory system behaves as a frequency selective filter
bull helps us understand how speech is produced and perceived
Kinds of frequency selective filters
Low-pass filtersndash Lets low frequencies ldquopass throughrdquo and attenuates high
frequencies
High-pass filtersndash Lets high frequencies ldquopass throughrdquo and attenuates low
frequencies
Band-pass filtersndash Lets a particular frequency range ldquopass throughrdquo and
attenuates other frequencies
Low Pass Filters
Frequencylow high
Gai
n
+
-
High Pass Filters
Frequencylow high
Gai
n
+
-
Band Pass Filter
Frequencylow high
Gai
n
+
-
Frequency Response Curve (FRC)
Frequencylow high
Gai
n
+
-
Center frequency
lower cutofffrequency
upper cutoff frequency
passband
3 dB
Operation of a filter on a signal
NOTE Amplitude spectrum describes a soundFrequency response curve describes a filter
Learning Objectivesbull Define resonance free and forced vibrationbull Describe how the pendulum and spring mass models can
help explain resonancebull Outline how mass and stiffness influences the resonant
frequency of a mass spring systembull Outline how acoustic resonators behave like acoustic filtersbull Calculate resonant frequencies of a uniform tube based on
its physical dimensionsbull Describe how the wavelength of the sound determines the
resonant frequency of tube
Free vibration
bull objects tend to vibrate at a characteristic or resonant frequency (RF)
Forced vibration
bull A vibrating system can force a nearby system into vibration
bull The efficiency with which this is accomplished is related to the similarity in the resonant frequency (RF) of the two systems
Forced vibration
bull If the RF of the two systems are the same the amplitude of forced vibration will be large
bull If the RF of the two systems are quite different the amplitude of forced vibration will be small or nonexistent
Resonance refers to
bull The tendency for an object to vibrate at a particular frequency or frequencies
bull The ability of a vibrating system to force another system into vibration
Back to the mass spring model
bull Vibratory frequency of the mass spring determined byndash Massndash Stiffness of the spring
httpphetcoloradoeduensimulationmass-spring-lab
Acoustic Resonance
bull Ideas from mechanical resonance also applies to acoustic systems
bull Acoustic chambers will transmit sound frequencies with more or less efficiency depending upon the physical characteristics
bull Therefore they act as filters passing through (and even amplifying) some frequencies and attentuating others
Acoustic Resonance
bull And since they act as filters they have most of the same features of a filter even though we might use different names
bull Center frequency is often termed the resonant frequency
bull Frequency response curve often termed the resonance curve
Helmholtz Resonator
Actions of a Helmholtz Resonator
Stephen M Tasko
Other Acoustic Resonators Tube Resonators
bull Uniform tubes Factors that influence resonancendash Lengthndash Cross-sectional area along its lengthndash Whether it is closed at either or both ends
Uniform tube closed at one end
Uniform tube closed at one end
Stephen M Tasko
Uniform tube closed at one end
First resonance or formant
F1 = c4lWhere
c=speed of sound (35000 cmsec)l = length of the tube
males ~ 175 cmfemales ~ 14 cm
Higher resonantformant frequencies are odd multiples of F1
For examplebull F1 = (c4l )1
bull F2 = (c4l )3
bull F3 = (c4l )5
Comparing Helmholtz and tube resonators
Resonator Features
Sharply tuned Broadly tuned
Resonator Features
An example of the resonance characteristics of the human vocal tract
Frequency
Gain
SPPA 4030 Speech Science
Topic 1 The Speech Chain
The Speech Chain (Denes amp Pinson 1993)
What information is embedded in the speech signal
Branches of science employed to understand speech communication
Physical Quantities Review An Independent Learning Activity
Assignment 1
Topic 2 The Source-Filter Theory of Speech Production An Intr
Producing Speech
Source-Filter Theory of Speech Production
Vocal tract is a tube that can vary its shape
Source Filter Theory
Same Source Different Filter
Different Source Same Filters
Different Source Same Filters (Human)
Different Source Same Filters (Human) (2)
Different Source Same Filters (Human) (3)
Different Source Same Filters (Human) (4)
Different Source Same Filters (Non-Human)
Different Source Same Filters (Non-Human) (2)
Different Source Same Filters (Non-Human) If it quacks like a
Source Filter Theory Applied Alaryngeal Speech
Source-Filter Theory Applied Esophageal Insufflation Test
Source-Filter Theory Applied Tracheoesophageal (TE) Speech
Source Filter Theory Applied The Talkbox
Source-Filter Theory Applied The Talkbox
Topic 3 A Brief Review of Physical Acoustics
Spring Mass Model
What is sound
Sound-conducting media
Model of air molecule vibration (Time 1)
Model of air molecule vibration (Time 2)
Model of air molecule vibration (Time 3)
Model of air molecule vibration (Time 4)
Model of air molecule vibration (Time 5)
Model of air molecule vibration
Wave action of molecular motion
Amplitude waveform
Amplitude waveform (2)
Where is pressure in this model
Pressure waveform
Measuring Sound
Measuring Sound Signal Amplitude
Measuring Sound Signal Amplitude (2)
What units do we use to measure signal amplitude
Brief Review The decibel scale
Absolute vs relative measurement
Typical reference values
Howeverhellip
Linear vs logarithmic
Linear vs logarithmic (2)
Logarithmic Scale
Logarithmic Scale (2)
Combining the idea of logarithmic and relativehellip
Intensity vs Pressure
Extending the formula to pressure
Measuring Sound Frequencyperiod
Measuring Sound Frequencyperiod (2)
Phase Uniform Circular Motion
Initiating a sound waves that differ only in phase
Spatial variation in pressure wave
Spatial variation in pressure wave
Spatial variation in pressure wave (2)
Relation between frequency and wavelength
Learning Objectives
Graphic representation of sound
Same sound different graphs
Classification of sounds
Simple periodic sound
Simple periodic sound Graphic appearance
Complex periodic sounds
Complex periodic sounds Graphic appearance
Complex periodic sounds Graphic appearance (2)
Glottal Source
Amplitude vs Phase Spectrum
Amplitude vs Phase Spectrum (2)
(Complex) Aperiodic sounds
Aperiodic sounds Graphic appearance
Aperiodic sounds Graphic appearance (2)
Analysis of complex waves
Learning Objectives (2)
The ldquoenveloperdquo of a sound wave
Waveform envelope
Waveform envelope (2)
Spectrum envelope
Thought Question
Amplitude Spectrum Window Size
ldquoInstantaneousrdquo Amplitude Spectra
(Long Term) Average Amplitude Spectrum
Slide 90
Learning Objectives (3)
The Spectrogram
Building a spectrogram
Building a spectrogram
Building a spectrogram (2)
Two main types of spectrograms
Wide vs Narrow Band Spectrograms
Learning Objectives (4)
What is an ldquoAcousticrdquo Filter
Why might we be interested in filters
Kinds of frequency selective filters
Low Pass Filters
High Pass Filters
Band Pass Filter
Frequency Response Curve (FRC)
Operation of a filter on a signal
Learning Objectives (5)
Free vibration
Forced vibration
Forced vibration (2)
Resonance refers to
Back to the mass spring model
Acoustic Resonance
Acoustic Resonance (2)
Helmholtz Resonator
Actions of a Helmholtz Resonator
Other Acoustic Resonators Tube Resonators
Uniform tube closed at one end
Uniform tube closed at one end (2)
Uniform tube closed at one end
Comparing Helmholtz and tube resonators
Slide 122
Slide 123
Same sound different graphs
Time domain
Frequency domain
From Hillenbrand
Classification of sounds
bull Number of frequency componentsndash Simplendash Complex
bull Relationship of frequency componentsndash Periodicndash Aperiodic
bull Durationndash Continuousndash Transient
Simple periodic sound
bull Simple one frequency componentbull Periodic repeating patternbull Completely characterized byndash amplitudendash period (frequency)ndash phase
bull Other names sinusoid simple harmonic motion pure tone
Simple periodic sound Graphic appearance
From Hillenbrand
Complex periodic sounds
bull Complex gt one frequency componentbull Periodic repeating patternbull Continuousbull Frequencies components have a special relation
ndash Lowest frequency fundamental frequencybull Symbol fo
bull Frequency component with longest periodndash Higher frequency components harmonics
bull integer (whole number) multiples of the fo
Complex periodic sounds Graphic appearance
bull Time domainndash repeating pattern of pressure changendash within the cycle things look complex
bull Frequency domain ndash spectral peaks at evenly spaced frequency
bull Complex gt one frequency componentbull Aperiodic Does not repeat itselfbull Frequency components are not systematically
relatedbull May be ndash Continuousndash Transient
Aperiodic sounds Graphic appearance
bull Time domainndash no repeating pattern of pressure change
bull Frequency domainndash the spectrum is dense ndash No ldquopicket fencerdquo
bull Auditory impression sounds lsquonoisyrsquo
Aperiodic sounds Graphic appearance
From Hillenbrand
>
Analysis of complex wavesbull Waves can be summedbull Complex waves are the sum of simple wavesbull Fourier French Mathematician
ndash Any complex waveform may be formed by summing sinusoids of various frequency amplitude and phase
bull Fourier Analysisndash Provides a unique (only one) solution for a given sound signalndash Is reflected in the amplitude and phase spectrum of the signalndash Reveals the building blocks of complex waves which are sinusoids
Learning Objectives
bull Draw and differentiate the waveform and the waveform envelope
bull Draw and differentiate the amplitude spectrum the phase spectrum and the spectrum envelope
bull Differential between short-term spectra and long-term average spectra
The ldquoenveloperdquo of a sound wave
bull Waveform envelopendash imaginary smooth line that follows the peak of the
amplitude of a sound pressure waveformbull Spectrum envelopendash Imaginary smooth line drawn on top of the
amplitude spectrum
Waveform envelope
From Hillenbrand
Waveform envelope
Time
>
Spectrum envelope
Frequency
Ampl
itude
Thought Question
Can an aperiodic and complex periodic sound have identical
spectrum envelopes
Amplitude Spectrum Window Size
bull ldquoshort-termrdquo vs ldquolong-term averagerdquo amplitude spectrum
ldquoInstantaneousrdquo Amplitude Spectra
(Long Term) Average Amplitude Spectrum
Learning Objectivesbull Describe how the amplitude spectrum and the spectrogram are
relatedbull Identify the axis units of the spectrogrambull Provide some advantages of the spectrogram over the
amplitude spectrumbull Distinguish between a wide band and narrow band spectrogram
and outline the different information each providesbull Distinguish between a harmonic and a formant on a
spectrogrambull Be able to draw stylized (highly simplified) spectrograms based
on spectra and spectrum envelopes
The Spectrogram
Rotate90 degrees
F
AF
A
Building a spectrogram
Rotate it so thatThe amplitude isComing out of thepage
F
A This is really narrow because it is a slice in time
F
Time
Building a spectrogram
Dark bands= amplitudePeaks
Time
Freq
uenc
y
Building a spectrogram
Two main types of spectrograms
bull Narrow-band spectrogramsndash Akin to amplitude spectrums ldquolined uprdquondash Frequency resolution is really sharp
bull Wide-band spectrogramsndash Akin to spectrum envelopes ldquolined uprdquondash Frequency resolution not so sharp
Highlights harmonic structure
Highlights spectrum envelope
Wide vs Narrow Band Spectrograms
Learning Objectives
bull Define an acoustic filterbull Draw and label a frequency response curvebull Draw and differentiate different types of acoustic
filtersbull Define terms such as cutoff frequency center
frequency roll off rate gain and bandwidthbull Define and draw a basic filter system and relate that
to the source-filter theory of speech production
What is an ldquoAcousticrdquo Filter
bull holds back (attenuates) certain sounds and lets other sounds through - selective
Why might we be interested in filters
bull Human vocal tract acts like a frequency selective acoustic filter
bull Human auditory system behaves as a frequency selective filter
bull helps us understand how speech is produced and perceived
Kinds of frequency selective filters
Low-pass filtersndash Lets low frequencies ldquopass throughrdquo and attenuates high
frequencies
High-pass filtersndash Lets high frequencies ldquopass throughrdquo and attenuates low
frequencies
Band-pass filtersndash Lets a particular frequency range ldquopass throughrdquo and
attenuates other frequencies
Low Pass Filters
Frequencylow high
Gai
n
+
-
High Pass Filters
Frequencylow high
Gai
n
+
-
Band Pass Filter
Frequencylow high
Gai
n
+
-
Frequency Response Curve (FRC)
Frequencylow high
Gai
n
+
-
Center frequency
lower cutofffrequency
upper cutoff frequency
passband
3 dB
Operation of a filter on a signal
NOTE Amplitude spectrum describes a soundFrequency response curve describes a filter
Learning Objectivesbull Define resonance free and forced vibrationbull Describe how the pendulum and spring mass models can
help explain resonancebull Outline how mass and stiffness influences the resonant
frequency of a mass spring systembull Outline how acoustic resonators behave like acoustic filtersbull Calculate resonant frequencies of a uniform tube based on
its physical dimensionsbull Describe how the wavelength of the sound determines the
resonant frequency of tube
Free vibration
bull objects tend to vibrate at a characteristic or resonant frequency (RF)
Forced vibration
bull A vibrating system can force a nearby system into vibration
bull The efficiency with which this is accomplished is related to the similarity in the resonant frequency (RF) of the two systems
Forced vibration
bull If the RF of the two systems are the same the amplitude of forced vibration will be large
bull If the RF of the two systems are quite different the amplitude of forced vibration will be small or nonexistent
Resonance refers to
bull The tendency for an object to vibrate at a particular frequency or frequencies
bull The ability of a vibrating system to force another system into vibration
Back to the mass spring model
bull Vibratory frequency of the mass spring determined byndash Massndash Stiffness of the spring
httpphetcoloradoeduensimulationmass-spring-lab
Acoustic Resonance
bull Ideas from mechanical resonance also applies to acoustic systems
bull Acoustic chambers will transmit sound frequencies with more or less efficiency depending upon the physical characteristics
bull Therefore they act as filters passing through (and even amplifying) some frequencies and attentuating others
Acoustic Resonance
bull And since they act as filters they have most of the same features of a filter even though we might use different names
bull Center frequency is often termed the resonant frequency
bull Frequency response curve often termed the resonance curve
Helmholtz Resonator
Actions of a Helmholtz Resonator
Stephen M Tasko
Other Acoustic Resonators Tube Resonators
bull Uniform tubes Factors that influence resonancendash Lengthndash Cross-sectional area along its lengthndash Whether it is closed at either or both ends
Uniform tube closed at one end
Uniform tube closed at one end
Stephen M Tasko
Uniform tube closed at one end
First resonance or formant
F1 = c4lWhere
c=speed of sound (35000 cmsec)l = length of the tube
males ~ 175 cmfemales ~ 14 cm
Higher resonantformant frequencies are odd multiples of F1
For examplebull F1 = (c4l )1
bull F2 = (c4l )3
bull F3 = (c4l )5
Comparing Helmholtz and tube resonators
Resonator Features
Sharply tuned Broadly tuned
Resonator Features
An example of the resonance characteristics of the human vocal tract
Frequency
Gain
SPPA 4030 Speech Science
Topic 1 The Speech Chain
The Speech Chain (Denes amp Pinson 1993)
What information is embedded in the speech signal
Branches of science employed to understand speech communication
Physical Quantities Review An Independent Learning Activity
Assignment 1
Topic 2 The Source-Filter Theory of Speech Production An Intr
Producing Speech
Source-Filter Theory of Speech Production
Vocal tract is a tube that can vary its shape
Source Filter Theory
Same Source Different Filter
Different Source Same Filters
Different Source Same Filters (Human)
Different Source Same Filters (Human) (2)
Different Source Same Filters (Human) (3)
Different Source Same Filters (Human) (4)
Different Source Same Filters (Non-Human)
Different Source Same Filters (Non-Human) (2)
Different Source Same Filters (Non-Human) If it quacks like a
Source Filter Theory Applied Alaryngeal Speech
Source-Filter Theory Applied Esophageal Insufflation Test
Source-Filter Theory Applied Tracheoesophageal (TE) Speech
Source Filter Theory Applied The Talkbox
Source-Filter Theory Applied The Talkbox
Topic 3 A Brief Review of Physical Acoustics
Spring Mass Model
What is sound
Sound-conducting media
Model of air molecule vibration (Time 1)
Model of air molecule vibration (Time 2)
Model of air molecule vibration (Time 3)
Model of air molecule vibration (Time 4)
Model of air molecule vibration (Time 5)
Model of air molecule vibration
Wave action of molecular motion
Amplitude waveform
Amplitude waveform (2)
Where is pressure in this model
Pressure waveform
Measuring Sound
Measuring Sound Signal Amplitude
Measuring Sound Signal Amplitude (2)
What units do we use to measure signal amplitude
Brief Review The decibel scale
Absolute vs relative measurement
Typical reference values
Howeverhellip
Linear vs logarithmic
Linear vs logarithmic (2)
Logarithmic Scale
Logarithmic Scale (2)
Combining the idea of logarithmic and relativehellip
Intensity vs Pressure
Extending the formula to pressure
Measuring Sound Frequencyperiod
Measuring Sound Frequencyperiod (2)
Phase Uniform Circular Motion
Initiating a sound waves that differ only in phase
Spatial variation in pressure wave
Spatial variation in pressure wave
Spatial variation in pressure wave (2)
Relation between frequency and wavelength
Learning Objectives
Graphic representation of sound
Same sound different graphs
Classification of sounds
Simple periodic sound
Simple periodic sound Graphic appearance
Complex periodic sounds
Complex periodic sounds Graphic appearance
Complex periodic sounds Graphic appearance (2)
Glottal Source
Amplitude vs Phase Spectrum
Amplitude vs Phase Spectrum (2)
(Complex) Aperiodic sounds
Aperiodic sounds Graphic appearance
Aperiodic sounds Graphic appearance (2)
Analysis of complex waves
Learning Objectives (2)
The ldquoenveloperdquo of a sound wave
Waveform envelope
Waveform envelope (2)
Spectrum envelope
Thought Question
Amplitude Spectrum Window Size
ldquoInstantaneousrdquo Amplitude Spectra
(Long Term) Average Amplitude Spectrum
Slide 90
Learning Objectives (3)
The Spectrogram
Building a spectrogram
Building a spectrogram
Building a spectrogram (2)
Two main types of spectrograms
Wide vs Narrow Band Spectrograms
Learning Objectives (4)
What is an ldquoAcousticrdquo Filter
Why might we be interested in filters
Kinds of frequency selective filters
Low Pass Filters
High Pass Filters
Band Pass Filter
Frequency Response Curve (FRC)
Operation of a filter on a signal
Learning Objectives (5)
Free vibration
Forced vibration
Forced vibration (2)
Resonance refers to
Back to the mass spring model
Acoustic Resonance
Acoustic Resonance (2)
Helmholtz Resonator
Actions of a Helmholtz Resonator
Other Acoustic Resonators Tube Resonators
Uniform tube closed at one end
Uniform tube closed at one end (2)
Uniform tube closed at one end
Comparing Helmholtz and tube resonators
Slide 122
Slide 123
Classification of sounds
bull Number of frequency componentsndash Simplendash Complex
bull Relationship of frequency componentsndash Periodicndash Aperiodic
bull Durationndash Continuousndash Transient
Simple periodic sound
bull Simple one frequency componentbull Periodic repeating patternbull Completely characterized byndash amplitudendash period (frequency)ndash phase
bull Other names sinusoid simple harmonic motion pure tone
Simple periodic sound Graphic appearance
From Hillenbrand
Complex periodic sounds
bull Complex gt one frequency componentbull Periodic repeating patternbull Continuousbull Frequencies components have a special relation
ndash Lowest frequency fundamental frequencybull Symbol fo
bull Frequency component with longest periodndash Higher frequency components harmonics
bull integer (whole number) multiples of the fo
Complex periodic sounds Graphic appearance
bull Time domainndash repeating pattern of pressure changendash within the cycle things look complex
bull Frequency domain ndash spectral peaks at evenly spaced frequency
bull Complex gt one frequency componentbull Aperiodic Does not repeat itselfbull Frequency components are not systematically
relatedbull May be ndash Continuousndash Transient
Aperiodic sounds Graphic appearance
bull Time domainndash no repeating pattern of pressure change
bull Frequency domainndash the spectrum is dense ndash No ldquopicket fencerdquo
bull Auditory impression sounds lsquonoisyrsquo
Aperiodic sounds Graphic appearance
From Hillenbrand
>
Analysis of complex wavesbull Waves can be summedbull Complex waves are the sum of simple wavesbull Fourier French Mathematician
ndash Any complex waveform may be formed by summing sinusoids of various frequency amplitude and phase
bull Fourier Analysisndash Provides a unique (only one) solution for a given sound signalndash Is reflected in the amplitude and phase spectrum of the signalndash Reveals the building blocks of complex waves which are sinusoids
Learning Objectives
bull Draw and differentiate the waveform and the waveform envelope
bull Draw and differentiate the amplitude spectrum the phase spectrum and the spectrum envelope
bull Differential between short-term spectra and long-term average spectra
The ldquoenveloperdquo of a sound wave
bull Waveform envelopendash imaginary smooth line that follows the peak of the
amplitude of a sound pressure waveformbull Spectrum envelopendash Imaginary smooth line drawn on top of the
amplitude spectrum
Waveform envelope
From Hillenbrand
Waveform envelope
Time
>
Spectrum envelope
Frequency
Ampl
itude
Thought Question
Can an aperiodic and complex periodic sound have identical
spectrum envelopes
Amplitude Spectrum Window Size
bull ldquoshort-termrdquo vs ldquolong-term averagerdquo amplitude spectrum
ldquoInstantaneousrdquo Amplitude Spectra
(Long Term) Average Amplitude Spectrum
Learning Objectivesbull Describe how the amplitude spectrum and the spectrogram are
relatedbull Identify the axis units of the spectrogrambull Provide some advantages of the spectrogram over the
amplitude spectrumbull Distinguish between a wide band and narrow band spectrogram
and outline the different information each providesbull Distinguish between a harmonic and a formant on a
spectrogrambull Be able to draw stylized (highly simplified) spectrograms based
on spectra and spectrum envelopes
The Spectrogram
Rotate90 degrees
F
AF
A
Building a spectrogram
Rotate it so thatThe amplitude isComing out of thepage
F
A This is really narrow because it is a slice in time
F
Time
Building a spectrogram
Dark bands= amplitudePeaks
Time
Freq
uenc
y
Building a spectrogram
Two main types of spectrograms
bull Narrow-band spectrogramsndash Akin to amplitude spectrums ldquolined uprdquondash Frequency resolution is really sharp
bull Wide-band spectrogramsndash Akin to spectrum envelopes ldquolined uprdquondash Frequency resolution not so sharp
Highlights harmonic structure
Highlights spectrum envelope
Wide vs Narrow Band Spectrograms
Learning Objectives
bull Define an acoustic filterbull Draw and label a frequency response curvebull Draw and differentiate different types of acoustic
filtersbull Define terms such as cutoff frequency center
frequency roll off rate gain and bandwidthbull Define and draw a basic filter system and relate that
to the source-filter theory of speech production
What is an ldquoAcousticrdquo Filter
bull holds back (attenuates) certain sounds and lets other sounds through - selective
Why might we be interested in filters
bull Human vocal tract acts like a frequency selective acoustic filter
bull Human auditory system behaves as a frequency selective filter
bull helps us understand how speech is produced and perceived
Kinds of frequency selective filters
Low-pass filtersndash Lets low frequencies ldquopass throughrdquo and attenuates high
frequencies
High-pass filtersndash Lets high frequencies ldquopass throughrdquo and attenuates low
frequencies
Band-pass filtersndash Lets a particular frequency range ldquopass throughrdquo and
attenuates other frequencies
Low Pass Filters
Frequencylow high
Gai
n
+
-
High Pass Filters
Frequencylow high
Gai
n
+
-
Band Pass Filter
Frequencylow high
Gai
n
+
-
Frequency Response Curve (FRC)
Frequencylow high
Gai
n
+
-
Center frequency
lower cutofffrequency
upper cutoff frequency
passband
3 dB
Operation of a filter on a signal
NOTE Amplitude spectrum describes a soundFrequency response curve describes a filter
Learning Objectivesbull Define resonance free and forced vibrationbull Describe how the pendulum and spring mass models can
help explain resonancebull Outline how mass and stiffness influences the resonant
frequency of a mass spring systembull Outline how acoustic resonators behave like acoustic filtersbull Calculate resonant frequencies of a uniform tube based on
its physical dimensionsbull Describe how the wavelength of the sound determines the
resonant frequency of tube
Free vibration
bull objects tend to vibrate at a characteristic or resonant frequency (RF)
Forced vibration
bull A vibrating system can force a nearby system into vibration
bull The efficiency with which this is accomplished is related to the similarity in the resonant frequency (RF) of the two systems
Forced vibration
bull If the RF of the two systems are the same the amplitude of forced vibration will be large
bull If the RF of the two systems are quite different the amplitude of forced vibration will be small or nonexistent
Resonance refers to
bull The tendency for an object to vibrate at a particular frequency or frequencies
bull The ability of a vibrating system to force another system into vibration
Back to the mass spring model
bull Vibratory frequency of the mass spring determined byndash Massndash Stiffness of the spring
httpphetcoloradoeduensimulationmass-spring-lab
Acoustic Resonance
bull Ideas from mechanical resonance also applies to acoustic systems
bull Acoustic chambers will transmit sound frequencies with more or less efficiency depending upon the physical characteristics
bull Therefore they act as filters passing through (and even amplifying) some frequencies and attentuating others
Acoustic Resonance
bull And since they act as filters they have most of the same features of a filter even though we might use different names
bull Center frequency is often termed the resonant frequency
bull Frequency response curve often termed the resonance curve
Helmholtz Resonator
Actions of a Helmholtz Resonator
Stephen M Tasko
Other Acoustic Resonators Tube Resonators
bull Uniform tubes Factors that influence resonancendash Lengthndash Cross-sectional area along its lengthndash Whether it is closed at either or both ends
Uniform tube closed at one end
Uniform tube closed at one end
Stephen M Tasko
Uniform tube closed at one end
First resonance or formant
F1 = c4lWhere
c=speed of sound (35000 cmsec)l = length of the tube
males ~ 175 cmfemales ~ 14 cm
Higher resonantformant frequencies are odd multiples of F1
For examplebull F1 = (c4l )1
bull F2 = (c4l )3
bull F3 = (c4l )5
Comparing Helmholtz and tube resonators
Resonator Features
Sharply tuned Broadly tuned
Resonator Features
An example of the resonance characteristics of the human vocal tract
Frequency
Gain
SPPA 4030 Speech Science
Topic 1 The Speech Chain
The Speech Chain (Denes amp Pinson 1993)
What information is embedded in the speech signal
Branches of science employed to understand speech communication
Physical Quantities Review An Independent Learning Activity
Assignment 1
Topic 2 The Source-Filter Theory of Speech Production An Intr
Producing Speech
Source-Filter Theory of Speech Production
Vocal tract is a tube that can vary its shape
Source Filter Theory
Same Source Different Filter
Different Source Same Filters
Different Source Same Filters (Human)
Different Source Same Filters (Human) (2)
Different Source Same Filters (Human) (3)
Different Source Same Filters (Human) (4)
Different Source Same Filters (Non-Human)
Different Source Same Filters (Non-Human) (2)
Different Source Same Filters (Non-Human) If it quacks like a
Source Filter Theory Applied Alaryngeal Speech
Source-Filter Theory Applied Esophageal Insufflation Test
Source-Filter Theory Applied Tracheoesophageal (TE) Speech
Source Filter Theory Applied The Talkbox
Source-Filter Theory Applied The Talkbox
Topic 3 A Brief Review of Physical Acoustics
Spring Mass Model
What is sound
Sound-conducting media
Model of air molecule vibration (Time 1)
Model of air molecule vibration (Time 2)
Model of air molecule vibration (Time 3)
Model of air molecule vibration (Time 4)
Model of air molecule vibration (Time 5)
Model of air molecule vibration
Wave action of molecular motion
Amplitude waveform
Amplitude waveform (2)
Where is pressure in this model
Pressure waveform
Measuring Sound
Measuring Sound Signal Amplitude
Measuring Sound Signal Amplitude (2)
What units do we use to measure signal amplitude
Brief Review The decibel scale
Absolute vs relative measurement
Typical reference values
Howeverhellip
Linear vs logarithmic
Linear vs logarithmic (2)
Logarithmic Scale
Logarithmic Scale (2)
Combining the idea of logarithmic and relativehellip
Intensity vs Pressure
Extending the formula to pressure
Measuring Sound Frequencyperiod
Measuring Sound Frequencyperiod (2)
Phase Uniform Circular Motion
Initiating a sound waves that differ only in phase
Spatial variation in pressure wave
Spatial variation in pressure wave
Spatial variation in pressure wave (2)
Relation between frequency and wavelength
Learning Objectives
Graphic representation of sound
Same sound different graphs
Classification of sounds
Simple periodic sound
Simple periodic sound Graphic appearance
Complex periodic sounds
Complex periodic sounds Graphic appearance
Complex periodic sounds Graphic appearance (2)
Glottal Source
Amplitude vs Phase Spectrum
Amplitude vs Phase Spectrum (2)
(Complex) Aperiodic sounds
Aperiodic sounds Graphic appearance
Aperiodic sounds Graphic appearance (2)
Analysis of complex waves
Learning Objectives (2)
The ldquoenveloperdquo of a sound wave
Waveform envelope
Waveform envelope (2)
Spectrum envelope
Thought Question
Amplitude Spectrum Window Size
ldquoInstantaneousrdquo Amplitude Spectra
(Long Term) Average Amplitude Spectrum
Slide 90
Learning Objectives (3)
The Spectrogram
Building a spectrogram
Building a spectrogram
Building a spectrogram (2)
Two main types of spectrograms
Wide vs Narrow Band Spectrograms
Learning Objectives (4)
What is an ldquoAcousticrdquo Filter
Why might we be interested in filters
Kinds of frequency selective filters
Low Pass Filters
High Pass Filters
Band Pass Filter
Frequency Response Curve (FRC)
Operation of a filter on a signal
Learning Objectives (5)
Free vibration
Forced vibration
Forced vibration (2)
Resonance refers to
Back to the mass spring model
Acoustic Resonance
Acoustic Resonance (2)
Helmholtz Resonator
Actions of a Helmholtz Resonator
Other Acoustic Resonators Tube Resonators
Uniform tube closed at one end
Uniform tube closed at one end (2)
Uniform tube closed at one end
Comparing Helmholtz and tube resonators
Slide 122
Slide 123
Simple periodic sound
bull Simple one frequency componentbull Periodic repeating patternbull Completely characterized byndash amplitudendash period (frequency)ndash phase
bull Other names sinusoid simple harmonic motion pure tone
Simple periodic sound Graphic appearance
From Hillenbrand
Complex periodic sounds
bull Complex gt one frequency componentbull Periodic repeating patternbull Continuousbull Frequencies components have a special relation
ndash Lowest frequency fundamental frequencybull Symbol fo
bull Frequency component with longest periodndash Higher frequency components harmonics
bull integer (whole number) multiples of the fo
Complex periodic sounds Graphic appearance
bull Time domainndash repeating pattern of pressure changendash within the cycle things look complex
bull Frequency domain ndash spectral peaks at evenly spaced frequency
bull Complex gt one frequency componentbull Aperiodic Does not repeat itselfbull Frequency components are not systematically
relatedbull May be ndash Continuousndash Transient
Aperiodic sounds Graphic appearance
bull Time domainndash no repeating pattern of pressure change
bull Frequency domainndash the spectrum is dense ndash No ldquopicket fencerdquo
bull Auditory impression sounds lsquonoisyrsquo
Aperiodic sounds Graphic appearance
From Hillenbrand
>
Analysis of complex wavesbull Waves can be summedbull Complex waves are the sum of simple wavesbull Fourier French Mathematician
ndash Any complex waveform may be formed by summing sinusoids of various frequency amplitude and phase
bull Fourier Analysisndash Provides a unique (only one) solution for a given sound signalndash Is reflected in the amplitude and phase spectrum of the signalndash Reveals the building blocks of complex waves which are sinusoids
Learning Objectives
bull Draw and differentiate the waveform and the waveform envelope
bull Draw and differentiate the amplitude spectrum the phase spectrum and the spectrum envelope
bull Differential between short-term spectra and long-term average spectra
The ldquoenveloperdquo of a sound wave
bull Waveform envelopendash imaginary smooth line that follows the peak of the
amplitude of a sound pressure waveformbull Spectrum envelopendash Imaginary smooth line drawn on top of the
amplitude spectrum
Waveform envelope
From Hillenbrand
Waveform envelope
Time
>
Spectrum envelope
Frequency
Ampl
itude
Thought Question
Can an aperiodic and complex periodic sound have identical
spectrum envelopes
Amplitude Spectrum Window Size
bull ldquoshort-termrdquo vs ldquolong-term averagerdquo amplitude spectrum
ldquoInstantaneousrdquo Amplitude Spectra
(Long Term) Average Amplitude Spectrum
Learning Objectivesbull Describe how the amplitude spectrum and the spectrogram are
relatedbull Identify the axis units of the spectrogrambull Provide some advantages of the spectrogram over the
amplitude spectrumbull Distinguish between a wide band and narrow band spectrogram
and outline the different information each providesbull Distinguish between a harmonic and a formant on a
spectrogrambull Be able to draw stylized (highly simplified) spectrograms based
on spectra and spectrum envelopes
The Spectrogram
Rotate90 degrees
F
AF
A
Building a spectrogram
Rotate it so thatThe amplitude isComing out of thepage
F
A This is really narrow because it is a slice in time
F
Time
Building a spectrogram
Dark bands= amplitudePeaks
Time
Freq
uenc
y
Building a spectrogram
Two main types of spectrograms
bull Narrow-band spectrogramsndash Akin to amplitude spectrums ldquolined uprdquondash Frequency resolution is really sharp
bull Wide-band spectrogramsndash Akin to spectrum envelopes ldquolined uprdquondash Frequency resolution not so sharp
Highlights harmonic structure
Highlights spectrum envelope
Wide vs Narrow Band Spectrograms
Learning Objectives
bull Define an acoustic filterbull Draw and label a frequency response curvebull Draw and differentiate different types of acoustic
filtersbull Define terms such as cutoff frequency center
frequency roll off rate gain and bandwidthbull Define and draw a basic filter system and relate that
to the source-filter theory of speech production
What is an ldquoAcousticrdquo Filter
bull holds back (attenuates) certain sounds and lets other sounds through - selective
Why might we be interested in filters
bull Human vocal tract acts like a frequency selective acoustic filter
bull Human auditory system behaves as a frequency selective filter
bull helps us understand how speech is produced and perceived
Kinds of frequency selective filters
Low-pass filtersndash Lets low frequencies ldquopass throughrdquo and attenuates high
frequencies
High-pass filtersndash Lets high frequencies ldquopass throughrdquo and attenuates low
frequencies
Band-pass filtersndash Lets a particular frequency range ldquopass throughrdquo and
attenuates other frequencies
Low Pass Filters
Frequencylow high
Gai
n
+
-
High Pass Filters
Frequencylow high
Gai
n
+
-
Band Pass Filter
Frequencylow high
Gai
n
+
-
Frequency Response Curve (FRC)
Frequencylow high
Gai
n
+
-
Center frequency
lower cutofffrequency
upper cutoff frequency
passband
3 dB
Operation of a filter on a signal
NOTE Amplitude spectrum describes a soundFrequency response curve describes a filter
Learning Objectivesbull Define resonance free and forced vibrationbull Describe how the pendulum and spring mass models can
help explain resonancebull Outline how mass and stiffness influences the resonant
frequency of a mass spring systembull Outline how acoustic resonators behave like acoustic filtersbull Calculate resonant frequencies of a uniform tube based on
its physical dimensionsbull Describe how the wavelength of the sound determines the
resonant frequency of tube
Free vibration
bull objects tend to vibrate at a characteristic or resonant frequency (RF)
Forced vibration
bull A vibrating system can force a nearby system into vibration
bull The efficiency with which this is accomplished is related to the similarity in the resonant frequency (RF) of the two systems
Forced vibration
bull If the RF of the two systems are the same the amplitude of forced vibration will be large
bull If the RF of the two systems are quite different the amplitude of forced vibration will be small or nonexistent
Resonance refers to
bull The tendency for an object to vibrate at a particular frequency or frequencies
bull The ability of a vibrating system to force another system into vibration
Back to the mass spring model
bull Vibratory frequency of the mass spring determined byndash Massndash Stiffness of the spring
httpphetcoloradoeduensimulationmass-spring-lab
Acoustic Resonance
bull Ideas from mechanical resonance also applies to acoustic systems
bull Acoustic chambers will transmit sound frequencies with more or less efficiency depending upon the physical characteristics
bull Therefore they act as filters passing through (and even amplifying) some frequencies and attentuating others
Acoustic Resonance
bull And since they act as filters they have most of the same features of a filter even though we might use different names
bull Center frequency is often termed the resonant frequency
bull Frequency response curve often termed the resonance curve
Helmholtz Resonator
Actions of a Helmholtz Resonator
Stephen M Tasko
Other Acoustic Resonators Tube Resonators
bull Uniform tubes Factors that influence resonancendash Lengthndash Cross-sectional area along its lengthndash Whether it is closed at either or both ends
Uniform tube closed at one end
Uniform tube closed at one end
Stephen M Tasko
Uniform tube closed at one end
First resonance or formant
F1 = c4lWhere
c=speed of sound (35000 cmsec)l = length of the tube
males ~ 175 cmfemales ~ 14 cm
Higher resonantformant frequencies are odd multiples of F1
For examplebull F1 = (c4l )1
bull F2 = (c4l )3
bull F3 = (c4l )5
Comparing Helmholtz and tube resonators
Resonator Features
Sharply tuned Broadly tuned
Resonator Features
An example of the resonance characteristics of the human vocal tract
Frequency
Gain
SPPA 4030 Speech Science
Topic 1 The Speech Chain
The Speech Chain (Denes amp Pinson 1993)
What information is embedded in the speech signal
Branches of science employed to understand speech communication
Physical Quantities Review An Independent Learning Activity
Assignment 1
Topic 2 The Source-Filter Theory of Speech Production An Intr
Producing Speech
Source-Filter Theory of Speech Production
Vocal tract is a tube that can vary its shape
Source Filter Theory
Same Source Different Filter
Different Source Same Filters
Different Source Same Filters (Human)
Different Source Same Filters (Human) (2)
Different Source Same Filters (Human) (3)
Different Source Same Filters (Human) (4)
Different Source Same Filters (Non-Human)
Different Source Same Filters (Non-Human) (2)
Different Source Same Filters (Non-Human) If it quacks like a
Source Filter Theory Applied Alaryngeal Speech
Source-Filter Theory Applied Esophageal Insufflation Test
Source-Filter Theory Applied Tracheoesophageal (TE) Speech
Source Filter Theory Applied The Talkbox
Source-Filter Theory Applied The Talkbox
Topic 3 A Brief Review of Physical Acoustics
Spring Mass Model
What is sound
Sound-conducting media
Model of air molecule vibration (Time 1)
Model of air molecule vibration (Time 2)
Model of air molecule vibration (Time 3)
Model of air molecule vibration (Time 4)
Model of air molecule vibration (Time 5)
Model of air molecule vibration
Wave action of molecular motion
Amplitude waveform
Amplitude waveform (2)
Where is pressure in this model
Pressure waveform
Measuring Sound
Measuring Sound Signal Amplitude
Measuring Sound Signal Amplitude (2)
What units do we use to measure signal amplitude
Brief Review The decibel scale
Absolute vs relative measurement
Typical reference values
Howeverhellip
Linear vs logarithmic
Linear vs logarithmic (2)
Logarithmic Scale
Logarithmic Scale (2)
Combining the idea of logarithmic and relativehellip
Intensity vs Pressure
Extending the formula to pressure
Measuring Sound Frequencyperiod
Measuring Sound Frequencyperiod (2)
Phase Uniform Circular Motion
Initiating a sound waves that differ only in phase
Spatial variation in pressure wave
Spatial variation in pressure wave
Spatial variation in pressure wave (2)
Relation between frequency and wavelength
Learning Objectives
Graphic representation of sound
Same sound different graphs
Classification of sounds
Simple periodic sound
Simple periodic sound Graphic appearance
Complex periodic sounds
Complex periodic sounds Graphic appearance
Complex periodic sounds Graphic appearance (2)
Glottal Source
Amplitude vs Phase Spectrum
Amplitude vs Phase Spectrum (2)
(Complex) Aperiodic sounds
Aperiodic sounds Graphic appearance
Aperiodic sounds Graphic appearance (2)
Analysis of complex waves
Learning Objectives (2)
The ldquoenveloperdquo of a sound wave
Waveform envelope
Waveform envelope (2)
Spectrum envelope
Thought Question
Amplitude Spectrum Window Size
ldquoInstantaneousrdquo Amplitude Spectra
(Long Term) Average Amplitude Spectrum
Slide 90
Learning Objectives (3)
The Spectrogram
Building a spectrogram
Building a spectrogram
Building a spectrogram (2)
Two main types of spectrograms
Wide vs Narrow Band Spectrograms
Learning Objectives (4)
What is an ldquoAcousticrdquo Filter
Why might we be interested in filters
Kinds of frequency selective filters
Low Pass Filters
High Pass Filters
Band Pass Filter
Frequency Response Curve (FRC)
Operation of a filter on a signal
Learning Objectives (5)
Free vibration
Forced vibration
Forced vibration (2)
Resonance refers to
Back to the mass spring model
Acoustic Resonance
Acoustic Resonance (2)
Helmholtz Resonator
Actions of a Helmholtz Resonator
Other Acoustic Resonators Tube Resonators
Uniform tube closed at one end
Uniform tube closed at one end (2)
Uniform tube closed at one end
Comparing Helmholtz and tube resonators
Slide 122
Slide 123
Simple periodic sound Graphic appearance
From Hillenbrand
Complex periodic sounds
bull Complex gt one frequency componentbull Periodic repeating patternbull Continuousbull Frequencies components have a special relation
ndash Lowest frequency fundamental frequencybull Symbol fo
bull Frequency component with longest periodndash Higher frequency components harmonics
bull integer (whole number) multiples of the fo
Complex periodic sounds Graphic appearance
bull Time domainndash repeating pattern of pressure changendash within the cycle things look complex
bull Frequency domain ndash spectral peaks at evenly spaced frequency
bull Complex gt one frequency componentbull Aperiodic Does not repeat itselfbull Frequency components are not systematically
relatedbull May be ndash Continuousndash Transient
Aperiodic sounds Graphic appearance
bull Time domainndash no repeating pattern of pressure change
bull Frequency domainndash the spectrum is dense ndash No ldquopicket fencerdquo
bull Auditory impression sounds lsquonoisyrsquo
Aperiodic sounds Graphic appearance
From Hillenbrand
>
Analysis of complex wavesbull Waves can be summedbull Complex waves are the sum of simple wavesbull Fourier French Mathematician
ndash Any complex waveform may be formed by summing sinusoids of various frequency amplitude and phase
bull Fourier Analysisndash Provides a unique (only one) solution for a given sound signalndash Is reflected in the amplitude and phase spectrum of the signalndash Reveals the building blocks of complex waves which are sinusoids
Learning Objectives
bull Draw and differentiate the waveform and the waveform envelope
bull Draw and differentiate the amplitude spectrum the phase spectrum and the spectrum envelope
bull Differential between short-term spectra and long-term average spectra
The ldquoenveloperdquo of a sound wave
bull Waveform envelopendash imaginary smooth line that follows the peak of the
amplitude of a sound pressure waveformbull Spectrum envelopendash Imaginary smooth line drawn on top of the
amplitude spectrum
Waveform envelope
From Hillenbrand
Waveform envelope
Time
>
Spectrum envelope
Frequency
Ampl
itude
Thought Question
Can an aperiodic and complex periodic sound have identical
spectrum envelopes
Amplitude Spectrum Window Size
bull ldquoshort-termrdquo vs ldquolong-term averagerdquo amplitude spectrum
ldquoInstantaneousrdquo Amplitude Spectra
(Long Term) Average Amplitude Spectrum
Learning Objectivesbull Describe how the amplitude spectrum and the spectrogram are
relatedbull Identify the axis units of the spectrogrambull Provide some advantages of the spectrogram over the
amplitude spectrumbull Distinguish between a wide band and narrow band spectrogram
and outline the different information each providesbull Distinguish between a harmonic and a formant on a
spectrogrambull Be able to draw stylized (highly simplified) spectrograms based
on spectra and spectrum envelopes
The Spectrogram
Rotate90 degrees
F
AF
A
Building a spectrogram
Rotate it so thatThe amplitude isComing out of thepage
F
A This is really narrow because it is a slice in time
F
Time
Building a spectrogram
Dark bands= amplitudePeaks
Time
Freq
uenc
y
Building a spectrogram
Two main types of spectrograms
bull Narrow-band spectrogramsndash Akin to amplitude spectrums ldquolined uprdquondash Frequency resolution is really sharp
bull Wide-band spectrogramsndash Akin to spectrum envelopes ldquolined uprdquondash Frequency resolution not so sharp
Highlights harmonic structure
Highlights spectrum envelope
Wide vs Narrow Band Spectrograms
Learning Objectives
bull Define an acoustic filterbull Draw and label a frequency response curvebull Draw and differentiate different types of acoustic
filtersbull Define terms such as cutoff frequency center
frequency roll off rate gain and bandwidthbull Define and draw a basic filter system and relate that
to the source-filter theory of speech production
What is an ldquoAcousticrdquo Filter
bull holds back (attenuates) certain sounds and lets other sounds through - selective
Why might we be interested in filters
bull Human vocal tract acts like a frequency selective acoustic filter
bull Human auditory system behaves as a frequency selective filter
bull helps us understand how speech is produced and perceived
Kinds of frequency selective filters
Low-pass filtersndash Lets low frequencies ldquopass throughrdquo and attenuates high
frequencies
High-pass filtersndash Lets high frequencies ldquopass throughrdquo and attenuates low
frequencies
Band-pass filtersndash Lets a particular frequency range ldquopass throughrdquo and
attenuates other frequencies
Low Pass Filters
Frequencylow high
Gai
n
+
-
High Pass Filters
Frequencylow high
Gai
n
+
-
Band Pass Filter
Frequencylow high
Gai
n
+
-
Frequency Response Curve (FRC)
Frequencylow high
Gai
n
+
-
Center frequency
lower cutofffrequency
upper cutoff frequency
passband
3 dB
Operation of a filter on a signal
NOTE Amplitude spectrum describes a soundFrequency response curve describes a filter
Learning Objectivesbull Define resonance free and forced vibrationbull Describe how the pendulum and spring mass models can
help explain resonancebull Outline how mass and stiffness influences the resonant
frequency of a mass spring systembull Outline how acoustic resonators behave like acoustic filtersbull Calculate resonant frequencies of a uniform tube based on
its physical dimensionsbull Describe how the wavelength of the sound determines the
resonant frequency of tube
Free vibration
bull objects tend to vibrate at a characteristic or resonant frequency (RF)
Forced vibration
bull A vibrating system can force a nearby system into vibration
bull The efficiency with which this is accomplished is related to the similarity in the resonant frequency (RF) of the two systems
Forced vibration
bull If the RF of the two systems are the same the amplitude of forced vibration will be large
bull If the RF of the two systems are quite different the amplitude of forced vibration will be small or nonexistent
Resonance refers to
bull The tendency for an object to vibrate at a particular frequency or frequencies
bull The ability of a vibrating system to force another system into vibration
Back to the mass spring model
bull Vibratory frequency of the mass spring determined byndash Massndash Stiffness of the spring
httpphetcoloradoeduensimulationmass-spring-lab
Acoustic Resonance
bull Ideas from mechanical resonance also applies to acoustic systems
bull Acoustic chambers will transmit sound frequencies with more or less efficiency depending upon the physical characteristics
bull Therefore they act as filters passing through (and even amplifying) some frequencies and attentuating others
Acoustic Resonance
bull And since they act as filters they have most of the same features of a filter even though we might use different names
bull Center frequency is often termed the resonant frequency
bull Frequency response curve often termed the resonance curve
Helmholtz Resonator
Actions of a Helmholtz Resonator
Stephen M Tasko
Other Acoustic Resonators Tube Resonators
bull Uniform tubes Factors that influence resonancendash Lengthndash Cross-sectional area along its lengthndash Whether it is closed at either or both ends
Uniform tube closed at one end
Uniform tube closed at one end
Stephen M Tasko
Uniform tube closed at one end
First resonance or formant
F1 = c4lWhere
c=speed of sound (35000 cmsec)l = length of the tube
males ~ 175 cmfemales ~ 14 cm
Higher resonantformant frequencies are odd multiples of F1
For examplebull F1 = (c4l )1
bull F2 = (c4l )3
bull F3 = (c4l )5
Comparing Helmholtz and tube resonators
Resonator Features
Sharply tuned Broadly tuned
Resonator Features
An example of the resonance characteristics of the human vocal tract
Frequency
Gain
SPPA 4030 Speech Science
Topic 1 The Speech Chain
The Speech Chain (Denes amp Pinson 1993)
What information is embedded in the speech signal
Branches of science employed to understand speech communication
Physical Quantities Review An Independent Learning Activity
Assignment 1
Topic 2 The Source-Filter Theory of Speech Production An Intr
Producing Speech
Source-Filter Theory of Speech Production
Vocal tract is a tube that can vary its shape
Source Filter Theory
Same Source Different Filter
Different Source Same Filters
Different Source Same Filters (Human)
Different Source Same Filters (Human) (2)
Different Source Same Filters (Human) (3)
Different Source Same Filters (Human) (4)
Different Source Same Filters (Non-Human)
Different Source Same Filters (Non-Human) (2)
Different Source Same Filters (Non-Human) If it quacks like a
Source Filter Theory Applied Alaryngeal Speech
Source-Filter Theory Applied Esophageal Insufflation Test
Source-Filter Theory Applied Tracheoesophageal (TE) Speech
Source Filter Theory Applied The Talkbox
Source-Filter Theory Applied The Talkbox
Topic 3 A Brief Review of Physical Acoustics
Spring Mass Model
What is sound
Sound-conducting media
Model of air molecule vibration (Time 1)
Model of air molecule vibration (Time 2)
Model of air molecule vibration (Time 3)
Model of air molecule vibration (Time 4)
Model of air molecule vibration (Time 5)
Model of air molecule vibration
Wave action of molecular motion
Amplitude waveform
Amplitude waveform (2)
Where is pressure in this model
Pressure waveform
Measuring Sound
Measuring Sound Signal Amplitude
Measuring Sound Signal Amplitude (2)
What units do we use to measure signal amplitude
Brief Review The decibel scale
Absolute vs relative measurement
Typical reference values
Howeverhellip
Linear vs logarithmic
Linear vs logarithmic (2)
Logarithmic Scale
Logarithmic Scale (2)
Combining the idea of logarithmic and relativehellip
Intensity vs Pressure
Extending the formula to pressure
Measuring Sound Frequencyperiod
Measuring Sound Frequencyperiod (2)
Phase Uniform Circular Motion
Initiating a sound waves that differ only in phase
Spatial variation in pressure wave
Spatial variation in pressure wave
Spatial variation in pressure wave (2)
Relation between frequency and wavelength
Learning Objectives
Graphic representation of sound
Same sound different graphs
Classification of sounds
Simple periodic sound
Simple periodic sound Graphic appearance
Complex periodic sounds
Complex periodic sounds Graphic appearance
Complex periodic sounds Graphic appearance (2)
Glottal Source
Amplitude vs Phase Spectrum
Amplitude vs Phase Spectrum (2)
(Complex) Aperiodic sounds
Aperiodic sounds Graphic appearance
Aperiodic sounds Graphic appearance (2)
Analysis of complex waves
Learning Objectives (2)
The ldquoenveloperdquo of a sound wave
Waveform envelope
Waveform envelope (2)
Spectrum envelope
Thought Question
Amplitude Spectrum Window Size
ldquoInstantaneousrdquo Amplitude Spectra
(Long Term) Average Amplitude Spectrum
Slide 90
Learning Objectives (3)
The Spectrogram
Building a spectrogram
Building a spectrogram
Building a spectrogram (2)
Two main types of spectrograms
Wide vs Narrow Band Spectrograms
Learning Objectives (4)
What is an ldquoAcousticrdquo Filter
Why might we be interested in filters
Kinds of frequency selective filters
Low Pass Filters
High Pass Filters
Band Pass Filter
Frequency Response Curve (FRC)
Operation of a filter on a signal
Learning Objectives (5)
Free vibration
Forced vibration
Forced vibration (2)
Resonance refers to
Back to the mass spring model
Acoustic Resonance
Acoustic Resonance (2)
Helmholtz Resonator
Actions of a Helmholtz Resonator
Other Acoustic Resonators Tube Resonators
Uniform tube closed at one end
Uniform tube closed at one end (2)
Uniform tube closed at one end
Comparing Helmholtz and tube resonators
Slide 122
Slide 123
Complex periodic sounds
bull Complex gt one frequency componentbull Periodic repeating patternbull Continuousbull Frequencies components have a special relation
ndash Lowest frequency fundamental frequencybull Symbol fo
bull Frequency component with longest periodndash Higher frequency components harmonics
bull integer (whole number) multiples of the fo
Complex periodic sounds Graphic appearance
bull Time domainndash repeating pattern of pressure changendash within the cycle things look complex
bull Frequency domain ndash spectral peaks at evenly spaced frequency
bull Complex gt one frequency componentbull Aperiodic Does not repeat itselfbull Frequency components are not systematically
relatedbull May be ndash Continuousndash Transient
Aperiodic sounds Graphic appearance
bull Time domainndash no repeating pattern of pressure change
bull Frequency domainndash the spectrum is dense ndash No ldquopicket fencerdquo
bull Auditory impression sounds lsquonoisyrsquo
Aperiodic sounds Graphic appearance
From Hillenbrand
>
Analysis of complex wavesbull Waves can be summedbull Complex waves are the sum of simple wavesbull Fourier French Mathematician
ndash Any complex waveform may be formed by summing sinusoids of various frequency amplitude and phase
bull Fourier Analysisndash Provides a unique (only one) solution for a given sound signalndash Is reflected in the amplitude and phase spectrum of the signalndash Reveals the building blocks of complex waves which are sinusoids
Learning Objectives
bull Draw and differentiate the waveform and the waveform envelope
bull Draw and differentiate the amplitude spectrum the phase spectrum and the spectrum envelope
bull Differential between short-term spectra and long-term average spectra
The ldquoenveloperdquo of a sound wave
bull Waveform envelopendash imaginary smooth line that follows the peak of the
amplitude of a sound pressure waveformbull Spectrum envelopendash Imaginary smooth line drawn on top of the
amplitude spectrum
Waveform envelope
From Hillenbrand
Waveform envelope
Time
>
Spectrum envelope
Frequency
Ampl
itude
Thought Question
Can an aperiodic and complex periodic sound have identical
spectrum envelopes
Amplitude Spectrum Window Size
bull ldquoshort-termrdquo vs ldquolong-term averagerdquo amplitude spectrum
ldquoInstantaneousrdquo Amplitude Spectra
(Long Term) Average Amplitude Spectrum
Learning Objectivesbull Describe how the amplitude spectrum and the spectrogram are
relatedbull Identify the axis units of the spectrogrambull Provide some advantages of the spectrogram over the
amplitude spectrumbull Distinguish between a wide band and narrow band spectrogram
and outline the different information each providesbull Distinguish between a harmonic and a formant on a
spectrogrambull Be able to draw stylized (highly simplified) spectrograms based
on spectra and spectrum envelopes
The Spectrogram
Rotate90 degrees
F
AF
A
Building a spectrogram
Rotate it so thatThe amplitude isComing out of thepage
F
A This is really narrow because it is a slice in time
F
Time
Building a spectrogram
Dark bands= amplitudePeaks
Time
Freq
uenc
y
Building a spectrogram
Two main types of spectrograms
bull Narrow-band spectrogramsndash Akin to amplitude spectrums ldquolined uprdquondash Frequency resolution is really sharp
bull Wide-band spectrogramsndash Akin to spectrum envelopes ldquolined uprdquondash Frequency resolution not so sharp
Highlights harmonic structure
Highlights spectrum envelope
Wide vs Narrow Band Spectrograms
Learning Objectives
bull Define an acoustic filterbull Draw and label a frequency response curvebull Draw and differentiate different types of acoustic
filtersbull Define terms such as cutoff frequency center
frequency roll off rate gain and bandwidthbull Define and draw a basic filter system and relate that
to the source-filter theory of speech production
What is an ldquoAcousticrdquo Filter
bull holds back (attenuates) certain sounds and lets other sounds through - selective
Why might we be interested in filters
bull Human vocal tract acts like a frequency selective acoustic filter
bull Human auditory system behaves as a frequency selective filter
bull helps us understand how speech is produced and perceived
Kinds of frequency selective filters
Low-pass filtersndash Lets low frequencies ldquopass throughrdquo and attenuates high
frequencies
High-pass filtersndash Lets high frequencies ldquopass throughrdquo and attenuates low
frequencies
Band-pass filtersndash Lets a particular frequency range ldquopass throughrdquo and
attenuates other frequencies
Low Pass Filters
Frequencylow high
Gai
n
+
-
High Pass Filters
Frequencylow high
Gai
n
+
-
Band Pass Filter
Frequencylow high
Gai
n
+
-
Frequency Response Curve (FRC)
Frequencylow high
Gai
n
+
-
Center frequency
lower cutofffrequency
upper cutoff frequency
passband
3 dB
Operation of a filter on a signal
NOTE Amplitude spectrum describes a soundFrequency response curve describes a filter
Learning Objectivesbull Define resonance free and forced vibrationbull Describe how the pendulum and spring mass models can
help explain resonancebull Outline how mass and stiffness influences the resonant
frequency of a mass spring systembull Outline how acoustic resonators behave like acoustic filtersbull Calculate resonant frequencies of a uniform tube based on
its physical dimensionsbull Describe how the wavelength of the sound determines the
resonant frequency of tube
Free vibration
bull objects tend to vibrate at a characteristic or resonant frequency (RF)
Forced vibration
bull A vibrating system can force a nearby system into vibration
bull The efficiency with which this is accomplished is related to the similarity in the resonant frequency (RF) of the two systems
Forced vibration
bull If the RF of the two systems are the same the amplitude of forced vibration will be large
bull If the RF of the two systems are quite different the amplitude of forced vibration will be small or nonexistent
Resonance refers to
bull The tendency for an object to vibrate at a particular frequency or frequencies
bull The ability of a vibrating system to force another system into vibration
Back to the mass spring model
bull Vibratory frequency of the mass spring determined byndash Massndash Stiffness of the spring
httpphetcoloradoeduensimulationmass-spring-lab
Acoustic Resonance
bull Ideas from mechanical resonance also applies to acoustic systems
bull Acoustic chambers will transmit sound frequencies with more or less efficiency depending upon the physical characteristics
bull Therefore they act as filters passing through (and even amplifying) some frequencies and attentuating others
Acoustic Resonance
bull And since they act as filters they have most of the same features of a filter even though we might use different names
bull Center frequency is often termed the resonant frequency
bull Frequency response curve often termed the resonance curve
Helmholtz Resonator
Actions of a Helmholtz Resonator
Stephen M Tasko
Other Acoustic Resonators Tube Resonators
bull Uniform tubes Factors that influence resonancendash Lengthndash Cross-sectional area along its lengthndash Whether it is closed at either or both ends
Uniform tube closed at one end
Uniform tube closed at one end
Stephen M Tasko
Uniform tube closed at one end
First resonance or formant
F1 = c4lWhere
c=speed of sound (35000 cmsec)l = length of the tube
males ~ 175 cmfemales ~ 14 cm
Higher resonantformant frequencies are odd multiples of F1
For examplebull F1 = (c4l )1
bull F2 = (c4l )3
bull F3 = (c4l )5
Comparing Helmholtz and tube resonators
Resonator Features
Sharply tuned Broadly tuned
Resonator Features
An example of the resonance characteristics of the human vocal tract
Frequency
Gain
SPPA 4030 Speech Science
Topic 1 The Speech Chain
The Speech Chain (Denes amp Pinson 1993)
What information is embedded in the speech signal
Branches of science employed to understand speech communication
Physical Quantities Review An Independent Learning Activity
Assignment 1
Topic 2 The Source-Filter Theory of Speech Production An Intr
Producing Speech
Source-Filter Theory of Speech Production
Vocal tract is a tube that can vary its shape
Source Filter Theory
Same Source Different Filter
Different Source Same Filters
Different Source Same Filters (Human)
Different Source Same Filters (Human) (2)
Different Source Same Filters (Human) (3)
Different Source Same Filters (Human) (4)
Different Source Same Filters (Non-Human)
Different Source Same Filters (Non-Human) (2)
Different Source Same Filters (Non-Human) If it quacks like a
Source Filter Theory Applied Alaryngeal Speech
Source-Filter Theory Applied Esophageal Insufflation Test
Source-Filter Theory Applied Tracheoesophageal (TE) Speech
Source Filter Theory Applied The Talkbox
Source-Filter Theory Applied The Talkbox
Topic 3 A Brief Review of Physical Acoustics
Spring Mass Model
What is sound
Sound-conducting media
Model of air molecule vibration (Time 1)
Model of air molecule vibration (Time 2)
Model of air molecule vibration (Time 3)
Model of air molecule vibration (Time 4)
Model of air molecule vibration (Time 5)
Model of air molecule vibration
Wave action of molecular motion
Amplitude waveform
Amplitude waveform (2)
Where is pressure in this model
Pressure waveform
Measuring Sound
Measuring Sound Signal Amplitude
Measuring Sound Signal Amplitude (2)
What units do we use to measure signal amplitude
Brief Review The decibel scale
Absolute vs relative measurement
Typical reference values
Howeverhellip
Linear vs logarithmic
Linear vs logarithmic (2)
Logarithmic Scale
Logarithmic Scale (2)
Combining the idea of logarithmic and relativehellip
Intensity vs Pressure
Extending the formula to pressure
Measuring Sound Frequencyperiod
Measuring Sound Frequencyperiod (2)
Phase Uniform Circular Motion
Initiating a sound waves that differ only in phase
Spatial variation in pressure wave
Spatial variation in pressure wave
Spatial variation in pressure wave (2)
Relation between frequency and wavelength
Learning Objectives
Graphic representation of sound
Same sound different graphs
Classification of sounds
Simple periodic sound
Simple periodic sound Graphic appearance
Complex periodic sounds
Complex periodic sounds Graphic appearance
Complex periodic sounds Graphic appearance (2)
Glottal Source
Amplitude vs Phase Spectrum
Amplitude vs Phase Spectrum (2)
(Complex) Aperiodic sounds
Aperiodic sounds Graphic appearance
Aperiodic sounds Graphic appearance (2)
Analysis of complex waves
Learning Objectives (2)
The ldquoenveloperdquo of a sound wave
Waveform envelope
Waveform envelope (2)
Spectrum envelope
Thought Question
Amplitude Spectrum Window Size
ldquoInstantaneousrdquo Amplitude Spectra
(Long Term) Average Amplitude Spectrum
Slide 90
Learning Objectives (3)
The Spectrogram
Building a spectrogram
Building a spectrogram
Building a spectrogram (2)
Two main types of spectrograms
Wide vs Narrow Band Spectrograms
Learning Objectives (4)
What is an ldquoAcousticrdquo Filter
Why might we be interested in filters
Kinds of frequency selective filters
Low Pass Filters
High Pass Filters
Band Pass Filter
Frequency Response Curve (FRC)
Operation of a filter on a signal
Learning Objectives (5)
Free vibration
Forced vibration
Forced vibration (2)
Resonance refers to
Back to the mass spring model
Acoustic Resonance
Acoustic Resonance (2)
Helmholtz Resonator
Actions of a Helmholtz Resonator
Other Acoustic Resonators Tube Resonators
Uniform tube closed at one end
Uniform tube closed at one end (2)
Uniform tube closed at one end
Comparing Helmholtz and tube resonators
Slide 122
Slide 123
Complex periodic sounds Graphic appearance
bull Time domainndash repeating pattern of pressure changendash within the cycle things look complex
bull Frequency domain ndash spectral peaks at evenly spaced frequency
bull Complex gt one frequency componentbull Aperiodic Does not repeat itselfbull Frequency components are not systematically
relatedbull May be ndash Continuousndash Transient
Aperiodic sounds Graphic appearance
bull Time domainndash no repeating pattern of pressure change
bull Frequency domainndash the spectrum is dense ndash No ldquopicket fencerdquo
bull Auditory impression sounds lsquonoisyrsquo
Aperiodic sounds Graphic appearance
From Hillenbrand
>
Analysis of complex wavesbull Waves can be summedbull Complex waves are the sum of simple wavesbull Fourier French Mathematician
ndash Any complex waveform may be formed by summing sinusoids of various frequency amplitude and phase
bull Fourier Analysisndash Provides a unique (only one) solution for a given sound signalndash Is reflected in the amplitude and phase spectrum of the signalndash Reveals the building blocks of complex waves which are sinusoids
Learning Objectives
bull Draw and differentiate the waveform and the waveform envelope
bull Draw and differentiate the amplitude spectrum the phase spectrum and the spectrum envelope
bull Differential between short-term spectra and long-term average spectra
The ldquoenveloperdquo of a sound wave
bull Waveform envelopendash imaginary smooth line that follows the peak of the
amplitude of a sound pressure waveformbull Spectrum envelopendash Imaginary smooth line drawn on top of the
amplitude spectrum
Waveform envelope
From Hillenbrand
Waveform envelope
Time
>
Spectrum envelope
Frequency
Ampl
itude
Thought Question
Can an aperiodic and complex periodic sound have identical
spectrum envelopes
Amplitude Spectrum Window Size
bull ldquoshort-termrdquo vs ldquolong-term averagerdquo amplitude spectrum
ldquoInstantaneousrdquo Amplitude Spectra
(Long Term) Average Amplitude Spectrum
Learning Objectivesbull Describe how the amplitude spectrum and the spectrogram are
relatedbull Identify the axis units of the spectrogrambull Provide some advantages of the spectrogram over the
amplitude spectrumbull Distinguish between a wide band and narrow band spectrogram
and outline the different information each providesbull Distinguish between a harmonic and a formant on a
spectrogrambull Be able to draw stylized (highly simplified) spectrograms based
on spectra and spectrum envelopes
The Spectrogram
Rotate90 degrees
F
AF
A
Building a spectrogram
Rotate it so thatThe amplitude isComing out of thepage
F
A This is really narrow because it is a slice in time
F
Time
Building a spectrogram
Dark bands= amplitudePeaks
Time
Freq
uenc
y
Building a spectrogram
Two main types of spectrograms
bull Narrow-band spectrogramsndash Akin to amplitude spectrums ldquolined uprdquondash Frequency resolution is really sharp
bull Wide-band spectrogramsndash Akin to spectrum envelopes ldquolined uprdquondash Frequency resolution not so sharp
Highlights harmonic structure
Highlights spectrum envelope
Wide vs Narrow Band Spectrograms
Learning Objectives
bull Define an acoustic filterbull Draw and label a frequency response curvebull Draw and differentiate different types of acoustic
filtersbull Define terms such as cutoff frequency center
frequency roll off rate gain and bandwidthbull Define and draw a basic filter system and relate that
to the source-filter theory of speech production
What is an ldquoAcousticrdquo Filter
bull holds back (attenuates) certain sounds and lets other sounds through - selective
Why might we be interested in filters
bull Human vocal tract acts like a frequency selective acoustic filter
bull Human auditory system behaves as a frequency selective filter
bull helps us understand how speech is produced and perceived
Kinds of frequency selective filters
Low-pass filtersndash Lets low frequencies ldquopass throughrdquo and attenuates high
frequencies
High-pass filtersndash Lets high frequencies ldquopass throughrdquo and attenuates low
frequencies
Band-pass filtersndash Lets a particular frequency range ldquopass throughrdquo and
attenuates other frequencies
Low Pass Filters
Frequencylow high
Gai
n
+
-
High Pass Filters
Frequencylow high
Gai
n
+
-
Band Pass Filter
Frequencylow high
Gai
n
+
-
Frequency Response Curve (FRC)
Frequencylow high
Gai
n
+
-
Center frequency
lower cutofffrequency
upper cutoff frequency
passband
3 dB
Operation of a filter on a signal
NOTE Amplitude spectrum describes a soundFrequency response curve describes a filter
Learning Objectivesbull Define resonance free and forced vibrationbull Describe how the pendulum and spring mass models can
help explain resonancebull Outline how mass and stiffness influences the resonant
frequency of a mass spring systembull Outline how acoustic resonators behave like acoustic filtersbull Calculate resonant frequencies of a uniform tube based on
its physical dimensionsbull Describe how the wavelength of the sound determines the
resonant frequency of tube
Free vibration
bull objects tend to vibrate at a characteristic or resonant frequency (RF)
Forced vibration
bull A vibrating system can force a nearby system into vibration
bull The efficiency with which this is accomplished is related to the similarity in the resonant frequency (RF) of the two systems
Forced vibration
bull If the RF of the two systems are the same the amplitude of forced vibration will be large
bull If the RF of the two systems are quite different the amplitude of forced vibration will be small or nonexistent
Resonance refers to
bull The tendency for an object to vibrate at a particular frequency or frequencies
bull The ability of a vibrating system to force another system into vibration
Back to the mass spring model
bull Vibratory frequency of the mass spring determined byndash Massndash Stiffness of the spring
httpphetcoloradoeduensimulationmass-spring-lab
Acoustic Resonance
bull Ideas from mechanical resonance also applies to acoustic systems
bull Acoustic chambers will transmit sound frequencies with more or less efficiency depending upon the physical characteristics
bull Therefore they act as filters passing through (and even amplifying) some frequencies and attentuating others
Acoustic Resonance
bull And since they act as filters they have most of the same features of a filter even though we might use different names
bull Center frequency is often termed the resonant frequency
bull Frequency response curve often termed the resonance curve
Helmholtz Resonator
Actions of a Helmholtz Resonator
Stephen M Tasko
Other Acoustic Resonators Tube Resonators
bull Uniform tubes Factors that influence resonancendash Lengthndash Cross-sectional area along its lengthndash Whether it is closed at either or both ends
Uniform tube closed at one end
Uniform tube closed at one end
Stephen M Tasko
Uniform tube closed at one end
First resonance or formant
F1 = c4lWhere
c=speed of sound (35000 cmsec)l = length of the tube
males ~ 175 cmfemales ~ 14 cm
Higher resonantformant frequencies are odd multiples of F1
For examplebull F1 = (c4l )1
bull F2 = (c4l )3
bull F3 = (c4l )5
Comparing Helmholtz and tube resonators
Resonator Features
Sharply tuned Broadly tuned
Resonator Features
An example of the resonance characteristics of the human vocal tract
Frequency
Gain
SPPA 4030 Speech Science
Topic 1 The Speech Chain
The Speech Chain (Denes amp Pinson 1993)
What information is embedded in the speech signal
Branches of science employed to understand speech communication
Physical Quantities Review An Independent Learning Activity
Assignment 1
Topic 2 The Source-Filter Theory of Speech Production An Intr
Producing Speech
Source-Filter Theory of Speech Production
Vocal tract is a tube that can vary its shape
Source Filter Theory
Same Source Different Filter
Different Source Same Filters
Different Source Same Filters (Human)
Different Source Same Filters (Human) (2)
Different Source Same Filters (Human) (3)
Different Source Same Filters (Human) (4)
Different Source Same Filters (Non-Human)
Different Source Same Filters (Non-Human) (2)
Different Source Same Filters (Non-Human) If it quacks like a
Source Filter Theory Applied Alaryngeal Speech
Source-Filter Theory Applied Esophageal Insufflation Test
Source-Filter Theory Applied Tracheoesophageal (TE) Speech
Source Filter Theory Applied The Talkbox
Source-Filter Theory Applied The Talkbox
Topic 3 A Brief Review of Physical Acoustics
Spring Mass Model
What is sound
Sound-conducting media
Model of air molecule vibration (Time 1)
Model of air molecule vibration (Time 2)
Model of air molecule vibration (Time 3)
Model of air molecule vibration (Time 4)
Model of air molecule vibration (Time 5)
Model of air molecule vibration
Wave action of molecular motion
Amplitude waveform
Amplitude waveform (2)
Where is pressure in this model
Pressure waveform
Measuring Sound
Measuring Sound Signal Amplitude
Measuring Sound Signal Amplitude (2)
What units do we use to measure signal amplitude
Brief Review The decibel scale
Absolute vs relative measurement
Typical reference values
Howeverhellip
Linear vs logarithmic
Linear vs logarithmic (2)
Logarithmic Scale
Logarithmic Scale (2)
Combining the idea of logarithmic and relativehellip
Intensity vs Pressure
Extending the formula to pressure
Measuring Sound Frequencyperiod
Measuring Sound Frequencyperiod (2)
Phase Uniform Circular Motion
Initiating a sound waves that differ only in phase
Spatial variation in pressure wave
Spatial variation in pressure wave
Spatial variation in pressure wave (2)
Relation between frequency and wavelength
Learning Objectives
Graphic representation of sound
Same sound different graphs
Classification of sounds
Simple periodic sound
Simple periodic sound Graphic appearance
Complex periodic sounds
Complex periodic sounds Graphic appearance
Complex periodic sounds Graphic appearance (2)
Glottal Source
Amplitude vs Phase Spectrum
Amplitude vs Phase Spectrum (2)
(Complex) Aperiodic sounds
Aperiodic sounds Graphic appearance
Aperiodic sounds Graphic appearance (2)
Analysis of complex waves
Learning Objectives (2)
The ldquoenveloperdquo of a sound wave
Waveform envelope
Waveform envelope (2)
Spectrum envelope
Thought Question
Amplitude Spectrum Window Size
ldquoInstantaneousrdquo Amplitude Spectra
(Long Term) Average Amplitude Spectrum
Slide 90
Learning Objectives (3)
The Spectrogram
Building a spectrogram
Building a spectrogram
Building a spectrogram (2)
Two main types of spectrograms
Wide vs Narrow Band Spectrograms
Learning Objectives (4)
What is an ldquoAcousticrdquo Filter
Why might we be interested in filters
Kinds of frequency selective filters
Low Pass Filters
High Pass Filters
Band Pass Filter
Frequency Response Curve (FRC)
Operation of a filter on a signal
Learning Objectives (5)
Free vibration
Forced vibration
Forced vibration (2)
Resonance refers to
Back to the mass spring model
Acoustic Resonance
Acoustic Resonance (2)
Helmholtz Resonator
Actions of a Helmholtz Resonator
Other Acoustic Resonators Tube Resonators
Uniform tube closed at one end
Uniform tube closed at one end (2)
Uniform tube closed at one end
Comparing Helmholtz and tube resonators
Slide 122
Slide 123
Complex periodic sounds Graphic appearance
From Hillenbrand
Glottal Source
Time FrequencyAm
plitu
de
Ampl
itude
>
Amplitude vs Phase Spectrum
Amplitude spectrum different
Phase spectrum same
From Hillenbrand
>
>
Amplitude vs Phase Spectrum
Amplitude spectrum same
Phase spectrum different
From Hillenbrand
>
>
(Complex) Aperiodic sounds
bull Complex gt one frequency componentbull Aperiodic Does not repeat itselfbull Frequency components are not systematically
relatedbull May be ndash Continuousndash Transient
Aperiodic sounds Graphic appearance
bull Time domainndash no repeating pattern of pressure change
bull Frequency domainndash the spectrum is dense ndash No ldquopicket fencerdquo
bull Auditory impression sounds lsquonoisyrsquo
Aperiodic sounds Graphic appearance
From Hillenbrand
>
Analysis of complex wavesbull Waves can be summedbull Complex waves are the sum of simple wavesbull Fourier French Mathematician
ndash Any complex waveform may be formed by summing sinusoids of various frequency amplitude and phase
bull Fourier Analysisndash Provides a unique (only one) solution for a given sound signalndash Is reflected in the amplitude and phase spectrum of the signalndash Reveals the building blocks of complex waves which are sinusoids
Learning Objectives
bull Draw and differentiate the waveform and the waveform envelope
bull Draw and differentiate the amplitude spectrum the phase spectrum and the spectrum envelope
bull Differential between short-term spectra and long-term average spectra
The ldquoenveloperdquo of a sound wave
bull Waveform envelopendash imaginary smooth line that follows the peak of the
amplitude of a sound pressure waveformbull Spectrum envelopendash Imaginary smooth line drawn on top of the
amplitude spectrum
Waveform envelope
From Hillenbrand
Waveform envelope
Time
>
Spectrum envelope
Frequency
Ampl
itude
Thought Question
Can an aperiodic and complex periodic sound have identical
spectrum envelopes
Amplitude Spectrum Window Size
bull ldquoshort-termrdquo vs ldquolong-term averagerdquo amplitude spectrum
ldquoInstantaneousrdquo Amplitude Spectra
(Long Term) Average Amplitude Spectrum
Learning Objectivesbull Describe how the amplitude spectrum and the spectrogram are
relatedbull Identify the axis units of the spectrogrambull Provide some advantages of the spectrogram over the
amplitude spectrumbull Distinguish between a wide band and narrow band spectrogram
and outline the different information each providesbull Distinguish between a harmonic and a formant on a
spectrogrambull Be able to draw stylized (highly simplified) spectrograms based
on spectra and spectrum envelopes
The Spectrogram
Rotate90 degrees
F
AF
A
Building a spectrogram
Rotate it so thatThe amplitude isComing out of thepage
F
A This is really narrow because it is a slice in time
F
Time
Building a spectrogram
Dark bands= amplitudePeaks
Time
Freq
uenc
y
Building a spectrogram
Two main types of spectrograms
bull Narrow-band spectrogramsndash Akin to amplitude spectrums ldquolined uprdquondash Frequency resolution is really sharp
bull Wide-band spectrogramsndash Akin to spectrum envelopes ldquolined uprdquondash Frequency resolution not so sharp
Highlights harmonic structure
Highlights spectrum envelope
Wide vs Narrow Band Spectrograms
Learning Objectives
bull Define an acoustic filterbull Draw and label a frequency response curvebull Draw and differentiate different types of acoustic
filtersbull Define terms such as cutoff frequency center
frequency roll off rate gain and bandwidthbull Define and draw a basic filter system and relate that
to the source-filter theory of speech production
What is an ldquoAcousticrdquo Filter
bull holds back (attenuates) certain sounds and lets other sounds through - selective
Why might we be interested in filters
bull Human vocal tract acts like a frequency selective acoustic filter
bull Human auditory system behaves as a frequency selective filter
bull helps us understand how speech is produced and perceived
Kinds of frequency selective filters
Low-pass filtersndash Lets low frequencies ldquopass throughrdquo and attenuates high
frequencies
High-pass filtersndash Lets high frequencies ldquopass throughrdquo and attenuates low
frequencies
Band-pass filtersndash Lets a particular frequency range ldquopass throughrdquo and
attenuates other frequencies
Low Pass Filters
Frequencylow high
Gai
n
+
-
High Pass Filters
Frequencylow high
Gai
n
+
-
Band Pass Filter
Frequencylow high
Gai
n
+
-
Frequency Response Curve (FRC)
Frequencylow high
Gai
n
+
-
Center frequency
lower cutofffrequency
upper cutoff frequency
passband
3 dB
Operation of a filter on a signal
NOTE Amplitude spectrum describes a soundFrequency response curve describes a filter
Learning Objectivesbull Define resonance free and forced vibrationbull Describe how the pendulum and spring mass models can
help explain resonancebull Outline how mass and stiffness influences the resonant
frequency of a mass spring systembull Outline how acoustic resonators behave like acoustic filtersbull Calculate resonant frequencies of a uniform tube based on
its physical dimensionsbull Describe how the wavelength of the sound determines the
resonant frequency of tube
Free vibration
bull objects tend to vibrate at a characteristic or resonant frequency (RF)
Forced vibration
bull A vibrating system can force a nearby system into vibration
bull The efficiency with which this is accomplished is related to the similarity in the resonant frequency (RF) of the two systems
Forced vibration
bull If the RF of the two systems are the same the amplitude of forced vibration will be large
bull If the RF of the two systems are quite different the amplitude of forced vibration will be small or nonexistent
Resonance refers to
bull The tendency for an object to vibrate at a particular frequency or frequencies
bull The ability of a vibrating system to force another system into vibration
Back to the mass spring model
bull Vibratory frequency of the mass spring determined byndash Massndash Stiffness of the spring
httpphetcoloradoeduensimulationmass-spring-lab
Acoustic Resonance
bull Ideas from mechanical resonance also applies to acoustic systems
bull Acoustic chambers will transmit sound frequencies with more or less efficiency depending upon the physical characteristics
bull Therefore they act as filters passing through (and even amplifying) some frequencies and attentuating others
Acoustic Resonance
bull And since they act as filters they have most of the same features of a filter even though we might use different names
bull Center frequency is often termed the resonant frequency
bull Frequency response curve often termed the resonance curve
Helmholtz Resonator
Actions of a Helmholtz Resonator
Stephen M Tasko
Other Acoustic Resonators Tube Resonators
bull Uniform tubes Factors that influence resonancendash Lengthndash Cross-sectional area along its lengthndash Whether it is closed at either or both ends
Uniform tube closed at one end
Uniform tube closed at one end
Stephen M Tasko
Uniform tube closed at one end
First resonance or formant
F1 = c4lWhere
c=speed of sound (35000 cmsec)l = length of the tube
males ~ 175 cmfemales ~ 14 cm
Higher resonantformant frequencies are odd multiples of F1
For examplebull F1 = (c4l )1
bull F2 = (c4l )3
bull F3 = (c4l )5
Comparing Helmholtz and tube resonators
Resonator Features
Sharply tuned Broadly tuned
Resonator Features
An example of the resonance characteristics of the human vocal tract
Frequency
Gain
SPPA 4030 Speech Science
Topic 1 The Speech Chain
The Speech Chain (Denes amp Pinson 1993)
What information is embedded in the speech signal
Branches of science employed to understand speech communication
Physical Quantities Review An Independent Learning Activity
Assignment 1
Topic 2 The Source-Filter Theory of Speech Production An Intr
Producing Speech
Source-Filter Theory of Speech Production
Vocal tract is a tube that can vary its shape
Source Filter Theory
Same Source Different Filter
Different Source Same Filters
Different Source Same Filters (Human)
Different Source Same Filters (Human) (2)
Different Source Same Filters (Human) (3)
Different Source Same Filters (Human) (4)
Different Source Same Filters (Non-Human)
Different Source Same Filters (Non-Human) (2)
Different Source Same Filters (Non-Human) If it quacks like a
Source Filter Theory Applied Alaryngeal Speech
Source-Filter Theory Applied Esophageal Insufflation Test
Source-Filter Theory Applied Tracheoesophageal (TE) Speech
Source Filter Theory Applied The Talkbox
Source-Filter Theory Applied The Talkbox
Topic 3 A Brief Review of Physical Acoustics
Spring Mass Model
What is sound
Sound-conducting media
Model of air molecule vibration (Time 1)
Model of air molecule vibration (Time 2)
Model of air molecule vibration (Time 3)
Model of air molecule vibration (Time 4)
Model of air molecule vibration (Time 5)
Model of air molecule vibration
Wave action of molecular motion
Amplitude waveform
Amplitude waveform (2)
Where is pressure in this model
Pressure waveform
Measuring Sound
Measuring Sound Signal Amplitude
Measuring Sound Signal Amplitude (2)
What units do we use to measure signal amplitude
Brief Review The decibel scale
Absolute vs relative measurement
Typical reference values
Howeverhellip
Linear vs logarithmic
Linear vs logarithmic (2)
Logarithmic Scale
Logarithmic Scale (2)
Combining the idea of logarithmic and relativehellip
Intensity vs Pressure
Extending the formula to pressure
Measuring Sound Frequencyperiod
Measuring Sound Frequencyperiod (2)
Phase Uniform Circular Motion
Initiating a sound waves that differ only in phase
Spatial variation in pressure wave
Spatial variation in pressure wave
Spatial variation in pressure wave (2)
Relation between frequency and wavelength
Learning Objectives
Graphic representation of sound
Same sound different graphs
Classification of sounds
Simple periodic sound
Simple periodic sound Graphic appearance
Complex periodic sounds
Complex periodic sounds Graphic appearance
Complex periodic sounds Graphic appearance (2)
Glottal Source
Amplitude vs Phase Spectrum
Amplitude vs Phase Spectrum (2)
(Complex) Aperiodic sounds
Aperiodic sounds Graphic appearance
Aperiodic sounds Graphic appearance (2)
Analysis of complex waves
Learning Objectives (2)
The ldquoenveloperdquo of a sound wave
Waveform envelope
Waveform envelope (2)
Spectrum envelope
Thought Question
Amplitude Spectrum Window Size
ldquoInstantaneousrdquo Amplitude Spectra
(Long Term) Average Amplitude Spectrum
Slide 90
Learning Objectives (3)
The Spectrogram
Building a spectrogram
Building a spectrogram
Building a spectrogram (2)
Two main types of spectrograms
Wide vs Narrow Band Spectrograms
Learning Objectives (4)
What is an ldquoAcousticrdquo Filter
Why might we be interested in filters
Kinds of frequency selective filters
Low Pass Filters
High Pass Filters
Band Pass Filter
Frequency Response Curve (FRC)
Operation of a filter on a signal
Learning Objectives (5)
Free vibration
Forced vibration
Forced vibration (2)
Resonance refers to
Back to the mass spring model
Acoustic Resonance
Acoustic Resonance (2)
Helmholtz Resonator
Actions of a Helmholtz Resonator
Other Acoustic Resonators Tube Resonators
Uniform tube closed at one end
Uniform tube closed at one end (2)
Uniform tube closed at one end
Comparing Helmholtz and tube resonators
Slide 122
Slide 123
Glottal Source
Time FrequencyAm
plitu
de
Ampl
itude
>
Amplitude vs Phase Spectrum
Amplitude spectrum different
Phase spectrum same
From Hillenbrand
>
>
Amplitude vs Phase Spectrum
Amplitude spectrum same
Phase spectrum different
From Hillenbrand
>
>
(Complex) Aperiodic sounds
bull Complex gt one frequency componentbull Aperiodic Does not repeat itselfbull Frequency components are not systematically
relatedbull May be ndash Continuousndash Transient
Aperiodic sounds Graphic appearance
bull Time domainndash no repeating pattern of pressure change
bull Frequency domainndash the spectrum is dense ndash No ldquopicket fencerdquo
bull Auditory impression sounds lsquonoisyrsquo
Aperiodic sounds Graphic appearance
From Hillenbrand
>
Analysis of complex wavesbull Waves can be summedbull Complex waves are the sum of simple wavesbull Fourier French Mathematician
ndash Any complex waveform may be formed by summing sinusoids of various frequency amplitude and phase
bull Fourier Analysisndash Provides a unique (only one) solution for a given sound signalndash Is reflected in the amplitude and phase spectrum of the signalndash Reveals the building blocks of complex waves which are sinusoids
Learning Objectives
bull Draw and differentiate the waveform and the waveform envelope
bull Draw and differentiate the amplitude spectrum the phase spectrum and the spectrum envelope
bull Differential between short-term spectra and long-term average spectra
The ldquoenveloperdquo of a sound wave
bull Waveform envelopendash imaginary smooth line that follows the peak of the
amplitude of a sound pressure waveformbull Spectrum envelopendash Imaginary smooth line drawn on top of the
amplitude spectrum
Waveform envelope
From Hillenbrand
Waveform envelope
Time
>
Spectrum envelope
Frequency
Ampl
itude
Thought Question
Can an aperiodic and complex periodic sound have identical
spectrum envelopes
Amplitude Spectrum Window Size
bull ldquoshort-termrdquo vs ldquolong-term averagerdquo amplitude spectrum
ldquoInstantaneousrdquo Amplitude Spectra
(Long Term) Average Amplitude Spectrum
Learning Objectivesbull Describe how the amplitude spectrum and the spectrogram are
relatedbull Identify the axis units of the spectrogrambull Provide some advantages of the spectrogram over the
amplitude spectrumbull Distinguish between a wide band and narrow band spectrogram
and outline the different information each providesbull Distinguish between a harmonic and a formant on a
spectrogrambull Be able to draw stylized (highly simplified) spectrograms based
on spectra and spectrum envelopes
The Spectrogram
Rotate90 degrees
F
AF
A
Building a spectrogram
Rotate it so thatThe amplitude isComing out of thepage
F
A This is really narrow because it is a slice in time
F
Time
Building a spectrogram
Dark bands= amplitudePeaks
Time
Freq
uenc
y
Building a spectrogram
Two main types of spectrograms
bull Narrow-band spectrogramsndash Akin to amplitude spectrums ldquolined uprdquondash Frequency resolution is really sharp
bull Wide-band spectrogramsndash Akin to spectrum envelopes ldquolined uprdquondash Frequency resolution not so sharp
Highlights harmonic structure
Highlights spectrum envelope
Wide vs Narrow Band Spectrograms
Learning Objectives
bull Define an acoustic filterbull Draw and label a frequency response curvebull Draw and differentiate different types of acoustic
filtersbull Define terms such as cutoff frequency center
frequency roll off rate gain and bandwidthbull Define and draw a basic filter system and relate that
to the source-filter theory of speech production
What is an ldquoAcousticrdquo Filter
bull holds back (attenuates) certain sounds and lets other sounds through - selective
Why might we be interested in filters
bull Human vocal tract acts like a frequency selective acoustic filter
bull Human auditory system behaves as a frequency selective filter
bull helps us understand how speech is produced and perceived
Kinds of frequency selective filters
Low-pass filtersndash Lets low frequencies ldquopass throughrdquo and attenuates high
frequencies
High-pass filtersndash Lets high frequencies ldquopass throughrdquo and attenuates low
frequencies
Band-pass filtersndash Lets a particular frequency range ldquopass throughrdquo and
attenuates other frequencies
Low Pass Filters
Frequencylow high
Gai
n
+
-
High Pass Filters
Frequencylow high
Gai
n
+
-
Band Pass Filter
Frequencylow high
Gai
n
+
-
Frequency Response Curve (FRC)
Frequencylow high
Gai
n
+
-
Center frequency
lower cutofffrequency
upper cutoff frequency
passband
3 dB
Operation of a filter on a signal
NOTE Amplitude spectrum describes a soundFrequency response curve describes a filter
Learning Objectivesbull Define resonance free and forced vibrationbull Describe how the pendulum and spring mass models can
help explain resonancebull Outline how mass and stiffness influences the resonant
frequency of a mass spring systembull Outline how acoustic resonators behave like acoustic filtersbull Calculate resonant frequencies of a uniform tube based on
its physical dimensionsbull Describe how the wavelength of the sound determines the
resonant frequency of tube
Free vibration
bull objects tend to vibrate at a characteristic or resonant frequency (RF)
Forced vibration
bull A vibrating system can force a nearby system into vibration
bull The efficiency with which this is accomplished is related to the similarity in the resonant frequency (RF) of the two systems
Forced vibration
bull If the RF of the two systems are the same the amplitude of forced vibration will be large
bull If the RF of the two systems are quite different the amplitude of forced vibration will be small or nonexistent
Resonance refers to
bull The tendency for an object to vibrate at a particular frequency or frequencies
bull The ability of a vibrating system to force another system into vibration
Back to the mass spring model
bull Vibratory frequency of the mass spring determined byndash Massndash Stiffness of the spring
httpphetcoloradoeduensimulationmass-spring-lab
Acoustic Resonance
bull Ideas from mechanical resonance also applies to acoustic systems
bull Acoustic chambers will transmit sound frequencies with more or less efficiency depending upon the physical characteristics
bull Therefore they act as filters passing through (and even amplifying) some frequencies and attentuating others
Acoustic Resonance
bull And since they act as filters they have most of the same features of a filter even though we might use different names
bull Center frequency is often termed the resonant frequency
bull Frequency response curve often termed the resonance curve
Helmholtz Resonator
Actions of a Helmholtz Resonator
Stephen M Tasko
Other Acoustic Resonators Tube Resonators
bull Uniform tubes Factors that influence resonancendash Lengthndash Cross-sectional area along its lengthndash Whether it is closed at either or both ends
Uniform tube closed at one end
Uniform tube closed at one end
Stephen M Tasko
Uniform tube closed at one end
First resonance or formant
F1 = c4lWhere
c=speed of sound (35000 cmsec)l = length of the tube
males ~ 175 cmfemales ~ 14 cm
Higher resonantformant frequencies are odd multiples of F1
For examplebull F1 = (c4l )1
bull F2 = (c4l )3
bull F3 = (c4l )5
Comparing Helmholtz and tube resonators
Resonator Features
Sharply tuned Broadly tuned
Resonator Features
An example of the resonance characteristics of the human vocal tract
Frequency
Gain
SPPA 4030 Speech Science
Topic 1 The Speech Chain
The Speech Chain (Denes amp Pinson 1993)
What information is embedded in the speech signal
Branches of science employed to understand speech communication
Physical Quantities Review An Independent Learning Activity
Assignment 1
Topic 2 The Source-Filter Theory of Speech Production An Intr
Producing Speech
Source-Filter Theory of Speech Production
Vocal tract is a tube that can vary its shape
Source Filter Theory
Same Source Different Filter
Different Source Same Filters
Different Source Same Filters (Human)
Different Source Same Filters (Human) (2)
Different Source Same Filters (Human) (3)
Different Source Same Filters (Human) (4)
Different Source Same Filters (Non-Human)
Different Source Same Filters (Non-Human) (2)
Different Source Same Filters (Non-Human) If it quacks like a
Source Filter Theory Applied Alaryngeal Speech
Source-Filter Theory Applied Esophageal Insufflation Test
Source-Filter Theory Applied Tracheoesophageal (TE) Speech
Source Filter Theory Applied The Talkbox
Source-Filter Theory Applied The Talkbox
Topic 3 A Brief Review of Physical Acoustics
Spring Mass Model
What is sound
Sound-conducting media
Model of air molecule vibration (Time 1)
Model of air molecule vibration (Time 2)
Model of air molecule vibration (Time 3)
Model of air molecule vibration (Time 4)
Model of air molecule vibration (Time 5)
Model of air molecule vibration
Wave action of molecular motion
Amplitude waveform
Amplitude waveform (2)
Where is pressure in this model
Pressure waveform
Measuring Sound
Measuring Sound Signal Amplitude
Measuring Sound Signal Amplitude (2)
What units do we use to measure signal amplitude
Brief Review The decibel scale
Absolute vs relative measurement
Typical reference values
Howeverhellip
Linear vs logarithmic
Linear vs logarithmic (2)
Logarithmic Scale
Logarithmic Scale (2)
Combining the idea of logarithmic and relativehellip
Intensity vs Pressure
Extending the formula to pressure
Measuring Sound Frequencyperiod
Measuring Sound Frequencyperiod (2)
Phase Uniform Circular Motion
Initiating a sound waves that differ only in phase
Spatial variation in pressure wave
Spatial variation in pressure wave
Spatial variation in pressure wave (2)
Relation between frequency and wavelength
Learning Objectives
Graphic representation of sound
Same sound different graphs
Classification of sounds
Simple periodic sound
Simple periodic sound Graphic appearance
Complex periodic sounds
Complex periodic sounds Graphic appearance
Complex periodic sounds Graphic appearance (2)
Glottal Source
Amplitude vs Phase Spectrum
Amplitude vs Phase Spectrum (2)
(Complex) Aperiodic sounds
Aperiodic sounds Graphic appearance
Aperiodic sounds Graphic appearance (2)
Analysis of complex waves
Learning Objectives (2)
The ldquoenveloperdquo of a sound wave
Waveform envelope
Waveform envelope (2)
Spectrum envelope
Thought Question
Amplitude Spectrum Window Size
ldquoInstantaneousrdquo Amplitude Spectra
(Long Term) Average Amplitude Spectrum
Slide 90
Learning Objectives (3)
The Spectrogram
Building a spectrogram
Building a spectrogram
Building a spectrogram (2)
Two main types of spectrograms
Wide vs Narrow Band Spectrograms
Learning Objectives (4)
What is an ldquoAcousticrdquo Filter
Why might we be interested in filters
Kinds of frequency selective filters
Low Pass Filters
High Pass Filters
Band Pass Filter
Frequency Response Curve (FRC)
Operation of a filter on a signal
Learning Objectives (5)
Free vibration
Forced vibration
Forced vibration (2)
Resonance refers to
Back to the mass spring model
Acoustic Resonance
Acoustic Resonance (2)
Helmholtz Resonator
Actions of a Helmholtz Resonator
Other Acoustic Resonators Tube Resonators
Uniform tube closed at one end
Uniform tube closed at one end (2)
Uniform tube closed at one end
Comparing Helmholtz and tube resonators
Slide 122
Slide 123
Amplitude vs Phase Spectrum
Amplitude spectrum different
Phase spectrum same
From Hillenbrand
>
>
Amplitude vs Phase Spectrum
Amplitude spectrum same
Phase spectrum different
From Hillenbrand
>
>
(Complex) Aperiodic sounds
bull Complex gt one frequency componentbull Aperiodic Does not repeat itselfbull Frequency components are not systematically
relatedbull May be ndash Continuousndash Transient
Aperiodic sounds Graphic appearance
bull Time domainndash no repeating pattern of pressure change
bull Frequency domainndash the spectrum is dense ndash No ldquopicket fencerdquo
bull Auditory impression sounds lsquonoisyrsquo
Aperiodic sounds Graphic appearance
From Hillenbrand
>
Analysis of complex wavesbull Waves can be summedbull Complex waves are the sum of simple wavesbull Fourier French Mathematician
ndash Any complex waveform may be formed by summing sinusoids of various frequency amplitude and phase
bull Fourier Analysisndash Provides a unique (only one) solution for a given sound signalndash Is reflected in the amplitude and phase spectrum of the signalndash Reveals the building blocks of complex waves which are sinusoids
Learning Objectives
bull Draw and differentiate the waveform and the waveform envelope
bull Draw and differentiate the amplitude spectrum the phase spectrum and the spectrum envelope
bull Differential between short-term spectra and long-term average spectra
The ldquoenveloperdquo of a sound wave
bull Waveform envelopendash imaginary smooth line that follows the peak of the
amplitude of a sound pressure waveformbull Spectrum envelopendash Imaginary smooth line drawn on top of the
amplitude spectrum
Waveform envelope
From Hillenbrand
Waveform envelope
Time
>
Spectrum envelope
Frequency
Ampl
itude
Thought Question
Can an aperiodic and complex periodic sound have identical
spectrum envelopes
Amplitude Spectrum Window Size
bull ldquoshort-termrdquo vs ldquolong-term averagerdquo amplitude spectrum
ldquoInstantaneousrdquo Amplitude Spectra
(Long Term) Average Amplitude Spectrum
Learning Objectivesbull Describe how the amplitude spectrum and the spectrogram are
relatedbull Identify the axis units of the spectrogrambull Provide some advantages of the spectrogram over the
amplitude spectrumbull Distinguish between a wide band and narrow band spectrogram
and outline the different information each providesbull Distinguish between a harmonic and a formant on a
spectrogrambull Be able to draw stylized (highly simplified) spectrograms based
on spectra and spectrum envelopes
The Spectrogram
Rotate90 degrees
F
AF
A
Building a spectrogram
Rotate it so thatThe amplitude isComing out of thepage
F
A This is really narrow because it is a slice in time
F
Time
Building a spectrogram
Dark bands= amplitudePeaks
Time
Freq
uenc
y
Building a spectrogram
Two main types of spectrograms
bull Narrow-band spectrogramsndash Akin to amplitude spectrums ldquolined uprdquondash Frequency resolution is really sharp
bull Wide-band spectrogramsndash Akin to spectrum envelopes ldquolined uprdquondash Frequency resolution not so sharp
Highlights harmonic structure
Highlights spectrum envelope
Wide vs Narrow Band Spectrograms
Learning Objectives
bull Define an acoustic filterbull Draw and label a frequency response curvebull Draw and differentiate different types of acoustic
filtersbull Define terms such as cutoff frequency center
frequency roll off rate gain and bandwidthbull Define and draw a basic filter system and relate that
to the source-filter theory of speech production
What is an ldquoAcousticrdquo Filter
bull holds back (attenuates) certain sounds and lets other sounds through - selective
Why might we be interested in filters
bull Human vocal tract acts like a frequency selective acoustic filter
bull Human auditory system behaves as a frequency selective filter
bull helps us understand how speech is produced and perceived
Kinds of frequency selective filters
Low-pass filtersndash Lets low frequencies ldquopass throughrdquo and attenuates high
frequencies
High-pass filtersndash Lets high frequencies ldquopass throughrdquo and attenuates low
frequencies
Band-pass filtersndash Lets a particular frequency range ldquopass throughrdquo and
attenuates other frequencies
Low Pass Filters
Frequencylow high
Gai
n
+
-
High Pass Filters
Frequencylow high
Gai
n
+
-
Band Pass Filter
Frequencylow high
Gai
n
+
-
Frequency Response Curve (FRC)
Frequencylow high
Gai
n
+
-
Center frequency
lower cutofffrequency
upper cutoff frequency
passband
3 dB
Operation of a filter on a signal
NOTE Amplitude spectrum describes a soundFrequency response curve describes a filter
Learning Objectivesbull Define resonance free and forced vibrationbull Describe how the pendulum and spring mass models can
help explain resonancebull Outline how mass and stiffness influences the resonant
frequency of a mass spring systembull Outline how acoustic resonators behave like acoustic filtersbull Calculate resonant frequencies of a uniform tube based on
its physical dimensionsbull Describe how the wavelength of the sound determines the
resonant frequency of tube
Free vibration
bull objects tend to vibrate at a characteristic or resonant frequency (RF)
Forced vibration
bull A vibrating system can force a nearby system into vibration
bull The efficiency with which this is accomplished is related to the similarity in the resonant frequency (RF) of the two systems
Forced vibration
bull If the RF of the two systems are the same the amplitude of forced vibration will be large
bull If the RF of the two systems are quite different the amplitude of forced vibration will be small or nonexistent
Resonance refers to
bull The tendency for an object to vibrate at a particular frequency or frequencies
bull The ability of a vibrating system to force another system into vibration
Back to the mass spring model
bull Vibratory frequency of the mass spring determined byndash Massndash Stiffness of the spring
httpphetcoloradoeduensimulationmass-spring-lab
Acoustic Resonance
bull Ideas from mechanical resonance also applies to acoustic systems
bull Acoustic chambers will transmit sound frequencies with more or less efficiency depending upon the physical characteristics
bull Therefore they act as filters passing through (and even amplifying) some frequencies and attentuating others
Acoustic Resonance
bull And since they act as filters they have most of the same features of a filter even though we might use different names
bull Center frequency is often termed the resonant frequency
bull Frequency response curve often termed the resonance curve
Helmholtz Resonator
Actions of a Helmholtz Resonator
Stephen M Tasko
Other Acoustic Resonators Tube Resonators
bull Uniform tubes Factors that influence resonancendash Lengthndash Cross-sectional area along its lengthndash Whether it is closed at either or both ends
Uniform tube closed at one end
Uniform tube closed at one end
Stephen M Tasko
Uniform tube closed at one end
First resonance or formant
F1 = c4lWhere
c=speed of sound (35000 cmsec)l = length of the tube
males ~ 175 cmfemales ~ 14 cm
Higher resonantformant frequencies are odd multiples of F1
For examplebull F1 = (c4l )1
bull F2 = (c4l )3
bull F3 = (c4l )5
Comparing Helmholtz and tube resonators
Resonator Features
Sharply tuned Broadly tuned
Resonator Features
An example of the resonance characteristics of the human vocal tract
Frequency
Gain
SPPA 4030 Speech Science
Topic 1 The Speech Chain
The Speech Chain (Denes amp Pinson 1993)
What information is embedded in the speech signal
Branches of science employed to understand speech communication
Physical Quantities Review An Independent Learning Activity
Assignment 1
Topic 2 The Source-Filter Theory of Speech Production An Intr
Producing Speech
Source-Filter Theory of Speech Production
Vocal tract is a tube that can vary its shape
Source Filter Theory
Same Source Different Filter
Different Source Same Filters
Different Source Same Filters (Human)
Different Source Same Filters (Human) (2)
Different Source Same Filters (Human) (3)
Different Source Same Filters (Human) (4)
Different Source Same Filters (Non-Human)
Different Source Same Filters (Non-Human) (2)
Different Source Same Filters (Non-Human) If it quacks like a
Source Filter Theory Applied Alaryngeal Speech
Source-Filter Theory Applied Esophageal Insufflation Test
Source-Filter Theory Applied Tracheoesophageal (TE) Speech
Source Filter Theory Applied The Talkbox
Source-Filter Theory Applied The Talkbox
Topic 3 A Brief Review of Physical Acoustics
Spring Mass Model
What is sound
Sound-conducting media
Model of air molecule vibration (Time 1)
Model of air molecule vibration (Time 2)
Model of air molecule vibration (Time 3)
Model of air molecule vibration (Time 4)
Model of air molecule vibration (Time 5)
Model of air molecule vibration
Wave action of molecular motion
Amplitude waveform
Amplitude waveform (2)
Where is pressure in this model
Pressure waveform
Measuring Sound
Measuring Sound Signal Amplitude
Measuring Sound Signal Amplitude (2)
What units do we use to measure signal amplitude
Brief Review The decibel scale
Absolute vs relative measurement
Typical reference values
Howeverhellip
Linear vs logarithmic
Linear vs logarithmic (2)
Logarithmic Scale
Logarithmic Scale (2)
Combining the idea of logarithmic and relativehellip
Intensity vs Pressure
Extending the formula to pressure
Measuring Sound Frequencyperiod
Measuring Sound Frequencyperiod (2)
Phase Uniform Circular Motion
Initiating a sound waves that differ only in phase
Spatial variation in pressure wave
Spatial variation in pressure wave
Spatial variation in pressure wave (2)
Relation between frequency and wavelength
Learning Objectives
Graphic representation of sound
Same sound different graphs
Classification of sounds
Simple periodic sound
Simple periodic sound Graphic appearance
Complex periodic sounds
Complex periodic sounds Graphic appearance
Complex periodic sounds Graphic appearance (2)
Glottal Source
Amplitude vs Phase Spectrum
Amplitude vs Phase Spectrum (2)
(Complex) Aperiodic sounds
Aperiodic sounds Graphic appearance
Aperiodic sounds Graphic appearance (2)
Analysis of complex waves
Learning Objectives (2)
The ldquoenveloperdquo of a sound wave
Waveform envelope
Waveform envelope (2)
Spectrum envelope
Thought Question
Amplitude Spectrum Window Size
ldquoInstantaneousrdquo Amplitude Spectra
(Long Term) Average Amplitude Spectrum
Slide 90
Learning Objectives (3)
The Spectrogram
Building a spectrogram
Building a spectrogram
Building a spectrogram (2)
Two main types of spectrograms
Wide vs Narrow Band Spectrograms
Learning Objectives (4)
What is an ldquoAcousticrdquo Filter
Why might we be interested in filters
Kinds of frequency selective filters
Low Pass Filters
High Pass Filters
Band Pass Filter
Frequency Response Curve (FRC)
Operation of a filter on a signal
Learning Objectives (5)
Free vibration
Forced vibration
Forced vibration (2)
Resonance refers to
Back to the mass spring model
Acoustic Resonance
Acoustic Resonance (2)
Helmholtz Resonator
Actions of a Helmholtz Resonator
Other Acoustic Resonators Tube Resonators
Uniform tube closed at one end
Uniform tube closed at one end (2)
Uniform tube closed at one end
Comparing Helmholtz and tube resonators
Slide 122
Slide 123
Amplitude vs Phase Spectrum
Amplitude spectrum same
Phase spectrum different
From Hillenbrand
>
>
(Complex) Aperiodic sounds
bull Complex gt one frequency componentbull Aperiodic Does not repeat itselfbull Frequency components are not systematically
relatedbull May be ndash Continuousndash Transient
Aperiodic sounds Graphic appearance
bull Time domainndash no repeating pattern of pressure change
bull Frequency domainndash the spectrum is dense ndash No ldquopicket fencerdquo
bull Auditory impression sounds lsquonoisyrsquo
Aperiodic sounds Graphic appearance
From Hillenbrand
>
Analysis of complex wavesbull Waves can be summedbull Complex waves are the sum of simple wavesbull Fourier French Mathematician
ndash Any complex waveform may be formed by summing sinusoids of various frequency amplitude and phase
bull Fourier Analysisndash Provides a unique (only one) solution for a given sound signalndash Is reflected in the amplitude and phase spectrum of the signalndash Reveals the building blocks of complex waves which are sinusoids
Learning Objectives
bull Draw and differentiate the waveform and the waveform envelope
bull Draw and differentiate the amplitude spectrum the phase spectrum and the spectrum envelope
bull Differential between short-term spectra and long-term average spectra
The ldquoenveloperdquo of a sound wave
bull Waveform envelopendash imaginary smooth line that follows the peak of the
amplitude of a sound pressure waveformbull Spectrum envelopendash Imaginary smooth line drawn on top of the
amplitude spectrum
Waveform envelope
From Hillenbrand
Waveform envelope
Time
>
Spectrum envelope
Frequency
Ampl
itude
Thought Question
Can an aperiodic and complex periodic sound have identical
spectrum envelopes
Amplitude Spectrum Window Size
bull ldquoshort-termrdquo vs ldquolong-term averagerdquo amplitude spectrum
ldquoInstantaneousrdquo Amplitude Spectra
(Long Term) Average Amplitude Spectrum
Learning Objectivesbull Describe how the amplitude spectrum and the spectrogram are
relatedbull Identify the axis units of the spectrogrambull Provide some advantages of the spectrogram over the
amplitude spectrumbull Distinguish between a wide band and narrow band spectrogram
and outline the different information each providesbull Distinguish between a harmonic and a formant on a
spectrogrambull Be able to draw stylized (highly simplified) spectrograms based
on spectra and spectrum envelopes
The Spectrogram
Rotate90 degrees
F
AF
A
Building a spectrogram
Rotate it so thatThe amplitude isComing out of thepage
F
A This is really narrow because it is a slice in time
F
Time
Building a spectrogram
Dark bands= amplitudePeaks
Time
Freq
uenc
y
Building a spectrogram
Two main types of spectrograms
bull Narrow-band spectrogramsndash Akin to amplitude spectrums ldquolined uprdquondash Frequency resolution is really sharp
bull Wide-band spectrogramsndash Akin to spectrum envelopes ldquolined uprdquondash Frequency resolution not so sharp
Highlights harmonic structure
Highlights spectrum envelope
Wide vs Narrow Band Spectrograms
Learning Objectives
bull Define an acoustic filterbull Draw and label a frequency response curvebull Draw and differentiate different types of acoustic
filtersbull Define terms such as cutoff frequency center
frequency roll off rate gain and bandwidthbull Define and draw a basic filter system and relate that
to the source-filter theory of speech production
What is an ldquoAcousticrdquo Filter
bull holds back (attenuates) certain sounds and lets other sounds through - selective
Why might we be interested in filters
bull Human vocal tract acts like a frequency selective acoustic filter
bull Human auditory system behaves as a frequency selective filter
bull helps us understand how speech is produced and perceived
Kinds of frequency selective filters
Low-pass filtersndash Lets low frequencies ldquopass throughrdquo and attenuates high
frequencies
High-pass filtersndash Lets high frequencies ldquopass throughrdquo and attenuates low
frequencies
Band-pass filtersndash Lets a particular frequency range ldquopass throughrdquo and
attenuates other frequencies
Low Pass Filters
Frequencylow high
Gai
n
+
-
High Pass Filters
Frequencylow high
Gai
n
+
-
Band Pass Filter
Frequencylow high
Gai
n
+
-
Frequency Response Curve (FRC)
Frequencylow high
Gai
n
+
-
Center frequency
lower cutofffrequency
upper cutoff frequency
passband
3 dB
Operation of a filter on a signal
NOTE Amplitude spectrum describes a soundFrequency response curve describes a filter
Learning Objectivesbull Define resonance free and forced vibrationbull Describe how the pendulum and spring mass models can
help explain resonancebull Outline how mass and stiffness influences the resonant
frequency of a mass spring systembull Outline how acoustic resonators behave like acoustic filtersbull Calculate resonant frequencies of a uniform tube based on
its physical dimensionsbull Describe how the wavelength of the sound determines the
resonant frequency of tube
Free vibration
bull objects tend to vibrate at a characteristic or resonant frequency (RF)
Forced vibration
bull A vibrating system can force a nearby system into vibration
bull The efficiency with which this is accomplished is related to the similarity in the resonant frequency (RF) of the two systems
Forced vibration
bull If the RF of the two systems are the same the amplitude of forced vibration will be large
bull If the RF of the two systems are quite different the amplitude of forced vibration will be small or nonexistent
Resonance refers to
bull The tendency for an object to vibrate at a particular frequency or frequencies
bull The ability of a vibrating system to force another system into vibration
Back to the mass spring model
bull Vibratory frequency of the mass spring determined byndash Massndash Stiffness of the spring
httpphetcoloradoeduensimulationmass-spring-lab
Acoustic Resonance
bull Ideas from mechanical resonance also applies to acoustic systems
bull Acoustic chambers will transmit sound frequencies with more or less efficiency depending upon the physical characteristics
bull Therefore they act as filters passing through (and even amplifying) some frequencies and attentuating others
Acoustic Resonance
bull And since they act as filters they have most of the same features of a filter even though we might use different names
bull Center frequency is often termed the resonant frequency
bull Frequency response curve often termed the resonance curve
Helmholtz Resonator
Actions of a Helmholtz Resonator
Stephen M Tasko
Other Acoustic Resonators Tube Resonators
bull Uniform tubes Factors that influence resonancendash Lengthndash Cross-sectional area along its lengthndash Whether it is closed at either or both ends
Uniform tube closed at one end
Uniform tube closed at one end
Stephen M Tasko
Uniform tube closed at one end
First resonance or formant
F1 = c4lWhere
c=speed of sound (35000 cmsec)l = length of the tube
males ~ 175 cmfemales ~ 14 cm
Higher resonantformant frequencies are odd multiples of F1
For examplebull F1 = (c4l )1
bull F2 = (c4l )3
bull F3 = (c4l )5
Comparing Helmholtz and tube resonators
Resonator Features
Sharply tuned Broadly tuned
Resonator Features
An example of the resonance characteristics of the human vocal tract
Frequency
Gain
SPPA 4030 Speech Science
Topic 1 The Speech Chain
The Speech Chain (Denes amp Pinson 1993)
What information is embedded in the speech signal
Branches of science employed to understand speech communication
Physical Quantities Review An Independent Learning Activity
Assignment 1
Topic 2 The Source-Filter Theory of Speech Production An Intr
Producing Speech
Source-Filter Theory of Speech Production
Vocal tract is a tube that can vary its shape
Source Filter Theory
Same Source Different Filter
Different Source Same Filters
Different Source Same Filters (Human)
Different Source Same Filters (Human) (2)
Different Source Same Filters (Human) (3)
Different Source Same Filters (Human) (4)
Different Source Same Filters (Non-Human)
Different Source Same Filters (Non-Human) (2)
Different Source Same Filters (Non-Human) If it quacks like a
Source Filter Theory Applied Alaryngeal Speech
Source-Filter Theory Applied Esophageal Insufflation Test
Source-Filter Theory Applied Tracheoesophageal (TE) Speech
Source Filter Theory Applied The Talkbox
Source-Filter Theory Applied The Talkbox
Topic 3 A Brief Review of Physical Acoustics
Spring Mass Model
What is sound
Sound-conducting media
Model of air molecule vibration (Time 1)
Model of air molecule vibration (Time 2)
Model of air molecule vibration (Time 3)
Model of air molecule vibration (Time 4)
Model of air molecule vibration (Time 5)
Model of air molecule vibration
Wave action of molecular motion
Amplitude waveform
Amplitude waveform (2)
Where is pressure in this model
Pressure waveform
Measuring Sound
Measuring Sound Signal Amplitude
Measuring Sound Signal Amplitude (2)
What units do we use to measure signal amplitude
Brief Review The decibel scale
Absolute vs relative measurement
Typical reference values
Howeverhellip
Linear vs logarithmic
Linear vs logarithmic (2)
Logarithmic Scale
Logarithmic Scale (2)
Combining the idea of logarithmic and relativehellip
Intensity vs Pressure
Extending the formula to pressure
Measuring Sound Frequencyperiod
Measuring Sound Frequencyperiod (2)
Phase Uniform Circular Motion
Initiating a sound waves that differ only in phase
Spatial variation in pressure wave
Spatial variation in pressure wave
Spatial variation in pressure wave (2)
Relation between frequency and wavelength
Learning Objectives
Graphic representation of sound
Same sound different graphs
Classification of sounds
Simple periodic sound
Simple periodic sound Graphic appearance
Complex periodic sounds
Complex periodic sounds Graphic appearance
Complex periodic sounds Graphic appearance (2)
Glottal Source
Amplitude vs Phase Spectrum
Amplitude vs Phase Spectrum (2)
(Complex) Aperiodic sounds
Aperiodic sounds Graphic appearance
Aperiodic sounds Graphic appearance (2)
Analysis of complex waves
Learning Objectives (2)
The ldquoenveloperdquo of a sound wave
Waveform envelope
Waveform envelope (2)
Spectrum envelope
Thought Question
Amplitude Spectrum Window Size
ldquoInstantaneousrdquo Amplitude Spectra
(Long Term) Average Amplitude Spectrum
Slide 90
Learning Objectives (3)
The Spectrogram
Building a spectrogram
Building a spectrogram
Building a spectrogram (2)
Two main types of spectrograms
Wide vs Narrow Band Spectrograms
Learning Objectives (4)
What is an ldquoAcousticrdquo Filter
Why might we be interested in filters
Kinds of frequency selective filters
Low Pass Filters
High Pass Filters
Band Pass Filter
Frequency Response Curve (FRC)
Operation of a filter on a signal
Learning Objectives (5)
Free vibration
Forced vibration
Forced vibration (2)
Resonance refers to
Back to the mass spring model
Acoustic Resonance
Acoustic Resonance (2)
Helmholtz Resonator
Actions of a Helmholtz Resonator
Other Acoustic Resonators Tube Resonators
Uniform tube closed at one end
Uniform tube closed at one end (2)
Uniform tube closed at one end
Comparing Helmholtz and tube resonators
Slide 122
Slide 123
(Complex) Aperiodic sounds
bull Complex gt one frequency componentbull Aperiodic Does not repeat itselfbull Frequency components are not systematically
relatedbull May be ndash Continuousndash Transient
Aperiodic sounds Graphic appearance
bull Time domainndash no repeating pattern of pressure change
bull Frequency domainndash the spectrum is dense ndash No ldquopicket fencerdquo
bull Auditory impression sounds lsquonoisyrsquo
Aperiodic sounds Graphic appearance
From Hillenbrand
>
Analysis of complex wavesbull Waves can be summedbull Complex waves are the sum of simple wavesbull Fourier French Mathematician
ndash Any complex waveform may be formed by summing sinusoids of various frequency amplitude and phase
bull Fourier Analysisndash Provides a unique (only one) solution for a given sound signalndash Is reflected in the amplitude and phase spectrum of the signalndash Reveals the building blocks of complex waves which are sinusoids
Learning Objectives
bull Draw and differentiate the waveform and the waveform envelope
bull Draw and differentiate the amplitude spectrum the phase spectrum and the spectrum envelope
bull Differential between short-term spectra and long-term average spectra
The ldquoenveloperdquo of a sound wave
bull Waveform envelopendash imaginary smooth line that follows the peak of the
amplitude of a sound pressure waveformbull Spectrum envelopendash Imaginary smooth line drawn on top of the
amplitude spectrum
Waveform envelope
From Hillenbrand
Waveform envelope
Time
>
Spectrum envelope
Frequency
Ampl
itude
Thought Question
Can an aperiodic and complex periodic sound have identical
spectrum envelopes
Amplitude Spectrum Window Size
bull ldquoshort-termrdquo vs ldquolong-term averagerdquo amplitude spectrum
ldquoInstantaneousrdquo Amplitude Spectra
(Long Term) Average Amplitude Spectrum
Learning Objectivesbull Describe how the amplitude spectrum and the spectrogram are
relatedbull Identify the axis units of the spectrogrambull Provide some advantages of the spectrogram over the
amplitude spectrumbull Distinguish between a wide band and narrow band spectrogram
and outline the different information each providesbull Distinguish between a harmonic and a formant on a
spectrogrambull Be able to draw stylized (highly simplified) spectrograms based
on spectra and spectrum envelopes
The Spectrogram
Rotate90 degrees
F
AF
A
Building a spectrogram
Rotate it so thatThe amplitude isComing out of thepage
F
A This is really narrow because it is a slice in time
F
Time
Building a spectrogram
Dark bands= amplitudePeaks
Time
Freq
uenc
y
Building a spectrogram
Two main types of spectrograms
bull Narrow-band spectrogramsndash Akin to amplitude spectrums ldquolined uprdquondash Frequency resolution is really sharp
bull Wide-band spectrogramsndash Akin to spectrum envelopes ldquolined uprdquondash Frequency resolution not so sharp
Highlights harmonic structure
Highlights spectrum envelope
Wide vs Narrow Band Spectrograms
Learning Objectives
bull Define an acoustic filterbull Draw and label a frequency response curvebull Draw and differentiate different types of acoustic
filtersbull Define terms such as cutoff frequency center
frequency roll off rate gain and bandwidthbull Define and draw a basic filter system and relate that
to the source-filter theory of speech production
What is an ldquoAcousticrdquo Filter
bull holds back (attenuates) certain sounds and lets other sounds through - selective
Why might we be interested in filters
bull Human vocal tract acts like a frequency selective acoustic filter
bull Human auditory system behaves as a frequency selective filter
bull helps us understand how speech is produced and perceived
Kinds of frequency selective filters
Low-pass filtersndash Lets low frequencies ldquopass throughrdquo and attenuates high
frequencies
High-pass filtersndash Lets high frequencies ldquopass throughrdquo and attenuates low
frequencies
Band-pass filtersndash Lets a particular frequency range ldquopass throughrdquo and
attenuates other frequencies
Low Pass Filters
Frequencylow high
Gai
n
+
-
High Pass Filters
Frequencylow high
Gai
n
+
-
Band Pass Filter
Frequencylow high
Gai
n
+
-
Frequency Response Curve (FRC)
Frequencylow high
Gai
n
+
-
Center frequency
lower cutofffrequency
upper cutoff frequency
passband
3 dB
Operation of a filter on a signal
NOTE Amplitude spectrum describes a soundFrequency response curve describes a filter
Learning Objectivesbull Define resonance free and forced vibrationbull Describe how the pendulum and spring mass models can
help explain resonancebull Outline how mass and stiffness influences the resonant
frequency of a mass spring systembull Outline how acoustic resonators behave like acoustic filtersbull Calculate resonant frequencies of a uniform tube based on
its physical dimensionsbull Describe how the wavelength of the sound determines the
resonant frequency of tube
Free vibration
bull objects tend to vibrate at a characteristic or resonant frequency (RF)
Forced vibration
bull A vibrating system can force a nearby system into vibration
bull The efficiency with which this is accomplished is related to the similarity in the resonant frequency (RF) of the two systems
Forced vibration
bull If the RF of the two systems are the same the amplitude of forced vibration will be large
bull If the RF of the two systems are quite different the amplitude of forced vibration will be small or nonexistent
Resonance refers to
bull The tendency for an object to vibrate at a particular frequency or frequencies
bull The ability of a vibrating system to force another system into vibration
Back to the mass spring model
bull Vibratory frequency of the mass spring determined byndash Massndash Stiffness of the spring
httpphetcoloradoeduensimulationmass-spring-lab
Acoustic Resonance
bull Ideas from mechanical resonance also applies to acoustic systems
bull Acoustic chambers will transmit sound frequencies with more or less efficiency depending upon the physical characteristics
bull Therefore they act as filters passing through (and even amplifying) some frequencies and attentuating others
Acoustic Resonance
bull And since they act as filters they have most of the same features of a filter even though we might use different names
bull Center frequency is often termed the resonant frequency
bull Frequency response curve often termed the resonance curve
Helmholtz Resonator
Actions of a Helmholtz Resonator
Stephen M Tasko
Other Acoustic Resonators Tube Resonators
bull Uniform tubes Factors that influence resonancendash Lengthndash Cross-sectional area along its lengthndash Whether it is closed at either or both ends
Uniform tube closed at one end
Uniform tube closed at one end
Stephen M Tasko
Uniform tube closed at one end
First resonance or formant
F1 = c4lWhere
c=speed of sound (35000 cmsec)l = length of the tube
males ~ 175 cmfemales ~ 14 cm
Higher resonantformant frequencies are odd multiples of F1
For examplebull F1 = (c4l )1
bull F2 = (c4l )3
bull F3 = (c4l )5
Comparing Helmholtz and tube resonators
Resonator Features
Sharply tuned Broadly tuned
Resonator Features
An example of the resonance characteristics of the human vocal tract
Frequency
Gain
SPPA 4030 Speech Science
Topic 1 The Speech Chain
The Speech Chain (Denes amp Pinson 1993)
What information is embedded in the speech signal
Branches of science employed to understand speech communication
Physical Quantities Review An Independent Learning Activity
Assignment 1
Topic 2 The Source-Filter Theory of Speech Production An Intr
Producing Speech
Source-Filter Theory of Speech Production
Vocal tract is a tube that can vary its shape
Source Filter Theory
Same Source Different Filter
Different Source Same Filters
Different Source Same Filters (Human)
Different Source Same Filters (Human) (2)
Different Source Same Filters (Human) (3)
Different Source Same Filters (Human) (4)
Different Source Same Filters (Non-Human)
Different Source Same Filters (Non-Human) (2)
Different Source Same Filters (Non-Human) If it quacks like a
Source Filter Theory Applied Alaryngeal Speech
Source-Filter Theory Applied Esophageal Insufflation Test
Source-Filter Theory Applied Tracheoesophageal (TE) Speech
Source Filter Theory Applied The Talkbox
Source-Filter Theory Applied The Talkbox
Topic 3 A Brief Review of Physical Acoustics
Spring Mass Model
What is sound
Sound-conducting media
Model of air molecule vibration (Time 1)
Model of air molecule vibration (Time 2)
Model of air molecule vibration (Time 3)
Model of air molecule vibration (Time 4)
Model of air molecule vibration (Time 5)
Model of air molecule vibration
Wave action of molecular motion
Amplitude waveform
Amplitude waveform (2)
Where is pressure in this model
Pressure waveform
Measuring Sound
Measuring Sound Signal Amplitude
Measuring Sound Signal Amplitude (2)
What units do we use to measure signal amplitude
Brief Review The decibel scale
Absolute vs relative measurement
Typical reference values
Howeverhellip
Linear vs logarithmic
Linear vs logarithmic (2)
Logarithmic Scale
Logarithmic Scale (2)
Combining the idea of logarithmic and relativehellip
Intensity vs Pressure
Extending the formula to pressure
Measuring Sound Frequencyperiod
Measuring Sound Frequencyperiod (2)
Phase Uniform Circular Motion
Initiating a sound waves that differ only in phase
Spatial variation in pressure wave
Spatial variation in pressure wave
Spatial variation in pressure wave (2)
Relation between frequency and wavelength
Learning Objectives
Graphic representation of sound
Same sound different graphs
Classification of sounds
Simple periodic sound
Simple periodic sound Graphic appearance
Complex periodic sounds
Complex periodic sounds Graphic appearance
Complex periodic sounds Graphic appearance (2)
Glottal Source
Amplitude vs Phase Spectrum
Amplitude vs Phase Spectrum (2)
(Complex) Aperiodic sounds
Aperiodic sounds Graphic appearance
Aperiodic sounds Graphic appearance (2)
Analysis of complex waves
Learning Objectives (2)
The ldquoenveloperdquo of a sound wave
Waveform envelope
Waveform envelope (2)
Spectrum envelope
Thought Question
Amplitude Spectrum Window Size
ldquoInstantaneousrdquo Amplitude Spectra
(Long Term) Average Amplitude Spectrum
Slide 90
Learning Objectives (3)
The Spectrogram
Building a spectrogram
Building a spectrogram
Building a spectrogram (2)
Two main types of spectrograms
Wide vs Narrow Band Spectrograms
Learning Objectives (4)
What is an ldquoAcousticrdquo Filter
Why might we be interested in filters
Kinds of frequency selective filters
Low Pass Filters
High Pass Filters
Band Pass Filter
Frequency Response Curve (FRC)
Operation of a filter on a signal
Learning Objectives (5)
Free vibration
Forced vibration
Forced vibration (2)
Resonance refers to
Back to the mass spring model
Acoustic Resonance
Acoustic Resonance (2)
Helmholtz Resonator
Actions of a Helmholtz Resonator
Other Acoustic Resonators Tube Resonators
Uniform tube closed at one end
Uniform tube closed at one end (2)
Uniform tube closed at one end
Comparing Helmholtz and tube resonators
Slide 122
Slide 123
Aperiodic sounds Graphic appearance
bull Time domainndash no repeating pattern of pressure change
bull Frequency domainndash the spectrum is dense ndash No ldquopicket fencerdquo
bull Auditory impression sounds lsquonoisyrsquo
Aperiodic sounds Graphic appearance
From Hillenbrand
>
Analysis of complex wavesbull Waves can be summedbull Complex waves are the sum of simple wavesbull Fourier French Mathematician
ndash Any complex waveform may be formed by summing sinusoids of various frequency amplitude and phase
bull Fourier Analysisndash Provides a unique (only one) solution for a given sound signalndash Is reflected in the amplitude and phase spectrum of the signalndash Reveals the building blocks of complex waves which are sinusoids
Learning Objectives
bull Draw and differentiate the waveform and the waveform envelope
bull Draw and differentiate the amplitude spectrum the phase spectrum and the spectrum envelope
bull Differential between short-term spectra and long-term average spectra
The ldquoenveloperdquo of a sound wave
bull Waveform envelopendash imaginary smooth line that follows the peak of the
amplitude of a sound pressure waveformbull Spectrum envelopendash Imaginary smooth line drawn on top of the
amplitude spectrum
Waveform envelope
From Hillenbrand
Waveform envelope
Time
>
Spectrum envelope
Frequency
Ampl
itude
Thought Question
Can an aperiodic and complex periodic sound have identical
spectrum envelopes
Amplitude Spectrum Window Size
bull ldquoshort-termrdquo vs ldquolong-term averagerdquo amplitude spectrum
ldquoInstantaneousrdquo Amplitude Spectra
(Long Term) Average Amplitude Spectrum
Learning Objectivesbull Describe how the amplitude spectrum and the spectrogram are
relatedbull Identify the axis units of the spectrogrambull Provide some advantages of the spectrogram over the
amplitude spectrumbull Distinguish between a wide band and narrow band spectrogram
and outline the different information each providesbull Distinguish between a harmonic and a formant on a
spectrogrambull Be able to draw stylized (highly simplified) spectrograms based
on spectra and spectrum envelopes
The Spectrogram
Rotate90 degrees
F
AF
A
Building a spectrogram
Rotate it so thatThe amplitude isComing out of thepage
F
A This is really narrow because it is a slice in time
F
Time
Building a spectrogram
Dark bands= amplitudePeaks
Time
Freq
uenc
y
Building a spectrogram
Two main types of spectrograms
bull Narrow-band spectrogramsndash Akin to amplitude spectrums ldquolined uprdquondash Frequency resolution is really sharp
bull Wide-band spectrogramsndash Akin to spectrum envelopes ldquolined uprdquondash Frequency resolution not so sharp
Highlights harmonic structure
Highlights spectrum envelope
Wide vs Narrow Band Spectrograms
Learning Objectives
bull Define an acoustic filterbull Draw and label a frequency response curvebull Draw and differentiate different types of acoustic
filtersbull Define terms such as cutoff frequency center
frequency roll off rate gain and bandwidthbull Define and draw a basic filter system and relate that
to the source-filter theory of speech production
What is an ldquoAcousticrdquo Filter
bull holds back (attenuates) certain sounds and lets other sounds through - selective
Why might we be interested in filters
bull Human vocal tract acts like a frequency selective acoustic filter
bull Human auditory system behaves as a frequency selective filter
bull helps us understand how speech is produced and perceived
Kinds of frequency selective filters
Low-pass filtersndash Lets low frequencies ldquopass throughrdquo and attenuates high
frequencies
High-pass filtersndash Lets high frequencies ldquopass throughrdquo and attenuates low
frequencies
Band-pass filtersndash Lets a particular frequency range ldquopass throughrdquo and
attenuates other frequencies
Low Pass Filters
Frequencylow high
Gai
n
+
-
High Pass Filters
Frequencylow high
Gai
n
+
-
Band Pass Filter
Frequencylow high
Gai
n
+
-
Frequency Response Curve (FRC)
Frequencylow high
Gai
n
+
-
Center frequency
lower cutofffrequency
upper cutoff frequency
passband
3 dB
Operation of a filter on a signal
NOTE Amplitude spectrum describes a soundFrequency response curve describes a filter
Learning Objectivesbull Define resonance free and forced vibrationbull Describe how the pendulum and spring mass models can
help explain resonancebull Outline how mass and stiffness influences the resonant
frequency of a mass spring systembull Outline how acoustic resonators behave like acoustic filtersbull Calculate resonant frequencies of a uniform tube based on
its physical dimensionsbull Describe how the wavelength of the sound determines the
resonant frequency of tube
Free vibration
bull objects tend to vibrate at a characteristic or resonant frequency (RF)
Forced vibration
bull A vibrating system can force a nearby system into vibration
bull The efficiency with which this is accomplished is related to the similarity in the resonant frequency (RF) of the two systems
Forced vibration
bull If the RF of the two systems are the same the amplitude of forced vibration will be large
bull If the RF of the two systems are quite different the amplitude of forced vibration will be small or nonexistent
Resonance refers to
bull The tendency for an object to vibrate at a particular frequency or frequencies
bull The ability of a vibrating system to force another system into vibration
Back to the mass spring model
bull Vibratory frequency of the mass spring determined byndash Massndash Stiffness of the spring
httpphetcoloradoeduensimulationmass-spring-lab
Acoustic Resonance
bull Ideas from mechanical resonance also applies to acoustic systems
bull Acoustic chambers will transmit sound frequencies with more or less efficiency depending upon the physical characteristics
bull Therefore they act as filters passing through (and even amplifying) some frequencies and attentuating others
Acoustic Resonance
bull And since they act as filters they have most of the same features of a filter even though we might use different names
bull Center frequency is often termed the resonant frequency
bull Frequency response curve often termed the resonance curve
Helmholtz Resonator
Actions of a Helmholtz Resonator
Stephen M Tasko
Other Acoustic Resonators Tube Resonators
bull Uniform tubes Factors that influence resonancendash Lengthndash Cross-sectional area along its lengthndash Whether it is closed at either or both ends
Uniform tube closed at one end
Uniform tube closed at one end
Stephen M Tasko
Uniform tube closed at one end
First resonance or formant
F1 = c4lWhere
c=speed of sound (35000 cmsec)l = length of the tube
males ~ 175 cmfemales ~ 14 cm
Higher resonantformant frequencies are odd multiples of F1
For examplebull F1 = (c4l )1
bull F2 = (c4l )3
bull F3 = (c4l )5
Comparing Helmholtz and tube resonators
Resonator Features
Sharply tuned Broadly tuned
Resonator Features
An example of the resonance characteristics of the human vocal tract
Frequency
Gain
SPPA 4030 Speech Science
Topic 1 The Speech Chain
The Speech Chain (Denes amp Pinson 1993)
What information is embedded in the speech signal
Branches of science employed to understand speech communication
Physical Quantities Review An Independent Learning Activity
Assignment 1
Topic 2 The Source-Filter Theory of Speech Production An Intr
Producing Speech
Source-Filter Theory of Speech Production
Vocal tract is a tube that can vary its shape
Source Filter Theory
Same Source Different Filter
Different Source Same Filters
Different Source Same Filters (Human)
Different Source Same Filters (Human) (2)
Different Source Same Filters (Human) (3)
Different Source Same Filters (Human) (4)
Different Source Same Filters (Non-Human)
Different Source Same Filters (Non-Human) (2)
Different Source Same Filters (Non-Human) If it quacks like a
Source Filter Theory Applied Alaryngeal Speech
Source-Filter Theory Applied Esophageal Insufflation Test
Source-Filter Theory Applied Tracheoesophageal (TE) Speech
Source Filter Theory Applied The Talkbox
Source-Filter Theory Applied The Talkbox
Topic 3 A Brief Review of Physical Acoustics
Spring Mass Model
What is sound
Sound-conducting media
Model of air molecule vibration (Time 1)
Model of air molecule vibration (Time 2)
Model of air molecule vibration (Time 3)
Model of air molecule vibration (Time 4)
Model of air molecule vibration (Time 5)
Model of air molecule vibration
Wave action of molecular motion
Amplitude waveform
Amplitude waveform (2)
Where is pressure in this model
Pressure waveform
Measuring Sound
Measuring Sound Signal Amplitude
Measuring Sound Signal Amplitude (2)
What units do we use to measure signal amplitude
Brief Review The decibel scale
Absolute vs relative measurement
Typical reference values
Howeverhellip
Linear vs logarithmic
Linear vs logarithmic (2)
Logarithmic Scale
Logarithmic Scale (2)
Combining the idea of logarithmic and relativehellip
Intensity vs Pressure
Extending the formula to pressure
Measuring Sound Frequencyperiod
Measuring Sound Frequencyperiod (2)
Phase Uniform Circular Motion
Initiating a sound waves that differ only in phase
Spatial variation in pressure wave
Spatial variation in pressure wave
Spatial variation in pressure wave (2)
Relation between frequency and wavelength
Learning Objectives
Graphic representation of sound
Same sound different graphs
Classification of sounds
Simple periodic sound
Simple periodic sound Graphic appearance
Complex periodic sounds
Complex periodic sounds Graphic appearance
Complex periodic sounds Graphic appearance (2)
Glottal Source
Amplitude vs Phase Spectrum
Amplitude vs Phase Spectrum (2)
(Complex) Aperiodic sounds
Aperiodic sounds Graphic appearance
Aperiodic sounds Graphic appearance (2)
Analysis of complex waves
Learning Objectives (2)
The ldquoenveloperdquo of a sound wave
Waveform envelope
Waveform envelope (2)
Spectrum envelope
Thought Question
Amplitude Spectrum Window Size
ldquoInstantaneousrdquo Amplitude Spectra
(Long Term) Average Amplitude Spectrum
Slide 90
Learning Objectives (3)
The Spectrogram
Building a spectrogram
Building a spectrogram
Building a spectrogram (2)
Two main types of spectrograms
Wide vs Narrow Band Spectrograms
Learning Objectives (4)
What is an ldquoAcousticrdquo Filter
Why might we be interested in filters
Kinds of frequency selective filters
Low Pass Filters
High Pass Filters
Band Pass Filter
Frequency Response Curve (FRC)
Operation of a filter on a signal
Learning Objectives (5)
Free vibration
Forced vibration
Forced vibration (2)
Resonance refers to
Back to the mass spring model
Acoustic Resonance
Acoustic Resonance (2)
Helmholtz Resonator
Actions of a Helmholtz Resonator
Other Acoustic Resonators Tube Resonators
Uniform tube closed at one end
Uniform tube closed at one end (2)
Uniform tube closed at one end
Comparing Helmholtz and tube resonators
Slide 122
Slide 123
Aperiodic sounds Graphic appearance
From Hillenbrand
>
Analysis of complex wavesbull Waves can be summedbull Complex waves are the sum of simple wavesbull Fourier French Mathematician
ndash Any complex waveform may be formed by summing sinusoids of various frequency amplitude and phase
bull Fourier Analysisndash Provides a unique (only one) solution for a given sound signalndash Is reflected in the amplitude and phase spectrum of the signalndash Reveals the building blocks of complex waves which are sinusoids
Learning Objectives
bull Draw and differentiate the waveform and the waveform envelope
bull Draw and differentiate the amplitude spectrum the phase spectrum and the spectrum envelope
bull Differential between short-term spectra and long-term average spectra
The ldquoenveloperdquo of a sound wave
bull Waveform envelopendash imaginary smooth line that follows the peak of the
amplitude of a sound pressure waveformbull Spectrum envelopendash Imaginary smooth line drawn on top of the
amplitude spectrum
Waveform envelope
From Hillenbrand
Waveform envelope
Time
>
Spectrum envelope
Frequency
Ampl
itude
Thought Question
Can an aperiodic and complex periodic sound have identical
spectrum envelopes
Amplitude Spectrum Window Size
bull ldquoshort-termrdquo vs ldquolong-term averagerdquo amplitude spectrum
ldquoInstantaneousrdquo Amplitude Spectra
(Long Term) Average Amplitude Spectrum
Learning Objectivesbull Describe how the amplitude spectrum and the spectrogram are
relatedbull Identify the axis units of the spectrogrambull Provide some advantages of the spectrogram over the
amplitude spectrumbull Distinguish between a wide band and narrow band spectrogram
and outline the different information each providesbull Distinguish between a harmonic and a formant on a
spectrogrambull Be able to draw stylized (highly simplified) spectrograms based
on spectra and spectrum envelopes
The Spectrogram
Rotate90 degrees
F
AF
A
Building a spectrogram
Rotate it so thatThe amplitude isComing out of thepage
F
A This is really narrow because it is a slice in time
F
Time
Building a spectrogram
Dark bands= amplitudePeaks
Time
Freq
uenc
y
Building a spectrogram
Two main types of spectrograms
bull Narrow-band spectrogramsndash Akin to amplitude spectrums ldquolined uprdquondash Frequency resolution is really sharp
bull Wide-band spectrogramsndash Akin to spectrum envelopes ldquolined uprdquondash Frequency resolution not so sharp
Highlights harmonic structure
Highlights spectrum envelope
Wide vs Narrow Band Spectrograms
Learning Objectives
bull Define an acoustic filterbull Draw and label a frequency response curvebull Draw and differentiate different types of acoustic
filtersbull Define terms such as cutoff frequency center
frequency roll off rate gain and bandwidthbull Define and draw a basic filter system and relate that
to the source-filter theory of speech production
What is an ldquoAcousticrdquo Filter
bull holds back (attenuates) certain sounds and lets other sounds through - selective
Why might we be interested in filters
bull Human vocal tract acts like a frequency selective acoustic filter
bull Human auditory system behaves as a frequency selective filter
bull helps us understand how speech is produced and perceived
Kinds of frequency selective filters
Low-pass filtersndash Lets low frequencies ldquopass throughrdquo and attenuates high
frequencies
High-pass filtersndash Lets high frequencies ldquopass throughrdquo and attenuates low
frequencies
Band-pass filtersndash Lets a particular frequency range ldquopass throughrdquo and
attenuates other frequencies
Low Pass Filters
Frequencylow high
Gai
n
+
-
High Pass Filters
Frequencylow high
Gai
n
+
-
Band Pass Filter
Frequencylow high
Gai
n
+
-
Frequency Response Curve (FRC)
Frequencylow high
Gai
n
+
-
Center frequency
lower cutofffrequency
upper cutoff frequency
passband
3 dB
Operation of a filter on a signal
NOTE Amplitude spectrum describes a soundFrequency response curve describes a filter
Learning Objectivesbull Define resonance free and forced vibrationbull Describe how the pendulum and spring mass models can
help explain resonancebull Outline how mass and stiffness influences the resonant
frequency of a mass spring systembull Outline how acoustic resonators behave like acoustic filtersbull Calculate resonant frequencies of a uniform tube based on
its physical dimensionsbull Describe how the wavelength of the sound determines the
resonant frequency of tube
Free vibration
bull objects tend to vibrate at a characteristic or resonant frequency (RF)
Forced vibration
bull A vibrating system can force a nearby system into vibration
bull The efficiency with which this is accomplished is related to the similarity in the resonant frequency (RF) of the two systems
Forced vibration
bull If the RF of the two systems are the same the amplitude of forced vibration will be large
bull If the RF of the two systems are quite different the amplitude of forced vibration will be small or nonexistent
Resonance refers to
bull The tendency for an object to vibrate at a particular frequency or frequencies
bull The ability of a vibrating system to force another system into vibration
Back to the mass spring model
bull Vibratory frequency of the mass spring determined byndash Massndash Stiffness of the spring
httpphetcoloradoeduensimulationmass-spring-lab
Acoustic Resonance
bull Ideas from mechanical resonance also applies to acoustic systems
bull Acoustic chambers will transmit sound frequencies with more or less efficiency depending upon the physical characteristics
bull Therefore they act as filters passing through (and even amplifying) some frequencies and attentuating others
Acoustic Resonance
bull And since they act as filters they have most of the same features of a filter even though we might use different names
bull Center frequency is often termed the resonant frequency
bull Frequency response curve often termed the resonance curve
Helmholtz Resonator
Actions of a Helmholtz Resonator
Stephen M Tasko
Other Acoustic Resonators Tube Resonators
bull Uniform tubes Factors that influence resonancendash Lengthndash Cross-sectional area along its lengthndash Whether it is closed at either or both ends
Uniform tube closed at one end
Uniform tube closed at one end
Stephen M Tasko
Uniform tube closed at one end
First resonance or formant
F1 = c4lWhere
c=speed of sound (35000 cmsec)l = length of the tube
males ~ 175 cmfemales ~ 14 cm
Higher resonantformant frequencies are odd multiples of F1
For examplebull F1 = (c4l )1
bull F2 = (c4l )3
bull F3 = (c4l )5
Comparing Helmholtz and tube resonators
Resonator Features
Sharply tuned Broadly tuned
Resonator Features
An example of the resonance characteristics of the human vocal tract
Frequency
Gain
SPPA 4030 Speech Science
Topic 1 The Speech Chain
The Speech Chain (Denes amp Pinson 1993)
What information is embedded in the speech signal
Branches of science employed to understand speech communication
Physical Quantities Review An Independent Learning Activity
Assignment 1
Topic 2 The Source-Filter Theory of Speech Production An Intr
Producing Speech
Source-Filter Theory of Speech Production
Vocal tract is a tube that can vary its shape
Source Filter Theory
Same Source Different Filter
Different Source Same Filters
Different Source Same Filters (Human)
Different Source Same Filters (Human) (2)
Different Source Same Filters (Human) (3)
Different Source Same Filters (Human) (4)
Different Source Same Filters (Non-Human)
Different Source Same Filters (Non-Human) (2)
Different Source Same Filters (Non-Human) If it quacks like a
Source Filter Theory Applied Alaryngeal Speech
Source-Filter Theory Applied Esophageal Insufflation Test
Source-Filter Theory Applied Tracheoesophageal (TE) Speech
Source Filter Theory Applied The Talkbox
Source-Filter Theory Applied The Talkbox
Topic 3 A Brief Review of Physical Acoustics
Spring Mass Model
What is sound
Sound-conducting media
Model of air molecule vibration (Time 1)
Model of air molecule vibration (Time 2)
Model of air molecule vibration (Time 3)
Model of air molecule vibration (Time 4)
Model of air molecule vibration (Time 5)
Model of air molecule vibration
Wave action of molecular motion
Amplitude waveform
Amplitude waveform (2)
Where is pressure in this model
Pressure waveform
Measuring Sound
Measuring Sound Signal Amplitude
Measuring Sound Signal Amplitude (2)
What units do we use to measure signal amplitude
Brief Review The decibel scale
Absolute vs relative measurement
Typical reference values
Howeverhellip
Linear vs logarithmic
Linear vs logarithmic (2)
Logarithmic Scale
Logarithmic Scale (2)
Combining the idea of logarithmic and relativehellip
Intensity vs Pressure
Extending the formula to pressure
Measuring Sound Frequencyperiod
Measuring Sound Frequencyperiod (2)
Phase Uniform Circular Motion
Initiating a sound waves that differ only in phase
Spatial variation in pressure wave
Spatial variation in pressure wave
Spatial variation in pressure wave (2)
Relation between frequency and wavelength
Learning Objectives
Graphic representation of sound
Same sound different graphs
Classification of sounds
Simple periodic sound
Simple periodic sound Graphic appearance
Complex periodic sounds
Complex periodic sounds Graphic appearance
Complex periodic sounds Graphic appearance (2)
Glottal Source
Amplitude vs Phase Spectrum
Amplitude vs Phase Spectrum (2)
(Complex) Aperiodic sounds
Aperiodic sounds Graphic appearance
Aperiodic sounds Graphic appearance (2)
Analysis of complex waves
Learning Objectives (2)
The ldquoenveloperdquo of a sound wave
Waveform envelope
Waveform envelope (2)
Spectrum envelope
Thought Question
Amplitude Spectrum Window Size
ldquoInstantaneousrdquo Amplitude Spectra
(Long Term) Average Amplitude Spectrum
Slide 90
Learning Objectives (3)
The Spectrogram
Building a spectrogram
Building a spectrogram
Building a spectrogram (2)
Two main types of spectrograms
Wide vs Narrow Band Spectrograms
Learning Objectives (4)
What is an ldquoAcousticrdquo Filter
Why might we be interested in filters
Kinds of frequency selective filters
Low Pass Filters
High Pass Filters
Band Pass Filter
Frequency Response Curve (FRC)
Operation of a filter on a signal
Learning Objectives (5)
Free vibration
Forced vibration
Forced vibration (2)
Resonance refers to
Back to the mass spring model
Acoustic Resonance
Acoustic Resonance (2)
Helmholtz Resonator
Actions of a Helmholtz Resonator
Other Acoustic Resonators Tube Resonators
Uniform tube closed at one end
Uniform tube closed at one end (2)
Uniform tube closed at one end
Comparing Helmholtz and tube resonators
Slide 122
Slide 123
Analysis of complex wavesbull Waves can be summedbull Complex waves are the sum of simple wavesbull Fourier French Mathematician
ndash Any complex waveform may be formed by summing sinusoids of various frequency amplitude and phase
bull Fourier Analysisndash Provides a unique (only one) solution for a given sound signalndash Is reflected in the amplitude and phase spectrum of the signalndash Reveals the building blocks of complex waves which are sinusoids
Learning Objectives
bull Draw and differentiate the waveform and the waveform envelope
bull Draw and differentiate the amplitude spectrum the phase spectrum and the spectrum envelope
bull Differential between short-term spectra and long-term average spectra
The ldquoenveloperdquo of a sound wave
bull Waveform envelopendash imaginary smooth line that follows the peak of the
amplitude of a sound pressure waveformbull Spectrum envelopendash Imaginary smooth line drawn on top of the
amplitude spectrum
Waveform envelope
From Hillenbrand
Waveform envelope
Time
>
Spectrum envelope
Frequency
Ampl
itude
Thought Question
Can an aperiodic and complex periodic sound have identical
spectrum envelopes
Amplitude Spectrum Window Size
bull ldquoshort-termrdquo vs ldquolong-term averagerdquo amplitude spectrum
ldquoInstantaneousrdquo Amplitude Spectra
(Long Term) Average Amplitude Spectrum
Learning Objectivesbull Describe how the amplitude spectrum and the spectrogram are
relatedbull Identify the axis units of the spectrogrambull Provide some advantages of the spectrogram over the
amplitude spectrumbull Distinguish between a wide band and narrow band spectrogram
and outline the different information each providesbull Distinguish between a harmonic and a formant on a
spectrogrambull Be able to draw stylized (highly simplified) spectrograms based
on spectra and spectrum envelopes
The Spectrogram
Rotate90 degrees
F
AF
A
Building a spectrogram
Rotate it so thatThe amplitude isComing out of thepage
F
A This is really narrow because it is a slice in time
F
Time
Building a spectrogram
Dark bands= amplitudePeaks
Time
Freq
uenc
y
Building a spectrogram
Two main types of spectrograms
bull Narrow-band spectrogramsndash Akin to amplitude spectrums ldquolined uprdquondash Frequency resolution is really sharp
bull Wide-band spectrogramsndash Akin to spectrum envelopes ldquolined uprdquondash Frequency resolution not so sharp
Highlights harmonic structure
Highlights spectrum envelope
Wide vs Narrow Band Spectrograms
Learning Objectives
bull Define an acoustic filterbull Draw and label a frequency response curvebull Draw and differentiate different types of acoustic
filtersbull Define terms such as cutoff frequency center
frequency roll off rate gain and bandwidthbull Define and draw a basic filter system and relate that
to the source-filter theory of speech production
What is an ldquoAcousticrdquo Filter
bull holds back (attenuates) certain sounds and lets other sounds through - selective
Why might we be interested in filters
bull Human vocal tract acts like a frequency selective acoustic filter
bull Human auditory system behaves as a frequency selective filter
bull helps us understand how speech is produced and perceived
Kinds of frequency selective filters
Low-pass filtersndash Lets low frequencies ldquopass throughrdquo and attenuates high
frequencies
High-pass filtersndash Lets high frequencies ldquopass throughrdquo and attenuates low
frequencies
Band-pass filtersndash Lets a particular frequency range ldquopass throughrdquo and
attenuates other frequencies
Low Pass Filters
Frequencylow high
Gai
n
+
-
High Pass Filters
Frequencylow high
Gai
n
+
-
Band Pass Filter
Frequencylow high
Gai
n
+
-
Frequency Response Curve (FRC)
Frequencylow high
Gai
n
+
-
Center frequency
lower cutofffrequency
upper cutoff frequency
passband
3 dB
Operation of a filter on a signal
NOTE Amplitude spectrum describes a soundFrequency response curve describes a filter
Learning Objectivesbull Define resonance free and forced vibrationbull Describe how the pendulum and spring mass models can
help explain resonancebull Outline how mass and stiffness influences the resonant
frequency of a mass spring systembull Outline how acoustic resonators behave like acoustic filtersbull Calculate resonant frequencies of a uniform tube based on
its physical dimensionsbull Describe how the wavelength of the sound determines the
resonant frequency of tube
Free vibration
bull objects tend to vibrate at a characteristic or resonant frequency (RF)
Forced vibration
bull A vibrating system can force a nearby system into vibration
bull The efficiency with which this is accomplished is related to the similarity in the resonant frequency (RF) of the two systems
Forced vibration
bull If the RF of the two systems are the same the amplitude of forced vibration will be large
bull If the RF of the two systems are quite different the amplitude of forced vibration will be small or nonexistent
Resonance refers to
bull The tendency for an object to vibrate at a particular frequency or frequencies
bull The ability of a vibrating system to force another system into vibration
Back to the mass spring model
bull Vibratory frequency of the mass spring determined byndash Massndash Stiffness of the spring
httpphetcoloradoeduensimulationmass-spring-lab
Acoustic Resonance
bull Ideas from mechanical resonance also applies to acoustic systems
bull Acoustic chambers will transmit sound frequencies with more or less efficiency depending upon the physical characteristics
bull Therefore they act as filters passing through (and even amplifying) some frequencies and attentuating others
Acoustic Resonance
bull And since they act as filters they have most of the same features of a filter even though we might use different names
bull Center frequency is often termed the resonant frequency
bull Frequency response curve often termed the resonance curve
Helmholtz Resonator
Actions of a Helmholtz Resonator
Stephen M Tasko
Other Acoustic Resonators Tube Resonators
bull Uniform tubes Factors that influence resonancendash Lengthndash Cross-sectional area along its lengthndash Whether it is closed at either or both ends
Uniform tube closed at one end
Uniform tube closed at one end
Stephen M Tasko
Uniform tube closed at one end
First resonance or formant
F1 = c4lWhere
c=speed of sound (35000 cmsec)l = length of the tube
males ~ 175 cmfemales ~ 14 cm
Higher resonantformant frequencies are odd multiples of F1
For examplebull F1 = (c4l )1
bull F2 = (c4l )3
bull F3 = (c4l )5
Comparing Helmholtz and tube resonators
Resonator Features
Sharply tuned Broadly tuned
Resonator Features
An example of the resonance characteristics of the human vocal tract
Frequency
Gain
SPPA 4030 Speech Science
Topic 1 The Speech Chain
The Speech Chain (Denes amp Pinson 1993)
What information is embedded in the speech signal
Branches of science employed to understand speech communication
Physical Quantities Review An Independent Learning Activity
Assignment 1
Topic 2 The Source-Filter Theory of Speech Production An Intr
Producing Speech
Source-Filter Theory of Speech Production
Vocal tract is a tube that can vary its shape
Source Filter Theory
Same Source Different Filter
Different Source Same Filters
Different Source Same Filters (Human)
Different Source Same Filters (Human) (2)
Different Source Same Filters (Human) (3)
Different Source Same Filters (Human) (4)
Different Source Same Filters (Non-Human)
Different Source Same Filters (Non-Human) (2)
Different Source Same Filters (Non-Human) If it quacks like a
Source Filter Theory Applied Alaryngeal Speech
Source-Filter Theory Applied Esophageal Insufflation Test
Source-Filter Theory Applied Tracheoesophageal (TE) Speech
Source Filter Theory Applied The Talkbox
Source-Filter Theory Applied The Talkbox
Topic 3 A Brief Review of Physical Acoustics
Spring Mass Model
What is sound
Sound-conducting media
Model of air molecule vibration (Time 1)
Model of air molecule vibration (Time 2)
Model of air molecule vibration (Time 3)
Model of air molecule vibration (Time 4)
Model of air molecule vibration (Time 5)
Model of air molecule vibration
Wave action of molecular motion
Amplitude waveform
Amplitude waveform (2)
Where is pressure in this model
Pressure waveform
Measuring Sound
Measuring Sound Signal Amplitude
Measuring Sound Signal Amplitude (2)
What units do we use to measure signal amplitude
Brief Review The decibel scale
Absolute vs relative measurement
Typical reference values
Howeverhellip
Linear vs logarithmic
Linear vs logarithmic (2)
Logarithmic Scale
Logarithmic Scale (2)
Combining the idea of logarithmic and relativehellip
Intensity vs Pressure
Extending the formula to pressure
Measuring Sound Frequencyperiod
Measuring Sound Frequencyperiod (2)
Phase Uniform Circular Motion
Initiating a sound waves that differ only in phase
Spatial variation in pressure wave
Spatial variation in pressure wave
Spatial variation in pressure wave (2)
Relation between frequency and wavelength
Learning Objectives
Graphic representation of sound
Same sound different graphs
Classification of sounds
Simple periodic sound
Simple periodic sound Graphic appearance
Complex periodic sounds
Complex periodic sounds Graphic appearance
Complex periodic sounds Graphic appearance (2)
Glottal Source
Amplitude vs Phase Spectrum
Amplitude vs Phase Spectrum (2)
(Complex) Aperiodic sounds
Aperiodic sounds Graphic appearance
Aperiodic sounds Graphic appearance (2)
Analysis of complex waves
Learning Objectives (2)
The ldquoenveloperdquo of a sound wave
Waveform envelope
Waveform envelope (2)
Spectrum envelope
Thought Question
Amplitude Spectrum Window Size
ldquoInstantaneousrdquo Amplitude Spectra
(Long Term) Average Amplitude Spectrum
Slide 90
Learning Objectives (3)
The Spectrogram
Building a spectrogram
Building a spectrogram
Building a spectrogram (2)
Two main types of spectrograms
Wide vs Narrow Band Spectrograms
Learning Objectives (4)
What is an ldquoAcousticrdquo Filter
Why might we be interested in filters
Kinds of frequency selective filters
Low Pass Filters
High Pass Filters
Band Pass Filter
Frequency Response Curve (FRC)
Operation of a filter on a signal
Learning Objectives (5)
Free vibration
Forced vibration
Forced vibration (2)
Resonance refers to
Back to the mass spring model
Acoustic Resonance
Acoustic Resonance (2)
Helmholtz Resonator
Actions of a Helmholtz Resonator
Other Acoustic Resonators Tube Resonators
Uniform tube closed at one end
Uniform tube closed at one end (2)
Uniform tube closed at one end
Comparing Helmholtz and tube resonators
Slide 122
Slide 123
Learning Objectives
bull Draw and differentiate the waveform and the waveform envelope
bull Draw and differentiate the amplitude spectrum the phase spectrum and the spectrum envelope
bull Differential between short-term spectra and long-term average spectra
The ldquoenveloperdquo of a sound wave
bull Waveform envelopendash imaginary smooth line that follows the peak of the
amplitude of a sound pressure waveformbull Spectrum envelopendash Imaginary smooth line drawn on top of the
amplitude spectrum
Waveform envelope
From Hillenbrand
Waveform envelope
Time
>
Spectrum envelope
Frequency
Ampl
itude
Thought Question
Can an aperiodic and complex periodic sound have identical
spectrum envelopes
Amplitude Spectrum Window Size
bull ldquoshort-termrdquo vs ldquolong-term averagerdquo amplitude spectrum
ldquoInstantaneousrdquo Amplitude Spectra
(Long Term) Average Amplitude Spectrum
Learning Objectivesbull Describe how the amplitude spectrum and the spectrogram are
relatedbull Identify the axis units of the spectrogrambull Provide some advantages of the spectrogram over the
amplitude spectrumbull Distinguish between a wide band and narrow band spectrogram
and outline the different information each providesbull Distinguish between a harmonic and a formant on a
spectrogrambull Be able to draw stylized (highly simplified) spectrograms based
on spectra and spectrum envelopes
The Spectrogram
Rotate90 degrees
F
AF
A
Building a spectrogram
Rotate it so thatThe amplitude isComing out of thepage
F
A This is really narrow because it is a slice in time
F
Time
Building a spectrogram
Dark bands= amplitudePeaks
Time
Freq
uenc
y
Building a spectrogram
Two main types of spectrograms
bull Narrow-band spectrogramsndash Akin to amplitude spectrums ldquolined uprdquondash Frequency resolution is really sharp
bull Wide-band spectrogramsndash Akin to spectrum envelopes ldquolined uprdquondash Frequency resolution not so sharp
Highlights harmonic structure
Highlights spectrum envelope
Wide vs Narrow Band Spectrograms
Learning Objectives
bull Define an acoustic filterbull Draw and label a frequency response curvebull Draw and differentiate different types of acoustic
filtersbull Define terms such as cutoff frequency center
frequency roll off rate gain and bandwidthbull Define and draw a basic filter system and relate that
to the source-filter theory of speech production
What is an ldquoAcousticrdquo Filter
bull holds back (attenuates) certain sounds and lets other sounds through - selective
Why might we be interested in filters
bull Human vocal tract acts like a frequency selective acoustic filter
bull Human auditory system behaves as a frequency selective filter
bull helps us understand how speech is produced and perceived
Kinds of frequency selective filters
Low-pass filtersndash Lets low frequencies ldquopass throughrdquo and attenuates high
frequencies
High-pass filtersndash Lets high frequencies ldquopass throughrdquo and attenuates low
frequencies
Band-pass filtersndash Lets a particular frequency range ldquopass throughrdquo and
attenuates other frequencies
Low Pass Filters
Frequencylow high
Gai
n
+
-
High Pass Filters
Frequencylow high
Gai
n
+
-
Band Pass Filter
Frequencylow high
Gai
n
+
-
Frequency Response Curve (FRC)
Frequencylow high
Gai
n
+
-
Center frequency
lower cutofffrequency
upper cutoff frequency
passband
3 dB
Operation of a filter on a signal
NOTE Amplitude spectrum describes a soundFrequency response curve describes a filter
Learning Objectivesbull Define resonance free and forced vibrationbull Describe how the pendulum and spring mass models can
help explain resonancebull Outline how mass and stiffness influences the resonant
frequency of a mass spring systembull Outline how acoustic resonators behave like acoustic filtersbull Calculate resonant frequencies of a uniform tube based on
its physical dimensionsbull Describe how the wavelength of the sound determines the
resonant frequency of tube
Free vibration
bull objects tend to vibrate at a characteristic or resonant frequency (RF)
Forced vibration
bull A vibrating system can force a nearby system into vibration
bull The efficiency with which this is accomplished is related to the similarity in the resonant frequency (RF) of the two systems
Forced vibration
bull If the RF of the two systems are the same the amplitude of forced vibration will be large
bull If the RF of the two systems are quite different the amplitude of forced vibration will be small or nonexistent
Resonance refers to
bull The tendency for an object to vibrate at a particular frequency or frequencies
bull The ability of a vibrating system to force another system into vibration
Back to the mass spring model
bull Vibratory frequency of the mass spring determined byndash Massndash Stiffness of the spring
httpphetcoloradoeduensimulationmass-spring-lab
Acoustic Resonance
bull Ideas from mechanical resonance also applies to acoustic systems
bull Acoustic chambers will transmit sound frequencies with more or less efficiency depending upon the physical characteristics
bull Therefore they act as filters passing through (and even amplifying) some frequencies and attentuating others
Acoustic Resonance
bull And since they act as filters they have most of the same features of a filter even though we might use different names
bull Center frequency is often termed the resonant frequency
bull Frequency response curve often termed the resonance curve
Helmholtz Resonator
Actions of a Helmholtz Resonator
Stephen M Tasko
Other Acoustic Resonators Tube Resonators
bull Uniform tubes Factors that influence resonancendash Lengthndash Cross-sectional area along its lengthndash Whether it is closed at either or both ends
Uniform tube closed at one end
Uniform tube closed at one end
Stephen M Tasko
Uniform tube closed at one end
First resonance or formant
F1 = c4lWhere
c=speed of sound (35000 cmsec)l = length of the tube
males ~ 175 cmfemales ~ 14 cm
Higher resonantformant frequencies are odd multiples of F1
For examplebull F1 = (c4l )1
bull F2 = (c4l )3
bull F3 = (c4l )5
Comparing Helmholtz and tube resonators
Resonator Features
Sharply tuned Broadly tuned
Resonator Features
An example of the resonance characteristics of the human vocal tract
Frequency
Gain
SPPA 4030 Speech Science
Topic 1 The Speech Chain
The Speech Chain (Denes amp Pinson 1993)
What information is embedded in the speech signal
Branches of science employed to understand speech communication
Physical Quantities Review An Independent Learning Activity
Assignment 1
Topic 2 The Source-Filter Theory of Speech Production An Intr
Producing Speech
Source-Filter Theory of Speech Production
Vocal tract is a tube that can vary its shape
Source Filter Theory
Same Source Different Filter
Different Source Same Filters
Different Source Same Filters (Human)
Different Source Same Filters (Human) (2)
Different Source Same Filters (Human) (3)
Different Source Same Filters (Human) (4)
Different Source Same Filters (Non-Human)
Different Source Same Filters (Non-Human) (2)
Different Source Same Filters (Non-Human) If it quacks like a
Source Filter Theory Applied Alaryngeal Speech
Source-Filter Theory Applied Esophageal Insufflation Test
Source-Filter Theory Applied Tracheoesophageal (TE) Speech
Source Filter Theory Applied The Talkbox
Source-Filter Theory Applied The Talkbox
Topic 3 A Brief Review of Physical Acoustics
Spring Mass Model
What is sound
Sound-conducting media
Model of air molecule vibration (Time 1)
Model of air molecule vibration (Time 2)
Model of air molecule vibration (Time 3)
Model of air molecule vibration (Time 4)
Model of air molecule vibration (Time 5)
Model of air molecule vibration
Wave action of molecular motion
Amplitude waveform
Amplitude waveform (2)
Where is pressure in this model
Pressure waveform
Measuring Sound
Measuring Sound Signal Amplitude
Measuring Sound Signal Amplitude (2)
What units do we use to measure signal amplitude
Brief Review The decibel scale
Absolute vs relative measurement
Typical reference values
Howeverhellip
Linear vs logarithmic
Linear vs logarithmic (2)
Logarithmic Scale
Logarithmic Scale (2)
Combining the idea of logarithmic and relativehellip
Intensity vs Pressure
Extending the formula to pressure
Measuring Sound Frequencyperiod
Measuring Sound Frequencyperiod (2)
Phase Uniform Circular Motion
Initiating a sound waves that differ only in phase
Spatial variation in pressure wave
Spatial variation in pressure wave
Spatial variation in pressure wave (2)
Relation between frequency and wavelength
Learning Objectives
Graphic representation of sound
Same sound different graphs
Classification of sounds
Simple periodic sound
Simple periodic sound Graphic appearance
Complex periodic sounds
Complex periodic sounds Graphic appearance
Complex periodic sounds Graphic appearance (2)
Glottal Source
Amplitude vs Phase Spectrum
Amplitude vs Phase Spectrum (2)
(Complex) Aperiodic sounds
Aperiodic sounds Graphic appearance
Aperiodic sounds Graphic appearance (2)
Analysis of complex waves
Learning Objectives (2)
The ldquoenveloperdquo of a sound wave
Waveform envelope
Waveform envelope (2)
Spectrum envelope
Thought Question
Amplitude Spectrum Window Size
ldquoInstantaneousrdquo Amplitude Spectra
(Long Term) Average Amplitude Spectrum
Slide 90
Learning Objectives (3)
The Spectrogram
Building a spectrogram
Building a spectrogram
Building a spectrogram (2)
Two main types of spectrograms
Wide vs Narrow Band Spectrograms
Learning Objectives (4)
What is an ldquoAcousticrdquo Filter
Why might we be interested in filters
Kinds of frequency selective filters
Low Pass Filters
High Pass Filters
Band Pass Filter
Frequency Response Curve (FRC)
Operation of a filter on a signal
Learning Objectives (5)
Free vibration
Forced vibration
Forced vibration (2)
Resonance refers to
Back to the mass spring model
Acoustic Resonance
Acoustic Resonance (2)
Helmholtz Resonator
Actions of a Helmholtz Resonator
Other Acoustic Resonators Tube Resonators
Uniform tube closed at one end
Uniform tube closed at one end (2)
Uniform tube closed at one end
Comparing Helmholtz and tube resonators
Slide 122
Slide 123
The ldquoenveloperdquo of a sound wave
bull Waveform envelopendash imaginary smooth line that follows the peak of the
amplitude of a sound pressure waveformbull Spectrum envelopendash Imaginary smooth line drawn on top of the
amplitude spectrum
Waveform envelope
From Hillenbrand
Waveform envelope
Time
>
Spectrum envelope
Frequency
Ampl
itude
Thought Question
Can an aperiodic and complex periodic sound have identical
spectrum envelopes
Amplitude Spectrum Window Size
bull ldquoshort-termrdquo vs ldquolong-term averagerdquo amplitude spectrum
ldquoInstantaneousrdquo Amplitude Spectra
(Long Term) Average Amplitude Spectrum
Learning Objectivesbull Describe how the amplitude spectrum and the spectrogram are
relatedbull Identify the axis units of the spectrogrambull Provide some advantages of the spectrogram over the
amplitude spectrumbull Distinguish between a wide band and narrow band spectrogram
and outline the different information each providesbull Distinguish between a harmonic and a formant on a
spectrogrambull Be able to draw stylized (highly simplified) spectrograms based
on spectra and spectrum envelopes
The Spectrogram
Rotate90 degrees
F
AF
A
Building a spectrogram
Rotate it so thatThe amplitude isComing out of thepage
F
A This is really narrow because it is a slice in time
F
Time
Building a spectrogram
Dark bands= amplitudePeaks
Time
Freq
uenc
y
Building a spectrogram
Two main types of spectrograms
bull Narrow-band spectrogramsndash Akin to amplitude spectrums ldquolined uprdquondash Frequency resolution is really sharp
bull Wide-band spectrogramsndash Akin to spectrum envelopes ldquolined uprdquondash Frequency resolution not so sharp
Highlights harmonic structure
Highlights spectrum envelope
Wide vs Narrow Band Spectrograms
Learning Objectives
bull Define an acoustic filterbull Draw and label a frequency response curvebull Draw and differentiate different types of acoustic
filtersbull Define terms such as cutoff frequency center
frequency roll off rate gain and bandwidthbull Define and draw a basic filter system and relate that
to the source-filter theory of speech production
What is an ldquoAcousticrdquo Filter
bull holds back (attenuates) certain sounds and lets other sounds through - selective
Why might we be interested in filters
bull Human vocal tract acts like a frequency selective acoustic filter
bull Human auditory system behaves as a frequency selective filter
bull helps us understand how speech is produced and perceived
Kinds of frequency selective filters
Low-pass filtersndash Lets low frequencies ldquopass throughrdquo and attenuates high
frequencies
High-pass filtersndash Lets high frequencies ldquopass throughrdquo and attenuates low
frequencies
Band-pass filtersndash Lets a particular frequency range ldquopass throughrdquo and
attenuates other frequencies
Low Pass Filters
Frequencylow high
Gai
n
+
-
High Pass Filters
Frequencylow high
Gai
n
+
-
Band Pass Filter
Frequencylow high
Gai
n
+
-
Frequency Response Curve (FRC)
Frequencylow high
Gai
n
+
-
Center frequency
lower cutofffrequency
upper cutoff frequency
passband
3 dB
Operation of a filter on a signal
NOTE Amplitude spectrum describes a soundFrequency response curve describes a filter
Learning Objectivesbull Define resonance free and forced vibrationbull Describe how the pendulum and spring mass models can
help explain resonancebull Outline how mass and stiffness influences the resonant
frequency of a mass spring systembull Outline how acoustic resonators behave like acoustic filtersbull Calculate resonant frequencies of a uniform tube based on
its physical dimensionsbull Describe how the wavelength of the sound determines the
resonant frequency of tube
Free vibration
bull objects tend to vibrate at a characteristic or resonant frequency (RF)
Forced vibration
bull A vibrating system can force a nearby system into vibration
bull The efficiency with which this is accomplished is related to the similarity in the resonant frequency (RF) of the two systems
Forced vibration
bull If the RF of the two systems are the same the amplitude of forced vibration will be large
bull If the RF of the two systems are quite different the amplitude of forced vibration will be small or nonexistent
Resonance refers to
bull The tendency for an object to vibrate at a particular frequency or frequencies
bull The ability of a vibrating system to force another system into vibration
Back to the mass spring model
bull Vibratory frequency of the mass spring determined byndash Massndash Stiffness of the spring
httpphetcoloradoeduensimulationmass-spring-lab
Acoustic Resonance
bull Ideas from mechanical resonance also applies to acoustic systems
bull Acoustic chambers will transmit sound frequencies with more or less efficiency depending upon the physical characteristics
bull Therefore they act as filters passing through (and even amplifying) some frequencies and attentuating others
Acoustic Resonance
bull And since they act as filters they have most of the same features of a filter even though we might use different names
bull Center frequency is often termed the resonant frequency
bull Frequency response curve often termed the resonance curve
Helmholtz Resonator
Actions of a Helmholtz Resonator
Stephen M Tasko
Other Acoustic Resonators Tube Resonators
bull Uniform tubes Factors that influence resonancendash Lengthndash Cross-sectional area along its lengthndash Whether it is closed at either or both ends
Uniform tube closed at one end
Uniform tube closed at one end
Stephen M Tasko
Uniform tube closed at one end
First resonance or formant
F1 = c4lWhere
c=speed of sound (35000 cmsec)l = length of the tube
males ~ 175 cmfemales ~ 14 cm
Higher resonantformant frequencies are odd multiples of F1
For examplebull F1 = (c4l )1
bull F2 = (c4l )3
bull F3 = (c4l )5
Comparing Helmholtz and tube resonators
Resonator Features
Sharply tuned Broadly tuned
Resonator Features
An example of the resonance characteristics of the human vocal tract
Frequency
Gain
SPPA 4030 Speech Science
Topic 1 The Speech Chain
The Speech Chain (Denes amp Pinson 1993)
What information is embedded in the speech signal
Branches of science employed to understand speech communication
Physical Quantities Review An Independent Learning Activity
Assignment 1
Topic 2 The Source-Filter Theory of Speech Production An Intr
Producing Speech
Source-Filter Theory of Speech Production
Vocal tract is a tube that can vary its shape
Source Filter Theory
Same Source Different Filter
Different Source Same Filters
Different Source Same Filters (Human)
Different Source Same Filters (Human) (2)
Different Source Same Filters (Human) (3)
Different Source Same Filters (Human) (4)
Different Source Same Filters (Non-Human)
Different Source Same Filters (Non-Human) (2)
Different Source Same Filters (Non-Human) If it quacks like a
Source Filter Theory Applied Alaryngeal Speech
Source-Filter Theory Applied Esophageal Insufflation Test
Source-Filter Theory Applied Tracheoesophageal (TE) Speech
Source Filter Theory Applied The Talkbox
Source-Filter Theory Applied The Talkbox
Topic 3 A Brief Review of Physical Acoustics
Spring Mass Model
What is sound
Sound-conducting media
Model of air molecule vibration (Time 1)
Model of air molecule vibration (Time 2)
Model of air molecule vibration (Time 3)
Model of air molecule vibration (Time 4)
Model of air molecule vibration (Time 5)
Model of air molecule vibration
Wave action of molecular motion
Amplitude waveform
Amplitude waveform (2)
Where is pressure in this model
Pressure waveform
Measuring Sound
Measuring Sound Signal Amplitude
Measuring Sound Signal Amplitude (2)
What units do we use to measure signal amplitude
Brief Review The decibel scale
Absolute vs relative measurement
Typical reference values
Howeverhellip
Linear vs logarithmic
Linear vs logarithmic (2)
Logarithmic Scale
Logarithmic Scale (2)
Combining the idea of logarithmic and relativehellip
Intensity vs Pressure
Extending the formula to pressure
Measuring Sound Frequencyperiod
Measuring Sound Frequencyperiod (2)
Phase Uniform Circular Motion
Initiating a sound waves that differ only in phase
Spatial variation in pressure wave
Spatial variation in pressure wave
Spatial variation in pressure wave (2)
Relation between frequency and wavelength
Learning Objectives
Graphic representation of sound
Same sound different graphs
Classification of sounds
Simple periodic sound
Simple periodic sound Graphic appearance
Complex periodic sounds
Complex periodic sounds Graphic appearance
Complex periodic sounds Graphic appearance (2)
Glottal Source
Amplitude vs Phase Spectrum
Amplitude vs Phase Spectrum (2)
(Complex) Aperiodic sounds
Aperiodic sounds Graphic appearance
Aperiodic sounds Graphic appearance (2)
Analysis of complex waves
Learning Objectives (2)
The ldquoenveloperdquo of a sound wave
Waveform envelope
Waveform envelope (2)
Spectrum envelope
Thought Question
Amplitude Spectrum Window Size
ldquoInstantaneousrdquo Amplitude Spectra
(Long Term) Average Amplitude Spectrum
Slide 90
Learning Objectives (3)
The Spectrogram
Building a spectrogram
Building a spectrogram
Building a spectrogram (2)
Two main types of spectrograms
Wide vs Narrow Band Spectrograms
Learning Objectives (4)
What is an ldquoAcousticrdquo Filter
Why might we be interested in filters
Kinds of frequency selective filters
Low Pass Filters
High Pass Filters
Band Pass Filter
Frequency Response Curve (FRC)
Operation of a filter on a signal
Learning Objectives (5)
Free vibration
Forced vibration
Forced vibration (2)
Resonance refers to
Back to the mass spring model
Acoustic Resonance
Acoustic Resonance (2)
Helmholtz Resonator
Actions of a Helmholtz Resonator
Other Acoustic Resonators Tube Resonators
Uniform tube closed at one end
Uniform tube closed at one end (2)
Uniform tube closed at one end
Comparing Helmholtz and tube resonators
Slide 122
Slide 123
Waveform envelope
From Hillenbrand
Waveform envelope
Time
>
Spectrum envelope
Frequency
Ampl
itude
Thought Question
Can an aperiodic and complex periodic sound have identical
spectrum envelopes
Amplitude Spectrum Window Size
bull ldquoshort-termrdquo vs ldquolong-term averagerdquo amplitude spectrum
ldquoInstantaneousrdquo Amplitude Spectra
(Long Term) Average Amplitude Spectrum
Learning Objectivesbull Describe how the amplitude spectrum and the spectrogram are
relatedbull Identify the axis units of the spectrogrambull Provide some advantages of the spectrogram over the
amplitude spectrumbull Distinguish between a wide band and narrow band spectrogram
and outline the different information each providesbull Distinguish between a harmonic and a formant on a
spectrogrambull Be able to draw stylized (highly simplified) spectrograms based
on spectra and spectrum envelopes
The Spectrogram
Rotate90 degrees
F
AF
A
Building a spectrogram
Rotate it so thatThe amplitude isComing out of thepage
F
A This is really narrow because it is a slice in time
F
Time
Building a spectrogram
Dark bands= amplitudePeaks
Time
Freq
uenc
y
Building a spectrogram
Two main types of spectrograms
bull Narrow-band spectrogramsndash Akin to amplitude spectrums ldquolined uprdquondash Frequency resolution is really sharp
bull Wide-band spectrogramsndash Akin to spectrum envelopes ldquolined uprdquondash Frequency resolution not so sharp
Highlights harmonic structure
Highlights spectrum envelope
Wide vs Narrow Band Spectrograms
Learning Objectives
bull Define an acoustic filterbull Draw and label a frequency response curvebull Draw and differentiate different types of acoustic
filtersbull Define terms such as cutoff frequency center
frequency roll off rate gain and bandwidthbull Define and draw a basic filter system and relate that
to the source-filter theory of speech production
What is an ldquoAcousticrdquo Filter
bull holds back (attenuates) certain sounds and lets other sounds through - selective
Why might we be interested in filters
bull Human vocal tract acts like a frequency selective acoustic filter
bull Human auditory system behaves as a frequency selective filter
bull helps us understand how speech is produced and perceived
Kinds of frequency selective filters
Low-pass filtersndash Lets low frequencies ldquopass throughrdquo and attenuates high
frequencies
High-pass filtersndash Lets high frequencies ldquopass throughrdquo and attenuates low
frequencies
Band-pass filtersndash Lets a particular frequency range ldquopass throughrdquo and
attenuates other frequencies
Low Pass Filters
Frequencylow high
Gai
n
+
-
High Pass Filters
Frequencylow high
Gai
n
+
-
Band Pass Filter
Frequencylow high
Gai
n
+
-
Frequency Response Curve (FRC)
Frequencylow high
Gai
n
+
-
Center frequency
lower cutofffrequency
upper cutoff frequency
passband
3 dB
Operation of a filter on a signal
NOTE Amplitude spectrum describes a soundFrequency response curve describes a filter
Learning Objectivesbull Define resonance free and forced vibrationbull Describe how the pendulum and spring mass models can
help explain resonancebull Outline how mass and stiffness influences the resonant
frequency of a mass spring systembull Outline how acoustic resonators behave like acoustic filtersbull Calculate resonant frequencies of a uniform tube based on
its physical dimensionsbull Describe how the wavelength of the sound determines the
resonant frequency of tube
Free vibration
bull objects tend to vibrate at a characteristic or resonant frequency (RF)
Forced vibration
bull A vibrating system can force a nearby system into vibration
bull The efficiency with which this is accomplished is related to the similarity in the resonant frequency (RF) of the two systems
Forced vibration
bull If the RF of the two systems are the same the amplitude of forced vibration will be large
bull If the RF of the two systems are quite different the amplitude of forced vibration will be small or nonexistent
Resonance refers to
bull The tendency for an object to vibrate at a particular frequency or frequencies
bull The ability of a vibrating system to force another system into vibration
Back to the mass spring model
bull Vibratory frequency of the mass spring determined byndash Massndash Stiffness of the spring
httpphetcoloradoeduensimulationmass-spring-lab
Acoustic Resonance
bull Ideas from mechanical resonance also applies to acoustic systems
bull Acoustic chambers will transmit sound frequencies with more or less efficiency depending upon the physical characteristics
bull Therefore they act as filters passing through (and even amplifying) some frequencies and attentuating others
Acoustic Resonance
bull And since they act as filters they have most of the same features of a filter even though we might use different names
bull Center frequency is often termed the resonant frequency
bull Frequency response curve often termed the resonance curve
Helmholtz Resonator
Actions of a Helmholtz Resonator
Stephen M Tasko
Other Acoustic Resonators Tube Resonators
bull Uniform tubes Factors that influence resonancendash Lengthndash Cross-sectional area along its lengthndash Whether it is closed at either or both ends
Uniform tube closed at one end
Uniform tube closed at one end
Stephen M Tasko
Uniform tube closed at one end
First resonance or formant
F1 = c4lWhere
c=speed of sound (35000 cmsec)l = length of the tube
males ~ 175 cmfemales ~ 14 cm
Higher resonantformant frequencies are odd multiples of F1
For examplebull F1 = (c4l )1
bull F2 = (c4l )3
bull F3 = (c4l )5
Comparing Helmholtz and tube resonators
Resonator Features
Sharply tuned Broadly tuned
Resonator Features
An example of the resonance characteristics of the human vocal tract
Frequency
Gain
SPPA 4030 Speech Science
Topic 1 The Speech Chain
The Speech Chain (Denes amp Pinson 1993)
What information is embedded in the speech signal
Branches of science employed to understand speech communication
Physical Quantities Review An Independent Learning Activity
Assignment 1
Topic 2 The Source-Filter Theory of Speech Production An Intr
Producing Speech
Source-Filter Theory of Speech Production
Vocal tract is a tube that can vary its shape
Source Filter Theory
Same Source Different Filter
Different Source Same Filters
Different Source Same Filters (Human)
Different Source Same Filters (Human) (2)
Different Source Same Filters (Human) (3)
Different Source Same Filters (Human) (4)
Different Source Same Filters (Non-Human)
Different Source Same Filters (Non-Human) (2)
Different Source Same Filters (Non-Human) If it quacks like a
Source Filter Theory Applied Alaryngeal Speech
Source-Filter Theory Applied Esophageal Insufflation Test
Source-Filter Theory Applied Tracheoesophageal (TE) Speech
Source Filter Theory Applied The Talkbox
Source-Filter Theory Applied The Talkbox
Topic 3 A Brief Review of Physical Acoustics
Spring Mass Model
What is sound
Sound-conducting media
Model of air molecule vibration (Time 1)
Model of air molecule vibration (Time 2)
Model of air molecule vibration (Time 3)
Model of air molecule vibration (Time 4)
Model of air molecule vibration (Time 5)
Model of air molecule vibration
Wave action of molecular motion
Amplitude waveform
Amplitude waveform (2)
Where is pressure in this model
Pressure waveform
Measuring Sound
Measuring Sound Signal Amplitude
Measuring Sound Signal Amplitude (2)
What units do we use to measure signal amplitude
Brief Review The decibel scale
Absolute vs relative measurement
Typical reference values
Howeverhellip
Linear vs logarithmic
Linear vs logarithmic (2)
Logarithmic Scale
Logarithmic Scale (2)
Combining the idea of logarithmic and relativehellip
Intensity vs Pressure
Extending the formula to pressure
Measuring Sound Frequencyperiod
Measuring Sound Frequencyperiod (2)
Phase Uniform Circular Motion
Initiating a sound waves that differ only in phase
Spatial variation in pressure wave
Spatial variation in pressure wave
Spatial variation in pressure wave (2)
Relation between frequency and wavelength
Learning Objectives
Graphic representation of sound
Same sound different graphs
Classification of sounds
Simple periodic sound
Simple periodic sound Graphic appearance
Complex periodic sounds
Complex periodic sounds Graphic appearance
Complex periodic sounds Graphic appearance (2)
Glottal Source
Amplitude vs Phase Spectrum
Amplitude vs Phase Spectrum (2)
(Complex) Aperiodic sounds
Aperiodic sounds Graphic appearance
Aperiodic sounds Graphic appearance (2)
Analysis of complex waves
Learning Objectives (2)
The ldquoenveloperdquo of a sound wave
Waveform envelope
Waveform envelope (2)
Spectrum envelope
Thought Question
Amplitude Spectrum Window Size
ldquoInstantaneousrdquo Amplitude Spectra
(Long Term) Average Amplitude Spectrum
Slide 90
Learning Objectives (3)
The Spectrogram
Building a spectrogram
Building a spectrogram
Building a spectrogram (2)
Two main types of spectrograms
Wide vs Narrow Band Spectrograms
Learning Objectives (4)
What is an ldquoAcousticrdquo Filter
Why might we be interested in filters
Kinds of frequency selective filters
Low Pass Filters
High Pass Filters
Band Pass Filter
Frequency Response Curve (FRC)
Operation of a filter on a signal
Learning Objectives (5)
Free vibration
Forced vibration
Forced vibration (2)
Resonance refers to
Back to the mass spring model
Acoustic Resonance
Acoustic Resonance (2)
Helmholtz Resonator
Actions of a Helmholtz Resonator
Other Acoustic Resonators Tube Resonators
Uniform tube closed at one end
Uniform tube closed at one end (2)
Uniform tube closed at one end
Comparing Helmholtz and tube resonators
Slide 122
Slide 123
Waveform envelope
Time
>
Spectrum envelope
Frequency
Ampl
itude
Thought Question
Can an aperiodic and complex periodic sound have identical
spectrum envelopes
Amplitude Spectrum Window Size
bull ldquoshort-termrdquo vs ldquolong-term averagerdquo amplitude spectrum
ldquoInstantaneousrdquo Amplitude Spectra
(Long Term) Average Amplitude Spectrum
Learning Objectivesbull Describe how the amplitude spectrum and the spectrogram are
relatedbull Identify the axis units of the spectrogrambull Provide some advantages of the spectrogram over the
amplitude spectrumbull Distinguish between a wide band and narrow band spectrogram
and outline the different information each providesbull Distinguish between a harmonic and a formant on a
spectrogrambull Be able to draw stylized (highly simplified) spectrograms based
on spectra and spectrum envelopes
The Spectrogram
Rotate90 degrees
F
AF
A
Building a spectrogram
Rotate it so thatThe amplitude isComing out of thepage
F
A This is really narrow because it is a slice in time
F
Time
Building a spectrogram
Dark bands= amplitudePeaks
Time
Freq
uenc
y
Building a spectrogram
Two main types of spectrograms
bull Narrow-band spectrogramsndash Akin to amplitude spectrums ldquolined uprdquondash Frequency resolution is really sharp
bull Wide-band spectrogramsndash Akin to spectrum envelopes ldquolined uprdquondash Frequency resolution not so sharp
Highlights harmonic structure
Highlights spectrum envelope
Wide vs Narrow Band Spectrograms
Learning Objectives
bull Define an acoustic filterbull Draw and label a frequency response curvebull Draw and differentiate different types of acoustic
filtersbull Define terms such as cutoff frequency center
frequency roll off rate gain and bandwidthbull Define and draw a basic filter system and relate that
to the source-filter theory of speech production
What is an ldquoAcousticrdquo Filter
bull holds back (attenuates) certain sounds and lets other sounds through - selective
Why might we be interested in filters
bull Human vocal tract acts like a frequency selective acoustic filter
bull Human auditory system behaves as a frequency selective filter
bull helps us understand how speech is produced and perceived
Kinds of frequency selective filters
Low-pass filtersndash Lets low frequencies ldquopass throughrdquo and attenuates high
frequencies
High-pass filtersndash Lets high frequencies ldquopass throughrdquo and attenuates low
frequencies
Band-pass filtersndash Lets a particular frequency range ldquopass throughrdquo and
attenuates other frequencies
Low Pass Filters
Frequencylow high
Gai
n
+
-
High Pass Filters
Frequencylow high
Gai
n
+
-
Band Pass Filter
Frequencylow high
Gai
n
+
-
Frequency Response Curve (FRC)
Frequencylow high
Gai
n
+
-
Center frequency
lower cutofffrequency
upper cutoff frequency
passband
3 dB
Operation of a filter on a signal
NOTE Amplitude spectrum describes a soundFrequency response curve describes a filter
Learning Objectivesbull Define resonance free and forced vibrationbull Describe how the pendulum and spring mass models can
help explain resonancebull Outline how mass and stiffness influences the resonant
frequency of a mass spring systembull Outline how acoustic resonators behave like acoustic filtersbull Calculate resonant frequencies of a uniform tube based on
its physical dimensionsbull Describe how the wavelength of the sound determines the
resonant frequency of tube
Free vibration
bull objects tend to vibrate at a characteristic or resonant frequency (RF)
Forced vibration
bull A vibrating system can force a nearby system into vibration
bull The efficiency with which this is accomplished is related to the similarity in the resonant frequency (RF) of the two systems
Forced vibration
bull If the RF of the two systems are the same the amplitude of forced vibration will be large
bull If the RF of the two systems are quite different the amplitude of forced vibration will be small or nonexistent
Resonance refers to
bull The tendency for an object to vibrate at a particular frequency or frequencies
bull The ability of a vibrating system to force another system into vibration
Back to the mass spring model
bull Vibratory frequency of the mass spring determined byndash Massndash Stiffness of the spring
httpphetcoloradoeduensimulationmass-spring-lab
Acoustic Resonance
bull Ideas from mechanical resonance also applies to acoustic systems
bull Acoustic chambers will transmit sound frequencies with more or less efficiency depending upon the physical characteristics
bull Therefore they act as filters passing through (and even amplifying) some frequencies and attentuating others
Acoustic Resonance
bull And since they act as filters they have most of the same features of a filter even though we might use different names
bull Center frequency is often termed the resonant frequency
bull Frequency response curve often termed the resonance curve
Helmholtz Resonator
Actions of a Helmholtz Resonator
Stephen M Tasko
Other Acoustic Resonators Tube Resonators
bull Uniform tubes Factors that influence resonancendash Lengthndash Cross-sectional area along its lengthndash Whether it is closed at either or both ends
Uniform tube closed at one end
Uniform tube closed at one end
Stephen M Tasko
Uniform tube closed at one end
First resonance or formant
F1 = c4lWhere
c=speed of sound (35000 cmsec)l = length of the tube
males ~ 175 cmfemales ~ 14 cm
Higher resonantformant frequencies are odd multiples of F1
For examplebull F1 = (c4l )1
bull F2 = (c4l )3
bull F3 = (c4l )5
Comparing Helmholtz and tube resonators
Resonator Features
Sharply tuned Broadly tuned
Resonator Features
An example of the resonance characteristics of the human vocal tract
Frequency
Gain
SPPA 4030 Speech Science
Topic 1 The Speech Chain
The Speech Chain (Denes amp Pinson 1993)
What information is embedded in the speech signal
Branches of science employed to understand speech communication
Physical Quantities Review An Independent Learning Activity
Assignment 1
Topic 2 The Source-Filter Theory of Speech Production An Intr
Producing Speech
Source-Filter Theory of Speech Production
Vocal tract is a tube that can vary its shape
Source Filter Theory
Same Source Different Filter
Different Source Same Filters
Different Source Same Filters (Human)
Different Source Same Filters (Human) (2)
Different Source Same Filters (Human) (3)
Different Source Same Filters (Human) (4)
Different Source Same Filters (Non-Human)
Different Source Same Filters (Non-Human) (2)
Different Source Same Filters (Non-Human) If it quacks like a
Source Filter Theory Applied Alaryngeal Speech
Source-Filter Theory Applied Esophageal Insufflation Test
Source-Filter Theory Applied Tracheoesophageal (TE) Speech
Source Filter Theory Applied The Talkbox
Source-Filter Theory Applied The Talkbox
Topic 3 A Brief Review of Physical Acoustics
Spring Mass Model
What is sound
Sound-conducting media
Model of air molecule vibration (Time 1)
Model of air molecule vibration (Time 2)
Model of air molecule vibration (Time 3)
Model of air molecule vibration (Time 4)
Model of air molecule vibration (Time 5)
Model of air molecule vibration
Wave action of molecular motion
Amplitude waveform
Amplitude waveform (2)
Where is pressure in this model
Pressure waveform
Measuring Sound
Measuring Sound Signal Amplitude
Measuring Sound Signal Amplitude (2)
What units do we use to measure signal amplitude
Brief Review The decibel scale
Absolute vs relative measurement
Typical reference values
Howeverhellip
Linear vs logarithmic
Linear vs logarithmic (2)
Logarithmic Scale
Logarithmic Scale (2)
Combining the idea of logarithmic and relativehellip
Intensity vs Pressure
Extending the formula to pressure
Measuring Sound Frequencyperiod
Measuring Sound Frequencyperiod (2)
Phase Uniform Circular Motion
Initiating a sound waves that differ only in phase
Spatial variation in pressure wave
Spatial variation in pressure wave
Spatial variation in pressure wave (2)
Relation between frequency and wavelength
Learning Objectives
Graphic representation of sound
Same sound different graphs
Classification of sounds
Simple periodic sound
Simple periodic sound Graphic appearance
Complex periodic sounds
Complex periodic sounds Graphic appearance
Complex periodic sounds Graphic appearance (2)
Glottal Source
Amplitude vs Phase Spectrum
Amplitude vs Phase Spectrum (2)
(Complex) Aperiodic sounds
Aperiodic sounds Graphic appearance
Aperiodic sounds Graphic appearance (2)
Analysis of complex waves
Learning Objectives (2)
The ldquoenveloperdquo of a sound wave
Waveform envelope
Waveform envelope (2)
Spectrum envelope
Thought Question
Amplitude Spectrum Window Size
ldquoInstantaneousrdquo Amplitude Spectra
(Long Term) Average Amplitude Spectrum
Slide 90
Learning Objectives (3)
The Spectrogram
Building a spectrogram
Building a spectrogram
Building a spectrogram (2)
Two main types of spectrograms
Wide vs Narrow Band Spectrograms
Learning Objectives (4)
What is an ldquoAcousticrdquo Filter
Why might we be interested in filters
Kinds of frequency selective filters
Low Pass Filters
High Pass Filters
Band Pass Filter
Frequency Response Curve (FRC)
Operation of a filter on a signal
Learning Objectives (5)
Free vibration
Forced vibration
Forced vibration (2)
Resonance refers to
Back to the mass spring model
Acoustic Resonance
Acoustic Resonance (2)
Helmholtz Resonator
Actions of a Helmholtz Resonator
Other Acoustic Resonators Tube Resonators
Uniform tube closed at one end
Uniform tube closed at one end (2)
Uniform tube closed at one end
Comparing Helmholtz and tube resonators
Slide 122
Slide 123
Spectrum envelope
Frequency
Ampl
itude
Thought Question
Can an aperiodic and complex periodic sound have identical
spectrum envelopes
Amplitude Spectrum Window Size
bull ldquoshort-termrdquo vs ldquolong-term averagerdquo amplitude spectrum
ldquoInstantaneousrdquo Amplitude Spectra
(Long Term) Average Amplitude Spectrum
Learning Objectivesbull Describe how the amplitude spectrum and the spectrogram are
relatedbull Identify the axis units of the spectrogrambull Provide some advantages of the spectrogram over the
amplitude spectrumbull Distinguish between a wide band and narrow band spectrogram
and outline the different information each providesbull Distinguish between a harmonic and a formant on a
spectrogrambull Be able to draw stylized (highly simplified) spectrograms based
on spectra and spectrum envelopes
The Spectrogram
Rotate90 degrees
F
AF
A
Building a spectrogram
Rotate it so thatThe amplitude isComing out of thepage
F
A This is really narrow because it is a slice in time
F
Time
Building a spectrogram
Dark bands= amplitudePeaks
Time
Freq
uenc
y
Building a spectrogram
Two main types of spectrograms
bull Narrow-band spectrogramsndash Akin to amplitude spectrums ldquolined uprdquondash Frequency resolution is really sharp
bull Wide-band spectrogramsndash Akin to spectrum envelopes ldquolined uprdquondash Frequency resolution not so sharp
Highlights harmonic structure
Highlights spectrum envelope
Wide vs Narrow Band Spectrograms
Learning Objectives
bull Define an acoustic filterbull Draw and label a frequency response curvebull Draw and differentiate different types of acoustic
filtersbull Define terms such as cutoff frequency center
frequency roll off rate gain and bandwidthbull Define and draw a basic filter system and relate that
to the source-filter theory of speech production
What is an ldquoAcousticrdquo Filter
bull holds back (attenuates) certain sounds and lets other sounds through - selective
Why might we be interested in filters
bull Human vocal tract acts like a frequency selective acoustic filter
bull Human auditory system behaves as a frequency selective filter
bull helps us understand how speech is produced and perceived
Kinds of frequency selective filters
Low-pass filtersndash Lets low frequencies ldquopass throughrdquo and attenuates high
frequencies
High-pass filtersndash Lets high frequencies ldquopass throughrdquo and attenuates low
frequencies
Band-pass filtersndash Lets a particular frequency range ldquopass throughrdquo and
attenuates other frequencies
Low Pass Filters
Frequencylow high
Gai
n
+
-
High Pass Filters
Frequencylow high
Gai
n
+
-
Band Pass Filter
Frequencylow high
Gai
n
+
-
Frequency Response Curve (FRC)
Frequencylow high
Gai
n
+
-
Center frequency
lower cutofffrequency
upper cutoff frequency
passband
3 dB
Operation of a filter on a signal
NOTE Amplitude spectrum describes a soundFrequency response curve describes a filter
Learning Objectivesbull Define resonance free and forced vibrationbull Describe how the pendulum and spring mass models can
help explain resonancebull Outline how mass and stiffness influences the resonant
frequency of a mass spring systembull Outline how acoustic resonators behave like acoustic filtersbull Calculate resonant frequencies of a uniform tube based on
its physical dimensionsbull Describe how the wavelength of the sound determines the
resonant frequency of tube
Free vibration
bull objects tend to vibrate at a characteristic or resonant frequency (RF)
Forced vibration
bull A vibrating system can force a nearby system into vibration
bull The efficiency with which this is accomplished is related to the similarity in the resonant frequency (RF) of the two systems
Forced vibration
bull If the RF of the two systems are the same the amplitude of forced vibration will be large
bull If the RF of the two systems are quite different the amplitude of forced vibration will be small or nonexistent
Resonance refers to
bull The tendency for an object to vibrate at a particular frequency or frequencies
bull The ability of a vibrating system to force another system into vibration
Back to the mass spring model
bull Vibratory frequency of the mass spring determined byndash Massndash Stiffness of the spring
httpphetcoloradoeduensimulationmass-spring-lab
Acoustic Resonance
bull Ideas from mechanical resonance also applies to acoustic systems
bull Acoustic chambers will transmit sound frequencies with more or less efficiency depending upon the physical characteristics
bull Therefore they act as filters passing through (and even amplifying) some frequencies and attentuating others
Acoustic Resonance
bull And since they act as filters they have most of the same features of a filter even though we might use different names
bull Center frequency is often termed the resonant frequency
bull Frequency response curve often termed the resonance curve
Helmholtz Resonator
Actions of a Helmholtz Resonator
Stephen M Tasko
Other Acoustic Resonators Tube Resonators
bull Uniform tubes Factors that influence resonancendash Lengthndash Cross-sectional area along its lengthndash Whether it is closed at either or both ends
Uniform tube closed at one end
Uniform tube closed at one end
Stephen M Tasko
Uniform tube closed at one end
First resonance or formant
F1 = c4lWhere
c=speed of sound (35000 cmsec)l = length of the tube
males ~ 175 cmfemales ~ 14 cm
Higher resonantformant frequencies are odd multiples of F1
For examplebull F1 = (c4l )1
bull F2 = (c4l )3
bull F3 = (c4l )5
Comparing Helmholtz and tube resonators
Resonator Features
Sharply tuned Broadly tuned
Resonator Features
An example of the resonance characteristics of the human vocal tract
Frequency
Gain
SPPA 4030 Speech Science
Topic 1 The Speech Chain
The Speech Chain (Denes amp Pinson 1993)
What information is embedded in the speech signal
Branches of science employed to understand speech communication
Physical Quantities Review An Independent Learning Activity
Assignment 1
Topic 2 The Source-Filter Theory of Speech Production An Intr
Producing Speech
Source-Filter Theory of Speech Production
Vocal tract is a tube that can vary its shape
Source Filter Theory
Same Source Different Filter
Different Source Same Filters
Different Source Same Filters (Human)
Different Source Same Filters (Human) (2)
Different Source Same Filters (Human) (3)
Different Source Same Filters (Human) (4)
Different Source Same Filters (Non-Human)
Different Source Same Filters (Non-Human) (2)
Different Source Same Filters (Non-Human) If it quacks like a
Source Filter Theory Applied Alaryngeal Speech
Source-Filter Theory Applied Esophageal Insufflation Test
Source-Filter Theory Applied Tracheoesophageal (TE) Speech
Source Filter Theory Applied The Talkbox
Source-Filter Theory Applied The Talkbox
Topic 3 A Brief Review of Physical Acoustics
Spring Mass Model
What is sound
Sound-conducting media
Model of air molecule vibration (Time 1)
Model of air molecule vibration (Time 2)
Model of air molecule vibration (Time 3)
Model of air molecule vibration (Time 4)
Model of air molecule vibration (Time 5)
Model of air molecule vibration
Wave action of molecular motion
Amplitude waveform
Amplitude waveform (2)
Where is pressure in this model
Pressure waveform
Measuring Sound
Measuring Sound Signal Amplitude
Measuring Sound Signal Amplitude (2)
What units do we use to measure signal amplitude
Brief Review The decibel scale
Absolute vs relative measurement
Typical reference values
Howeverhellip
Linear vs logarithmic
Linear vs logarithmic (2)
Logarithmic Scale
Logarithmic Scale (2)
Combining the idea of logarithmic and relativehellip
Intensity vs Pressure
Extending the formula to pressure
Measuring Sound Frequencyperiod
Measuring Sound Frequencyperiod (2)
Phase Uniform Circular Motion
Initiating a sound waves that differ only in phase
Spatial variation in pressure wave
Spatial variation in pressure wave
Spatial variation in pressure wave (2)
Relation between frequency and wavelength
Learning Objectives
Graphic representation of sound
Same sound different graphs
Classification of sounds
Simple periodic sound
Simple periodic sound Graphic appearance
Complex periodic sounds
Complex periodic sounds Graphic appearance
Complex periodic sounds Graphic appearance (2)
Glottal Source
Amplitude vs Phase Spectrum
Amplitude vs Phase Spectrum (2)
(Complex) Aperiodic sounds
Aperiodic sounds Graphic appearance
Aperiodic sounds Graphic appearance (2)
Analysis of complex waves
Learning Objectives (2)
The ldquoenveloperdquo of a sound wave
Waveform envelope
Waveform envelope (2)
Spectrum envelope
Thought Question
Amplitude Spectrum Window Size
ldquoInstantaneousrdquo Amplitude Spectra
(Long Term) Average Amplitude Spectrum
Slide 90
Learning Objectives (3)
The Spectrogram
Building a spectrogram
Building a spectrogram
Building a spectrogram (2)
Two main types of spectrograms
Wide vs Narrow Band Spectrograms
Learning Objectives (4)
What is an ldquoAcousticrdquo Filter
Why might we be interested in filters
Kinds of frequency selective filters
Low Pass Filters
High Pass Filters
Band Pass Filter
Frequency Response Curve (FRC)
Operation of a filter on a signal
Learning Objectives (5)
Free vibration
Forced vibration
Forced vibration (2)
Resonance refers to
Back to the mass spring model
Acoustic Resonance
Acoustic Resonance (2)
Helmholtz Resonator
Actions of a Helmholtz Resonator
Other Acoustic Resonators Tube Resonators
Uniform tube closed at one end
Uniform tube closed at one end (2)
Uniform tube closed at one end
Comparing Helmholtz and tube resonators
Slide 122
Slide 123
Thought Question
Can an aperiodic and complex periodic sound have identical
spectrum envelopes
Amplitude Spectrum Window Size
bull ldquoshort-termrdquo vs ldquolong-term averagerdquo amplitude spectrum
ldquoInstantaneousrdquo Amplitude Spectra
(Long Term) Average Amplitude Spectrum
Learning Objectivesbull Describe how the amplitude spectrum and the spectrogram are
relatedbull Identify the axis units of the spectrogrambull Provide some advantages of the spectrogram over the
amplitude spectrumbull Distinguish between a wide band and narrow band spectrogram
and outline the different information each providesbull Distinguish between a harmonic and a formant on a
spectrogrambull Be able to draw stylized (highly simplified) spectrograms based
on spectra and spectrum envelopes
The Spectrogram
Rotate90 degrees
F
AF
A
Building a spectrogram
Rotate it so thatThe amplitude isComing out of thepage
F
A This is really narrow because it is a slice in time
F
Time
Building a spectrogram
Dark bands= amplitudePeaks
Time
Freq
uenc
y
Building a spectrogram
Two main types of spectrograms
bull Narrow-band spectrogramsndash Akin to amplitude spectrums ldquolined uprdquondash Frequency resolution is really sharp
bull Wide-band spectrogramsndash Akin to spectrum envelopes ldquolined uprdquondash Frequency resolution not so sharp
Highlights harmonic structure
Highlights spectrum envelope
Wide vs Narrow Band Spectrograms
Learning Objectives
bull Define an acoustic filterbull Draw and label a frequency response curvebull Draw and differentiate different types of acoustic
filtersbull Define terms such as cutoff frequency center
frequency roll off rate gain and bandwidthbull Define and draw a basic filter system and relate that
to the source-filter theory of speech production
What is an ldquoAcousticrdquo Filter
bull holds back (attenuates) certain sounds and lets other sounds through - selective
Why might we be interested in filters
bull Human vocal tract acts like a frequency selective acoustic filter
bull Human auditory system behaves as a frequency selective filter
bull helps us understand how speech is produced and perceived
Kinds of frequency selective filters
Low-pass filtersndash Lets low frequencies ldquopass throughrdquo and attenuates high
frequencies
High-pass filtersndash Lets high frequencies ldquopass throughrdquo and attenuates low
frequencies
Band-pass filtersndash Lets a particular frequency range ldquopass throughrdquo and
attenuates other frequencies
Low Pass Filters
Frequencylow high
Gai
n
+
-
High Pass Filters
Frequencylow high
Gai
n
+
-
Band Pass Filter
Frequencylow high
Gai
n
+
-
Frequency Response Curve (FRC)
Frequencylow high
Gai
n
+
-
Center frequency
lower cutofffrequency
upper cutoff frequency
passband
3 dB
Operation of a filter on a signal
NOTE Amplitude spectrum describes a soundFrequency response curve describes a filter
Learning Objectivesbull Define resonance free and forced vibrationbull Describe how the pendulum and spring mass models can
help explain resonancebull Outline how mass and stiffness influences the resonant
frequency of a mass spring systembull Outline how acoustic resonators behave like acoustic filtersbull Calculate resonant frequencies of a uniform tube based on
its physical dimensionsbull Describe how the wavelength of the sound determines the
resonant frequency of tube
Free vibration
bull objects tend to vibrate at a characteristic or resonant frequency (RF)
Forced vibration
bull A vibrating system can force a nearby system into vibration
bull The efficiency with which this is accomplished is related to the similarity in the resonant frequency (RF) of the two systems
Forced vibration
bull If the RF of the two systems are the same the amplitude of forced vibration will be large
bull If the RF of the two systems are quite different the amplitude of forced vibration will be small or nonexistent
Resonance refers to
bull The tendency for an object to vibrate at a particular frequency or frequencies
bull The ability of a vibrating system to force another system into vibration
Back to the mass spring model
bull Vibratory frequency of the mass spring determined byndash Massndash Stiffness of the spring
httpphetcoloradoeduensimulationmass-spring-lab
Acoustic Resonance
bull Ideas from mechanical resonance also applies to acoustic systems
bull Acoustic chambers will transmit sound frequencies with more or less efficiency depending upon the physical characteristics
bull Therefore they act as filters passing through (and even amplifying) some frequencies and attentuating others
Acoustic Resonance
bull And since they act as filters they have most of the same features of a filter even though we might use different names
bull Center frequency is often termed the resonant frequency
bull Frequency response curve often termed the resonance curve
Helmholtz Resonator
Actions of a Helmholtz Resonator
Stephen M Tasko
Other Acoustic Resonators Tube Resonators
bull Uniform tubes Factors that influence resonancendash Lengthndash Cross-sectional area along its lengthndash Whether it is closed at either or both ends
Uniform tube closed at one end
Uniform tube closed at one end
Stephen M Tasko
Uniform tube closed at one end
First resonance or formant
F1 = c4lWhere
c=speed of sound (35000 cmsec)l = length of the tube
males ~ 175 cmfemales ~ 14 cm
Higher resonantformant frequencies are odd multiples of F1
For examplebull F1 = (c4l )1
bull F2 = (c4l )3
bull F3 = (c4l )5
Comparing Helmholtz and tube resonators
Resonator Features
Sharply tuned Broadly tuned
Resonator Features
An example of the resonance characteristics of the human vocal tract
Frequency
Gain
SPPA 4030 Speech Science
Topic 1 The Speech Chain
The Speech Chain (Denes amp Pinson 1993)
What information is embedded in the speech signal
Branches of science employed to understand speech communication
Physical Quantities Review An Independent Learning Activity
Assignment 1
Topic 2 The Source-Filter Theory of Speech Production An Intr
Producing Speech
Source-Filter Theory of Speech Production
Vocal tract is a tube that can vary its shape
Source Filter Theory
Same Source Different Filter
Different Source Same Filters
Different Source Same Filters (Human)
Different Source Same Filters (Human) (2)
Different Source Same Filters (Human) (3)
Different Source Same Filters (Human) (4)
Different Source Same Filters (Non-Human)
Different Source Same Filters (Non-Human) (2)
Different Source Same Filters (Non-Human) If it quacks like a
Source Filter Theory Applied Alaryngeal Speech
Source-Filter Theory Applied Esophageal Insufflation Test
Source-Filter Theory Applied Tracheoesophageal (TE) Speech
Source Filter Theory Applied The Talkbox
Source-Filter Theory Applied The Talkbox
Topic 3 A Brief Review of Physical Acoustics
Spring Mass Model
What is sound
Sound-conducting media
Model of air molecule vibration (Time 1)
Model of air molecule vibration (Time 2)
Model of air molecule vibration (Time 3)
Model of air molecule vibration (Time 4)
Model of air molecule vibration (Time 5)
Model of air molecule vibration
Wave action of molecular motion
Amplitude waveform
Amplitude waveform (2)
Where is pressure in this model
Pressure waveform
Measuring Sound
Measuring Sound Signal Amplitude
Measuring Sound Signal Amplitude (2)
What units do we use to measure signal amplitude
Brief Review The decibel scale
Absolute vs relative measurement
Typical reference values
Howeverhellip
Linear vs logarithmic
Linear vs logarithmic (2)
Logarithmic Scale
Logarithmic Scale (2)
Combining the idea of logarithmic and relativehellip
Intensity vs Pressure
Extending the formula to pressure
Measuring Sound Frequencyperiod
Measuring Sound Frequencyperiod (2)
Phase Uniform Circular Motion
Initiating a sound waves that differ only in phase
Spatial variation in pressure wave
Spatial variation in pressure wave
Spatial variation in pressure wave (2)
Relation between frequency and wavelength
Learning Objectives
Graphic representation of sound
Same sound different graphs
Classification of sounds
Simple periodic sound
Simple periodic sound Graphic appearance
Complex periodic sounds
Complex periodic sounds Graphic appearance
Complex periodic sounds Graphic appearance (2)
Glottal Source
Amplitude vs Phase Spectrum
Amplitude vs Phase Spectrum (2)
(Complex) Aperiodic sounds
Aperiodic sounds Graphic appearance
Aperiodic sounds Graphic appearance (2)
Analysis of complex waves
Learning Objectives (2)
The ldquoenveloperdquo of a sound wave
Waveform envelope
Waveform envelope (2)
Spectrum envelope
Thought Question
Amplitude Spectrum Window Size
ldquoInstantaneousrdquo Amplitude Spectra
(Long Term) Average Amplitude Spectrum
Slide 90
Learning Objectives (3)
The Spectrogram
Building a spectrogram
Building a spectrogram
Building a spectrogram (2)
Two main types of spectrograms
Wide vs Narrow Band Spectrograms
Learning Objectives (4)
What is an ldquoAcousticrdquo Filter
Why might we be interested in filters
Kinds of frequency selective filters
Low Pass Filters
High Pass Filters
Band Pass Filter
Frequency Response Curve (FRC)
Operation of a filter on a signal
Learning Objectives (5)
Free vibration
Forced vibration
Forced vibration (2)
Resonance refers to
Back to the mass spring model
Acoustic Resonance
Acoustic Resonance (2)
Helmholtz Resonator
Actions of a Helmholtz Resonator
Other Acoustic Resonators Tube Resonators
Uniform tube closed at one end
Uniform tube closed at one end (2)
Uniform tube closed at one end
Comparing Helmholtz and tube resonators
Slide 122
Slide 123
Amplitude Spectrum Window Size
bull ldquoshort-termrdquo vs ldquolong-term averagerdquo amplitude spectrum
ldquoInstantaneousrdquo Amplitude Spectra
(Long Term) Average Amplitude Spectrum
Learning Objectivesbull Describe how the amplitude spectrum and the spectrogram are
relatedbull Identify the axis units of the spectrogrambull Provide some advantages of the spectrogram over the
amplitude spectrumbull Distinguish between a wide band and narrow band spectrogram
and outline the different information each providesbull Distinguish between a harmonic and a formant on a
spectrogrambull Be able to draw stylized (highly simplified) spectrograms based
on spectra and spectrum envelopes
The Spectrogram
Rotate90 degrees
F
AF
A
Building a spectrogram
Rotate it so thatThe amplitude isComing out of thepage
F
A This is really narrow because it is a slice in time
F
Time
Building a spectrogram
Dark bands= amplitudePeaks
Time
Freq
uenc
y
Building a spectrogram
Two main types of spectrograms
bull Narrow-band spectrogramsndash Akin to amplitude spectrums ldquolined uprdquondash Frequency resolution is really sharp
bull Wide-band spectrogramsndash Akin to spectrum envelopes ldquolined uprdquondash Frequency resolution not so sharp
Highlights harmonic structure
Highlights spectrum envelope
Wide vs Narrow Band Spectrograms
Learning Objectives
bull Define an acoustic filterbull Draw and label a frequency response curvebull Draw and differentiate different types of acoustic
filtersbull Define terms such as cutoff frequency center
frequency roll off rate gain and bandwidthbull Define and draw a basic filter system and relate that
to the source-filter theory of speech production
What is an ldquoAcousticrdquo Filter
bull holds back (attenuates) certain sounds and lets other sounds through - selective
Why might we be interested in filters
bull Human vocal tract acts like a frequency selective acoustic filter
bull Human auditory system behaves as a frequency selective filter
bull helps us understand how speech is produced and perceived
Kinds of frequency selective filters
Low-pass filtersndash Lets low frequencies ldquopass throughrdquo and attenuates high
frequencies
High-pass filtersndash Lets high frequencies ldquopass throughrdquo and attenuates low
frequencies
Band-pass filtersndash Lets a particular frequency range ldquopass throughrdquo and
attenuates other frequencies
Low Pass Filters
Frequencylow high
Gai
n
+
-
High Pass Filters
Frequencylow high
Gai
n
+
-
Band Pass Filter
Frequencylow high
Gai
n
+
-
Frequency Response Curve (FRC)
Frequencylow high
Gai
n
+
-
Center frequency
lower cutofffrequency
upper cutoff frequency
passband
3 dB
Operation of a filter on a signal
NOTE Amplitude spectrum describes a soundFrequency response curve describes a filter
Learning Objectivesbull Define resonance free and forced vibrationbull Describe how the pendulum and spring mass models can
help explain resonancebull Outline how mass and stiffness influences the resonant
frequency of a mass spring systembull Outline how acoustic resonators behave like acoustic filtersbull Calculate resonant frequencies of a uniform tube based on
its physical dimensionsbull Describe how the wavelength of the sound determines the
resonant frequency of tube
Free vibration
bull objects tend to vibrate at a characteristic or resonant frequency (RF)
Forced vibration
bull A vibrating system can force a nearby system into vibration
bull The efficiency with which this is accomplished is related to the similarity in the resonant frequency (RF) of the two systems
Forced vibration
bull If the RF of the two systems are the same the amplitude of forced vibration will be large
bull If the RF of the two systems are quite different the amplitude of forced vibration will be small or nonexistent
Resonance refers to
bull The tendency for an object to vibrate at a particular frequency or frequencies
bull The ability of a vibrating system to force another system into vibration
Back to the mass spring model
bull Vibratory frequency of the mass spring determined byndash Massndash Stiffness of the spring
httpphetcoloradoeduensimulationmass-spring-lab
Acoustic Resonance
bull Ideas from mechanical resonance also applies to acoustic systems
bull Acoustic chambers will transmit sound frequencies with more or less efficiency depending upon the physical characteristics
bull Therefore they act as filters passing through (and even amplifying) some frequencies and attentuating others
Acoustic Resonance
bull And since they act as filters they have most of the same features of a filter even though we might use different names
bull Center frequency is often termed the resonant frequency
bull Frequency response curve often termed the resonance curve
Helmholtz Resonator
Actions of a Helmholtz Resonator
Stephen M Tasko
Other Acoustic Resonators Tube Resonators
bull Uniform tubes Factors that influence resonancendash Lengthndash Cross-sectional area along its lengthndash Whether it is closed at either or both ends
Uniform tube closed at one end
Uniform tube closed at one end
Stephen M Tasko
Uniform tube closed at one end
First resonance or formant
F1 = c4lWhere
c=speed of sound (35000 cmsec)l = length of the tube
males ~ 175 cmfemales ~ 14 cm
Higher resonantformant frequencies are odd multiples of F1
For examplebull F1 = (c4l )1
bull F2 = (c4l )3
bull F3 = (c4l )5
Comparing Helmholtz and tube resonators
Resonator Features
Sharply tuned Broadly tuned
Resonator Features
An example of the resonance characteristics of the human vocal tract
Frequency
Gain
SPPA 4030 Speech Science
Topic 1 The Speech Chain
The Speech Chain (Denes amp Pinson 1993)
What information is embedded in the speech signal
Branches of science employed to understand speech communication
Physical Quantities Review An Independent Learning Activity
Assignment 1
Topic 2 The Source-Filter Theory of Speech Production An Intr
Producing Speech
Source-Filter Theory of Speech Production
Vocal tract is a tube that can vary its shape
Source Filter Theory
Same Source Different Filter
Different Source Same Filters
Different Source Same Filters (Human)
Different Source Same Filters (Human) (2)
Different Source Same Filters (Human) (3)
Different Source Same Filters (Human) (4)
Different Source Same Filters (Non-Human)
Different Source Same Filters (Non-Human) (2)
Different Source Same Filters (Non-Human) If it quacks like a
Source Filter Theory Applied Alaryngeal Speech
Source-Filter Theory Applied Esophageal Insufflation Test
Source-Filter Theory Applied Tracheoesophageal (TE) Speech
Source Filter Theory Applied The Talkbox
Source-Filter Theory Applied The Talkbox
Topic 3 A Brief Review of Physical Acoustics
Spring Mass Model
What is sound
Sound-conducting media
Model of air molecule vibration (Time 1)
Model of air molecule vibration (Time 2)
Model of air molecule vibration (Time 3)
Model of air molecule vibration (Time 4)
Model of air molecule vibration (Time 5)
Model of air molecule vibration
Wave action of molecular motion
Amplitude waveform
Amplitude waveform (2)
Where is pressure in this model
Pressure waveform
Measuring Sound
Measuring Sound Signal Amplitude
Measuring Sound Signal Amplitude (2)
What units do we use to measure signal amplitude
Brief Review The decibel scale
Absolute vs relative measurement
Typical reference values
Howeverhellip
Linear vs logarithmic
Linear vs logarithmic (2)
Logarithmic Scale
Logarithmic Scale (2)
Combining the idea of logarithmic and relativehellip
Intensity vs Pressure
Extending the formula to pressure
Measuring Sound Frequencyperiod
Measuring Sound Frequencyperiod (2)
Phase Uniform Circular Motion
Initiating a sound waves that differ only in phase
Spatial variation in pressure wave
Spatial variation in pressure wave
Spatial variation in pressure wave (2)
Relation between frequency and wavelength
Learning Objectives
Graphic representation of sound
Same sound different graphs
Classification of sounds
Simple periodic sound
Simple periodic sound Graphic appearance
Complex periodic sounds
Complex periodic sounds Graphic appearance
Complex periodic sounds Graphic appearance (2)
Glottal Source
Amplitude vs Phase Spectrum
Amplitude vs Phase Spectrum (2)
(Complex) Aperiodic sounds
Aperiodic sounds Graphic appearance
Aperiodic sounds Graphic appearance (2)
Analysis of complex waves
Learning Objectives (2)
The ldquoenveloperdquo of a sound wave
Waveform envelope
Waveform envelope (2)
Spectrum envelope
Thought Question
Amplitude Spectrum Window Size
ldquoInstantaneousrdquo Amplitude Spectra
(Long Term) Average Amplitude Spectrum
Slide 90
Learning Objectives (3)
The Spectrogram
Building a spectrogram
Building a spectrogram
Building a spectrogram (2)
Two main types of spectrograms
Wide vs Narrow Band Spectrograms
Learning Objectives (4)
What is an ldquoAcousticrdquo Filter
Why might we be interested in filters
Kinds of frequency selective filters
Low Pass Filters
High Pass Filters
Band Pass Filter
Frequency Response Curve (FRC)
Operation of a filter on a signal
Learning Objectives (5)
Free vibration
Forced vibration
Forced vibration (2)
Resonance refers to
Back to the mass spring model
Acoustic Resonance
Acoustic Resonance (2)
Helmholtz Resonator
Actions of a Helmholtz Resonator
Other Acoustic Resonators Tube Resonators
Uniform tube closed at one end
Uniform tube closed at one end (2)
Uniform tube closed at one end
Comparing Helmholtz and tube resonators
Slide 122
Slide 123
ldquoInstantaneousrdquo Amplitude Spectra
(Long Term) Average Amplitude Spectrum
Learning Objectivesbull Describe how the amplitude spectrum and the spectrogram are
relatedbull Identify the axis units of the spectrogrambull Provide some advantages of the spectrogram over the
amplitude spectrumbull Distinguish between a wide band and narrow band spectrogram
and outline the different information each providesbull Distinguish between a harmonic and a formant on a
spectrogrambull Be able to draw stylized (highly simplified) spectrograms based
on spectra and spectrum envelopes
The Spectrogram
Rotate90 degrees
F
AF
A
Building a spectrogram
Rotate it so thatThe amplitude isComing out of thepage
F
A This is really narrow because it is a slice in time
F
Time
Building a spectrogram
Dark bands= amplitudePeaks
Time
Freq
uenc
y
Building a spectrogram
Two main types of spectrograms
bull Narrow-band spectrogramsndash Akin to amplitude spectrums ldquolined uprdquondash Frequency resolution is really sharp
bull Wide-band spectrogramsndash Akin to spectrum envelopes ldquolined uprdquondash Frequency resolution not so sharp
Highlights harmonic structure
Highlights spectrum envelope
Wide vs Narrow Band Spectrograms
Learning Objectives
bull Define an acoustic filterbull Draw and label a frequency response curvebull Draw and differentiate different types of acoustic
filtersbull Define terms such as cutoff frequency center
frequency roll off rate gain and bandwidthbull Define and draw a basic filter system and relate that
to the source-filter theory of speech production
What is an ldquoAcousticrdquo Filter
bull holds back (attenuates) certain sounds and lets other sounds through - selective
Why might we be interested in filters
bull Human vocal tract acts like a frequency selective acoustic filter
bull Human auditory system behaves as a frequency selective filter
bull helps us understand how speech is produced and perceived
Kinds of frequency selective filters
Low-pass filtersndash Lets low frequencies ldquopass throughrdquo and attenuates high
frequencies
High-pass filtersndash Lets high frequencies ldquopass throughrdquo and attenuates low
frequencies
Band-pass filtersndash Lets a particular frequency range ldquopass throughrdquo and
attenuates other frequencies
Low Pass Filters
Frequencylow high
Gai
n
+
-
High Pass Filters
Frequencylow high
Gai
n
+
-
Band Pass Filter
Frequencylow high
Gai
n
+
-
Frequency Response Curve (FRC)
Frequencylow high
Gai
n
+
-
Center frequency
lower cutofffrequency
upper cutoff frequency
passband
3 dB
Operation of a filter on a signal
NOTE Amplitude spectrum describes a soundFrequency response curve describes a filter
Learning Objectivesbull Define resonance free and forced vibrationbull Describe how the pendulum and spring mass models can
help explain resonancebull Outline how mass and stiffness influences the resonant
frequency of a mass spring systembull Outline how acoustic resonators behave like acoustic filtersbull Calculate resonant frequencies of a uniform tube based on
its physical dimensionsbull Describe how the wavelength of the sound determines the
resonant frequency of tube
Free vibration
bull objects tend to vibrate at a characteristic or resonant frequency (RF)
Forced vibration
bull A vibrating system can force a nearby system into vibration
bull The efficiency with which this is accomplished is related to the similarity in the resonant frequency (RF) of the two systems
Forced vibration
bull If the RF of the two systems are the same the amplitude of forced vibration will be large
bull If the RF of the two systems are quite different the amplitude of forced vibration will be small or nonexistent
Resonance refers to
bull The tendency for an object to vibrate at a particular frequency or frequencies
bull The ability of a vibrating system to force another system into vibration
Back to the mass spring model
bull Vibratory frequency of the mass spring determined byndash Massndash Stiffness of the spring
httpphetcoloradoeduensimulationmass-spring-lab
Acoustic Resonance
bull Ideas from mechanical resonance also applies to acoustic systems
bull Acoustic chambers will transmit sound frequencies with more or less efficiency depending upon the physical characteristics
bull Therefore they act as filters passing through (and even amplifying) some frequencies and attentuating others
Acoustic Resonance
bull And since they act as filters they have most of the same features of a filter even though we might use different names
bull Center frequency is often termed the resonant frequency
bull Frequency response curve often termed the resonance curve
Helmholtz Resonator
Actions of a Helmholtz Resonator
Stephen M Tasko
Other Acoustic Resonators Tube Resonators
bull Uniform tubes Factors that influence resonancendash Lengthndash Cross-sectional area along its lengthndash Whether it is closed at either or both ends
Uniform tube closed at one end
Uniform tube closed at one end
Stephen M Tasko
Uniform tube closed at one end
First resonance or formant
F1 = c4lWhere
c=speed of sound (35000 cmsec)l = length of the tube
males ~ 175 cmfemales ~ 14 cm
Higher resonantformant frequencies are odd multiples of F1
For examplebull F1 = (c4l )1
bull F2 = (c4l )3
bull F3 = (c4l )5
Comparing Helmholtz and tube resonators
Resonator Features
Sharply tuned Broadly tuned
Resonator Features
An example of the resonance characteristics of the human vocal tract
Frequency
Gain
SPPA 4030 Speech Science
Topic 1 The Speech Chain
The Speech Chain (Denes amp Pinson 1993)
What information is embedded in the speech signal
Branches of science employed to understand speech communication
Physical Quantities Review An Independent Learning Activity
Assignment 1
Topic 2 The Source-Filter Theory of Speech Production An Intr
Producing Speech
Source-Filter Theory of Speech Production
Vocal tract is a tube that can vary its shape
Source Filter Theory
Same Source Different Filter
Different Source Same Filters
Different Source Same Filters (Human)
Different Source Same Filters (Human) (2)
Different Source Same Filters (Human) (3)
Different Source Same Filters (Human) (4)
Different Source Same Filters (Non-Human)
Different Source Same Filters (Non-Human) (2)
Different Source Same Filters (Non-Human) If it quacks like a
Source Filter Theory Applied Alaryngeal Speech
Source-Filter Theory Applied Esophageal Insufflation Test
Source-Filter Theory Applied Tracheoesophageal (TE) Speech
Source Filter Theory Applied The Talkbox
Source-Filter Theory Applied The Talkbox
Topic 3 A Brief Review of Physical Acoustics
Spring Mass Model
What is sound
Sound-conducting media
Model of air molecule vibration (Time 1)
Model of air molecule vibration (Time 2)
Model of air molecule vibration (Time 3)
Model of air molecule vibration (Time 4)
Model of air molecule vibration (Time 5)
Model of air molecule vibration
Wave action of molecular motion
Amplitude waveform
Amplitude waveform (2)
Where is pressure in this model
Pressure waveform
Measuring Sound
Measuring Sound Signal Amplitude
Measuring Sound Signal Amplitude (2)
What units do we use to measure signal amplitude
Brief Review The decibel scale
Absolute vs relative measurement
Typical reference values
Howeverhellip
Linear vs logarithmic
Linear vs logarithmic (2)
Logarithmic Scale
Logarithmic Scale (2)
Combining the idea of logarithmic and relativehellip
Intensity vs Pressure
Extending the formula to pressure
Measuring Sound Frequencyperiod
Measuring Sound Frequencyperiod (2)
Phase Uniform Circular Motion
Initiating a sound waves that differ only in phase
Spatial variation in pressure wave
Spatial variation in pressure wave
Spatial variation in pressure wave (2)
Relation between frequency and wavelength
Learning Objectives
Graphic representation of sound
Same sound different graphs
Classification of sounds
Simple periodic sound
Simple periodic sound Graphic appearance
Complex periodic sounds
Complex periodic sounds Graphic appearance
Complex periodic sounds Graphic appearance (2)
Glottal Source
Amplitude vs Phase Spectrum
Amplitude vs Phase Spectrum (2)
(Complex) Aperiodic sounds
Aperiodic sounds Graphic appearance
Aperiodic sounds Graphic appearance (2)
Analysis of complex waves
Learning Objectives (2)
The ldquoenveloperdquo of a sound wave
Waveform envelope
Waveform envelope (2)
Spectrum envelope
Thought Question
Amplitude Spectrum Window Size
ldquoInstantaneousrdquo Amplitude Spectra
(Long Term) Average Amplitude Spectrum
Slide 90
Learning Objectives (3)
The Spectrogram
Building a spectrogram
Building a spectrogram
Building a spectrogram (2)
Two main types of spectrograms
Wide vs Narrow Band Spectrograms
Learning Objectives (4)
What is an ldquoAcousticrdquo Filter
Why might we be interested in filters
Kinds of frequency selective filters
Low Pass Filters
High Pass Filters
Band Pass Filter
Frequency Response Curve (FRC)
Operation of a filter on a signal
Learning Objectives (5)
Free vibration
Forced vibration
Forced vibration (2)
Resonance refers to
Back to the mass spring model
Acoustic Resonance
Acoustic Resonance (2)
Helmholtz Resonator
Actions of a Helmholtz Resonator
Other Acoustic Resonators Tube Resonators
Uniform tube closed at one end
Uniform tube closed at one end (2)
Uniform tube closed at one end
Comparing Helmholtz and tube resonators
Slide 122
Slide 123
(Long Term) Average Amplitude Spectrum
Learning Objectivesbull Describe how the amplitude spectrum and the spectrogram are
relatedbull Identify the axis units of the spectrogrambull Provide some advantages of the spectrogram over the
amplitude spectrumbull Distinguish between a wide band and narrow band spectrogram
and outline the different information each providesbull Distinguish between a harmonic and a formant on a
spectrogrambull Be able to draw stylized (highly simplified) spectrograms based
on spectra and spectrum envelopes
The Spectrogram
Rotate90 degrees
F
AF
A
Building a spectrogram
Rotate it so thatThe amplitude isComing out of thepage
F
A This is really narrow because it is a slice in time
F
Time
Building a spectrogram
Dark bands= amplitudePeaks
Time
Freq
uenc
y
Building a spectrogram
Two main types of spectrograms
bull Narrow-band spectrogramsndash Akin to amplitude spectrums ldquolined uprdquondash Frequency resolution is really sharp
bull Wide-band spectrogramsndash Akin to spectrum envelopes ldquolined uprdquondash Frequency resolution not so sharp
Highlights harmonic structure
Highlights spectrum envelope
Wide vs Narrow Band Spectrograms
Learning Objectives
bull Define an acoustic filterbull Draw and label a frequency response curvebull Draw and differentiate different types of acoustic
filtersbull Define terms such as cutoff frequency center
frequency roll off rate gain and bandwidthbull Define and draw a basic filter system and relate that
to the source-filter theory of speech production
What is an ldquoAcousticrdquo Filter
bull holds back (attenuates) certain sounds and lets other sounds through - selective
Why might we be interested in filters
bull Human vocal tract acts like a frequency selective acoustic filter
bull Human auditory system behaves as a frequency selective filter
bull helps us understand how speech is produced and perceived
Kinds of frequency selective filters
Low-pass filtersndash Lets low frequencies ldquopass throughrdquo and attenuates high
frequencies
High-pass filtersndash Lets high frequencies ldquopass throughrdquo and attenuates low
frequencies
Band-pass filtersndash Lets a particular frequency range ldquopass throughrdquo and
attenuates other frequencies
Low Pass Filters
Frequencylow high
Gai
n
+
-
High Pass Filters
Frequencylow high
Gai
n
+
-
Band Pass Filter
Frequencylow high
Gai
n
+
-
Frequency Response Curve (FRC)
Frequencylow high
Gai
n
+
-
Center frequency
lower cutofffrequency
upper cutoff frequency
passband
3 dB
Operation of a filter on a signal
NOTE Amplitude spectrum describes a soundFrequency response curve describes a filter
Learning Objectivesbull Define resonance free and forced vibrationbull Describe how the pendulum and spring mass models can
help explain resonancebull Outline how mass and stiffness influences the resonant
frequency of a mass spring systembull Outline how acoustic resonators behave like acoustic filtersbull Calculate resonant frequencies of a uniform tube based on
its physical dimensionsbull Describe how the wavelength of the sound determines the
resonant frequency of tube
Free vibration
bull objects tend to vibrate at a characteristic or resonant frequency (RF)
Forced vibration
bull A vibrating system can force a nearby system into vibration
bull The efficiency with which this is accomplished is related to the similarity in the resonant frequency (RF) of the two systems
Forced vibration
bull If the RF of the two systems are the same the amplitude of forced vibration will be large
bull If the RF of the two systems are quite different the amplitude of forced vibration will be small or nonexistent
Resonance refers to
bull The tendency for an object to vibrate at a particular frequency or frequencies
bull The ability of a vibrating system to force another system into vibration
Back to the mass spring model
bull Vibratory frequency of the mass spring determined byndash Massndash Stiffness of the spring
httpphetcoloradoeduensimulationmass-spring-lab
Acoustic Resonance
bull Ideas from mechanical resonance also applies to acoustic systems
bull Acoustic chambers will transmit sound frequencies with more or less efficiency depending upon the physical characteristics
bull Therefore they act as filters passing through (and even amplifying) some frequencies and attentuating others
Acoustic Resonance
bull And since they act as filters they have most of the same features of a filter even though we might use different names
bull Center frequency is often termed the resonant frequency
bull Frequency response curve often termed the resonance curve
Helmholtz Resonator
Actions of a Helmholtz Resonator
Stephen M Tasko
Other Acoustic Resonators Tube Resonators
bull Uniform tubes Factors that influence resonancendash Lengthndash Cross-sectional area along its lengthndash Whether it is closed at either or both ends
Uniform tube closed at one end
Uniform tube closed at one end
Stephen M Tasko
Uniform tube closed at one end
First resonance or formant
F1 = c4lWhere
c=speed of sound (35000 cmsec)l = length of the tube
males ~ 175 cmfemales ~ 14 cm
Higher resonantformant frequencies are odd multiples of F1
For examplebull F1 = (c4l )1
bull F2 = (c4l )3
bull F3 = (c4l )5
Comparing Helmholtz and tube resonators
Resonator Features
Sharply tuned Broadly tuned
Resonator Features
An example of the resonance characteristics of the human vocal tract
Frequency
Gain
SPPA 4030 Speech Science
Topic 1 The Speech Chain
The Speech Chain (Denes amp Pinson 1993)
What information is embedded in the speech signal
Branches of science employed to understand speech communication
Physical Quantities Review An Independent Learning Activity
Assignment 1
Topic 2 The Source-Filter Theory of Speech Production An Intr
Producing Speech
Source-Filter Theory of Speech Production
Vocal tract is a tube that can vary its shape
Source Filter Theory
Same Source Different Filter
Different Source Same Filters
Different Source Same Filters (Human)
Different Source Same Filters (Human) (2)
Different Source Same Filters (Human) (3)
Different Source Same Filters (Human) (4)
Different Source Same Filters (Non-Human)
Different Source Same Filters (Non-Human) (2)
Different Source Same Filters (Non-Human) If it quacks like a
Source Filter Theory Applied Alaryngeal Speech
Source-Filter Theory Applied Esophageal Insufflation Test
Source-Filter Theory Applied Tracheoesophageal (TE) Speech
Source Filter Theory Applied The Talkbox
Source-Filter Theory Applied The Talkbox
Topic 3 A Brief Review of Physical Acoustics
Spring Mass Model
What is sound
Sound-conducting media
Model of air molecule vibration (Time 1)
Model of air molecule vibration (Time 2)
Model of air molecule vibration (Time 3)
Model of air molecule vibration (Time 4)
Model of air molecule vibration (Time 5)
Model of air molecule vibration
Wave action of molecular motion
Amplitude waveform
Amplitude waveform (2)
Where is pressure in this model
Pressure waveform
Measuring Sound
Measuring Sound Signal Amplitude
Measuring Sound Signal Amplitude (2)
What units do we use to measure signal amplitude
Brief Review The decibel scale
Absolute vs relative measurement
Typical reference values
Howeverhellip
Linear vs logarithmic
Linear vs logarithmic (2)
Logarithmic Scale
Logarithmic Scale (2)
Combining the idea of logarithmic and relativehellip
Intensity vs Pressure
Extending the formula to pressure
Measuring Sound Frequencyperiod
Measuring Sound Frequencyperiod (2)
Phase Uniform Circular Motion
Initiating a sound waves that differ only in phase
Spatial variation in pressure wave
Spatial variation in pressure wave
Spatial variation in pressure wave (2)
Relation between frequency and wavelength
Learning Objectives
Graphic representation of sound
Same sound different graphs
Classification of sounds
Simple periodic sound
Simple periodic sound Graphic appearance
Complex periodic sounds
Complex periodic sounds Graphic appearance
Complex periodic sounds Graphic appearance (2)
Glottal Source
Amplitude vs Phase Spectrum
Amplitude vs Phase Spectrum (2)
(Complex) Aperiodic sounds
Aperiodic sounds Graphic appearance
Aperiodic sounds Graphic appearance (2)
Analysis of complex waves
Learning Objectives (2)
The ldquoenveloperdquo of a sound wave
Waveform envelope
Waveform envelope (2)
Spectrum envelope
Thought Question
Amplitude Spectrum Window Size
ldquoInstantaneousrdquo Amplitude Spectra
(Long Term) Average Amplitude Spectrum
Slide 90
Learning Objectives (3)
The Spectrogram
Building a spectrogram
Building a spectrogram
Building a spectrogram (2)
Two main types of spectrograms
Wide vs Narrow Band Spectrograms
Learning Objectives (4)
What is an ldquoAcousticrdquo Filter
Why might we be interested in filters
Kinds of frequency selective filters
Low Pass Filters
High Pass Filters
Band Pass Filter
Frequency Response Curve (FRC)
Operation of a filter on a signal
Learning Objectives (5)
Free vibration
Forced vibration
Forced vibration (2)
Resonance refers to
Back to the mass spring model
Acoustic Resonance
Acoustic Resonance (2)
Helmholtz Resonator
Actions of a Helmholtz Resonator
Other Acoustic Resonators Tube Resonators
Uniform tube closed at one end
Uniform tube closed at one end (2)
Uniform tube closed at one end
Comparing Helmholtz and tube resonators
Slide 122
Slide 123
Learning Objectivesbull Describe how the amplitude spectrum and the spectrogram are
relatedbull Identify the axis units of the spectrogrambull Provide some advantages of the spectrogram over the
amplitude spectrumbull Distinguish between a wide band and narrow band spectrogram
and outline the different information each providesbull Distinguish between a harmonic and a formant on a
spectrogrambull Be able to draw stylized (highly simplified) spectrograms based
on spectra and spectrum envelopes
The Spectrogram
Rotate90 degrees
F
AF
A
Building a spectrogram
Rotate it so thatThe amplitude isComing out of thepage
F
A This is really narrow because it is a slice in time
F
Time
Building a spectrogram
Dark bands= amplitudePeaks
Time
Freq
uenc
y
Building a spectrogram
Two main types of spectrograms
bull Narrow-band spectrogramsndash Akin to amplitude spectrums ldquolined uprdquondash Frequency resolution is really sharp
bull Wide-band spectrogramsndash Akin to spectrum envelopes ldquolined uprdquondash Frequency resolution not so sharp
Highlights harmonic structure
Highlights spectrum envelope
Wide vs Narrow Band Spectrograms
Learning Objectives
bull Define an acoustic filterbull Draw and label a frequency response curvebull Draw and differentiate different types of acoustic
filtersbull Define terms such as cutoff frequency center
frequency roll off rate gain and bandwidthbull Define and draw a basic filter system and relate that
to the source-filter theory of speech production
What is an ldquoAcousticrdquo Filter
bull holds back (attenuates) certain sounds and lets other sounds through - selective
Why might we be interested in filters
bull Human vocal tract acts like a frequency selective acoustic filter
bull Human auditory system behaves as a frequency selective filter
bull helps us understand how speech is produced and perceived
Kinds of frequency selective filters
Low-pass filtersndash Lets low frequencies ldquopass throughrdquo and attenuates high
frequencies
High-pass filtersndash Lets high frequencies ldquopass throughrdquo and attenuates low
frequencies
Band-pass filtersndash Lets a particular frequency range ldquopass throughrdquo and
attenuates other frequencies
Low Pass Filters
Frequencylow high
Gai
n
+
-
High Pass Filters
Frequencylow high
Gai
n
+
-
Band Pass Filter
Frequencylow high
Gai
n
+
-
Frequency Response Curve (FRC)
Frequencylow high
Gai
n
+
-
Center frequency
lower cutofffrequency
upper cutoff frequency
passband
3 dB
Operation of a filter on a signal
NOTE Amplitude spectrum describes a soundFrequency response curve describes a filter
Learning Objectivesbull Define resonance free and forced vibrationbull Describe how the pendulum and spring mass models can
help explain resonancebull Outline how mass and stiffness influences the resonant
frequency of a mass spring systembull Outline how acoustic resonators behave like acoustic filtersbull Calculate resonant frequencies of a uniform tube based on
its physical dimensionsbull Describe how the wavelength of the sound determines the
resonant frequency of tube
Free vibration
bull objects tend to vibrate at a characteristic or resonant frequency (RF)
Forced vibration
bull A vibrating system can force a nearby system into vibration
bull The efficiency with which this is accomplished is related to the similarity in the resonant frequency (RF) of the two systems
Forced vibration
bull If the RF of the two systems are the same the amplitude of forced vibration will be large
bull If the RF of the two systems are quite different the amplitude of forced vibration will be small or nonexistent
Resonance refers to
bull The tendency for an object to vibrate at a particular frequency or frequencies
bull The ability of a vibrating system to force another system into vibration
Back to the mass spring model
bull Vibratory frequency of the mass spring determined byndash Massndash Stiffness of the spring
httpphetcoloradoeduensimulationmass-spring-lab
Acoustic Resonance
bull Ideas from mechanical resonance also applies to acoustic systems
bull Acoustic chambers will transmit sound frequencies with more or less efficiency depending upon the physical characteristics
bull Therefore they act as filters passing through (and even amplifying) some frequencies and attentuating others
Acoustic Resonance
bull And since they act as filters they have most of the same features of a filter even though we might use different names
bull Center frequency is often termed the resonant frequency
bull Frequency response curve often termed the resonance curve
Helmholtz Resonator
Actions of a Helmholtz Resonator
Stephen M Tasko
Other Acoustic Resonators Tube Resonators
bull Uniform tubes Factors that influence resonancendash Lengthndash Cross-sectional area along its lengthndash Whether it is closed at either or both ends
Uniform tube closed at one end
Uniform tube closed at one end
Stephen M Tasko
Uniform tube closed at one end
First resonance or formant
F1 = c4lWhere
c=speed of sound (35000 cmsec)l = length of the tube
males ~ 175 cmfemales ~ 14 cm
Higher resonantformant frequencies are odd multiples of F1
For examplebull F1 = (c4l )1
bull F2 = (c4l )3
bull F3 = (c4l )5
Comparing Helmholtz and tube resonators
Resonator Features
Sharply tuned Broadly tuned
Resonator Features
An example of the resonance characteristics of the human vocal tract
Frequency
Gain
SPPA 4030 Speech Science
Topic 1 The Speech Chain
The Speech Chain (Denes amp Pinson 1993)
What information is embedded in the speech signal
Branches of science employed to understand speech communication
Physical Quantities Review An Independent Learning Activity
Assignment 1
Topic 2 The Source-Filter Theory of Speech Production An Intr
Producing Speech
Source-Filter Theory of Speech Production
Vocal tract is a tube that can vary its shape
Source Filter Theory
Same Source Different Filter
Different Source Same Filters
Different Source Same Filters (Human)
Different Source Same Filters (Human) (2)
Different Source Same Filters (Human) (3)
Different Source Same Filters (Human) (4)
Different Source Same Filters (Non-Human)
Different Source Same Filters (Non-Human) (2)
Different Source Same Filters (Non-Human) If it quacks like a
Source Filter Theory Applied Alaryngeal Speech
Source-Filter Theory Applied Esophageal Insufflation Test
Source-Filter Theory Applied Tracheoesophageal (TE) Speech
Source Filter Theory Applied The Talkbox
Source-Filter Theory Applied The Talkbox
Topic 3 A Brief Review of Physical Acoustics
Spring Mass Model
What is sound
Sound-conducting media
Model of air molecule vibration (Time 1)
Model of air molecule vibration (Time 2)
Model of air molecule vibration (Time 3)
Model of air molecule vibration (Time 4)
Model of air molecule vibration (Time 5)
Model of air molecule vibration
Wave action of molecular motion
Amplitude waveform
Amplitude waveform (2)
Where is pressure in this model
Pressure waveform
Measuring Sound
Measuring Sound Signal Amplitude
Measuring Sound Signal Amplitude (2)
What units do we use to measure signal amplitude
Brief Review The decibel scale
Absolute vs relative measurement
Typical reference values
Howeverhellip
Linear vs logarithmic
Linear vs logarithmic (2)
Logarithmic Scale
Logarithmic Scale (2)
Combining the idea of logarithmic and relativehellip
Intensity vs Pressure
Extending the formula to pressure
Measuring Sound Frequencyperiod
Measuring Sound Frequencyperiod (2)
Phase Uniform Circular Motion
Initiating a sound waves that differ only in phase
Spatial variation in pressure wave
Spatial variation in pressure wave
Spatial variation in pressure wave (2)
Relation between frequency and wavelength
Learning Objectives
Graphic representation of sound
Same sound different graphs
Classification of sounds
Simple periodic sound
Simple periodic sound Graphic appearance
Complex periodic sounds
Complex periodic sounds Graphic appearance
Complex periodic sounds Graphic appearance (2)
Glottal Source
Amplitude vs Phase Spectrum
Amplitude vs Phase Spectrum (2)
(Complex) Aperiodic sounds
Aperiodic sounds Graphic appearance
Aperiodic sounds Graphic appearance (2)
Analysis of complex waves
Learning Objectives (2)
The ldquoenveloperdquo of a sound wave
Waveform envelope
Waveform envelope (2)
Spectrum envelope
Thought Question
Amplitude Spectrum Window Size
ldquoInstantaneousrdquo Amplitude Spectra
(Long Term) Average Amplitude Spectrum
Slide 90
Learning Objectives (3)
The Spectrogram
Building a spectrogram
Building a spectrogram
Building a spectrogram (2)
Two main types of spectrograms
Wide vs Narrow Band Spectrograms
Learning Objectives (4)
What is an ldquoAcousticrdquo Filter
Why might we be interested in filters
Kinds of frequency selective filters
Low Pass Filters
High Pass Filters
Band Pass Filter
Frequency Response Curve (FRC)
Operation of a filter on a signal
Learning Objectives (5)
Free vibration
Forced vibration
Forced vibration (2)
Resonance refers to
Back to the mass spring model
Acoustic Resonance
Acoustic Resonance (2)
Helmholtz Resonator
Actions of a Helmholtz Resonator
Other Acoustic Resonators Tube Resonators
Uniform tube closed at one end
Uniform tube closed at one end (2)
Uniform tube closed at one end
Comparing Helmholtz and tube resonators
Slide 122
Slide 123
The Spectrogram
Rotate90 degrees
F
AF
A
Building a spectrogram
Rotate it so thatThe amplitude isComing out of thepage
F
A This is really narrow because it is a slice in time
F
Time
Building a spectrogram
Dark bands= amplitudePeaks
Time
Freq
uenc
y
Building a spectrogram
Two main types of spectrograms
bull Narrow-band spectrogramsndash Akin to amplitude spectrums ldquolined uprdquondash Frequency resolution is really sharp
bull Wide-band spectrogramsndash Akin to spectrum envelopes ldquolined uprdquondash Frequency resolution not so sharp
Highlights harmonic structure
Highlights spectrum envelope
Wide vs Narrow Band Spectrograms
Learning Objectives
bull Define an acoustic filterbull Draw and label a frequency response curvebull Draw and differentiate different types of acoustic
filtersbull Define terms such as cutoff frequency center
frequency roll off rate gain and bandwidthbull Define and draw a basic filter system and relate that
to the source-filter theory of speech production
What is an ldquoAcousticrdquo Filter
bull holds back (attenuates) certain sounds and lets other sounds through - selective
Why might we be interested in filters
bull Human vocal tract acts like a frequency selective acoustic filter
bull Human auditory system behaves as a frequency selective filter
bull helps us understand how speech is produced and perceived
Kinds of frequency selective filters
Low-pass filtersndash Lets low frequencies ldquopass throughrdquo and attenuates high
frequencies
High-pass filtersndash Lets high frequencies ldquopass throughrdquo and attenuates low
frequencies
Band-pass filtersndash Lets a particular frequency range ldquopass throughrdquo and
attenuates other frequencies
Low Pass Filters
Frequencylow high
Gai
n
+
-
High Pass Filters
Frequencylow high
Gai
n
+
-
Band Pass Filter
Frequencylow high
Gai
n
+
-
Frequency Response Curve (FRC)
Frequencylow high
Gai
n
+
-
Center frequency
lower cutofffrequency
upper cutoff frequency
passband
3 dB
Operation of a filter on a signal
NOTE Amplitude spectrum describes a soundFrequency response curve describes a filter
Learning Objectivesbull Define resonance free and forced vibrationbull Describe how the pendulum and spring mass models can
help explain resonancebull Outline how mass and stiffness influences the resonant
frequency of a mass spring systembull Outline how acoustic resonators behave like acoustic filtersbull Calculate resonant frequencies of a uniform tube based on
its physical dimensionsbull Describe how the wavelength of the sound determines the
resonant frequency of tube
Free vibration
bull objects tend to vibrate at a characteristic or resonant frequency (RF)
Forced vibration
bull A vibrating system can force a nearby system into vibration
bull The efficiency with which this is accomplished is related to the similarity in the resonant frequency (RF) of the two systems
Forced vibration
bull If the RF of the two systems are the same the amplitude of forced vibration will be large
bull If the RF of the two systems are quite different the amplitude of forced vibration will be small or nonexistent
Resonance refers to
bull The tendency for an object to vibrate at a particular frequency or frequencies
bull The ability of a vibrating system to force another system into vibration
Back to the mass spring model
bull Vibratory frequency of the mass spring determined byndash Massndash Stiffness of the spring
httpphetcoloradoeduensimulationmass-spring-lab
Acoustic Resonance
bull Ideas from mechanical resonance also applies to acoustic systems
bull Acoustic chambers will transmit sound frequencies with more or less efficiency depending upon the physical characteristics
bull Therefore they act as filters passing through (and even amplifying) some frequencies and attentuating others
Acoustic Resonance
bull And since they act as filters they have most of the same features of a filter even though we might use different names
bull Center frequency is often termed the resonant frequency
bull Frequency response curve often termed the resonance curve
Helmholtz Resonator
Actions of a Helmholtz Resonator
Stephen M Tasko
Other Acoustic Resonators Tube Resonators
bull Uniform tubes Factors that influence resonancendash Lengthndash Cross-sectional area along its lengthndash Whether it is closed at either or both ends
Uniform tube closed at one end
Uniform tube closed at one end
Stephen M Tasko
Uniform tube closed at one end
First resonance or formant
F1 = c4lWhere
c=speed of sound (35000 cmsec)l = length of the tube
males ~ 175 cmfemales ~ 14 cm
Higher resonantformant frequencies are odd multiples of F1
For examplebull F1 = (c4l )1
bull F2 = (c4l )3
bull F3 = (c4l )5
Comparing Helmholtz and tube resonators
Resonator Features
Sharply tuned Broadly tuned
Resonator Features
An example of the resonance characteristics of the human vocal tract
Frequency
Gain
SPPA 4030 Speech Science
Topic 1 The Speech Chain
The Speech Chain (Denes amp Pinson 1993)
What information is embedded in the speech signal
Branches of science employed to understand speech communication
Physical Quantities Review An Independent Learning Activity
Assignment 1
Topic 2 The Source-Filter Theory of Speech Production An Intr
Producing Speech
Source-Filter Theory of Speech Production
Vocal tract is a tube that can vary its shape
Source Filter Theory
Same Source Different Filter
Different Source Same Filters
Different Source Same Filters (Human)
Different Source Same Filters (Human) (2)
Different Source Same Filters (Human) (3)
Different Source Same Filters (Human) (4)
Different Source Same Filters (Non-Human)
Different Source Same Filters (Non-Human) (2)
Different Source Same Filters (Non-Human) If it quacks like a
Source Filter Theory Applied Alaryngeal Speech
Source-Filter Theory Applied Esophageal Insufflation Test
Source-Filter Theory Applied Tracheoesophageal (TE) Speech
Source Filter Theory Applied The Talkbox
Source-Filter Theory Applied The Talkbox
Topic 3 A Brief Review of Physical Acoustics
Spring Mass Model
What is sound
Sound-conducting media
Model of air molecule vibration (Time 1)
Model of air molecule vibration (Time 2)
Model of air molecule vibration (Time 3)
Model of air molecule vibration (Time 4)
Model of air molecule vibration (Time 5)
Model of air molecule vibration
Wave action of molecular motion
Amplitude waveform
Amplitude waveform (2)
Where is pressure in this model
Pressure waveform
Measuring Sound
Measuring Sound Signal Amplitude
Measuring Sound Signal Amplitude (2)
What units do we use to measure signal amplitude
Brief Review The decibel scale
Absolute vs relative measurement
Typical reference values
Howeverhellip
Linear vs logarithmic
Linear vs logarithmic (2)
Logarithmic Scale
Logarithmic Scale (2)
Combining the idea of logarithmic and relativehellip
Intensity vs Pressure
Extending the formula to pressure
Measuring Sound Frequencyperiod
Measuring Sound Frequencyperiod (2)
Phase Uniform Circular Motion
Initiating a sound waves that differ only in phase
Spatial variation in pressure wave
Spatial variation in pressure wave
Spatial variation in pressure wave (2)
Relation between frequency and wavelength
Learning Objectives
Graphic representation of sound
Same sound different graphs
Classification of sounds
Simple periodic sound
Simple periodic sound Graphic appearance
Complex periodic sounds
Complex periodic sounds Graphic appearance
Complex periodic sounds Graphic appearance (2)
Glottal Source
Amplitude vs Phase Spectrum
Amplitude vs Phase Spectrum (2)
(Complex) Aperiodic sounds
Aperiodic sounds Graphic appearance
Aperiodic sounds Graphic appearance (2)
Analysis of complex waves
Learning Objectives (2)
The ldquoenveloperdquo of a sound wave
Waveform envelope
Waveform envelope (2)
Spectrum envelope
Thought Question
Amplitude Spectrum Window Size
ldquoInstantaneousrdquo Amplitude Spectra
(Long Term) Average Amplitude Spectrum
Slide 90
Learning Objectives (3)
The Spectrogram
Building a spectrogram
Building a spectrogram
Building a spectrogram (2)
Two main types of spectrograms
Wide vs Narrow Band Spectrograms
Learning Objectives (4)
What is an ldquoAcousticrdquo Filter
Why might we be interested in filters
Kinds of frequency selective filters
Low Pass Filters
High Pass Filters
Band Pass Filter
Frequency Response Curve (FRC)
Operation of a filter on a signal
Learning Objectives (5)
Free vibration
Forced vibration
Forced vibration (2)
Resonance refers to
Back to the mass spring model
Acoustic Resonance
Acoustic Resonance (2)
Helmholtz Resonator
Actions of a Helmholtz Resonator
Other Acoustic Resonators Tube Resonators
Uniform tube closed at one end
Uniform tube closed at one end (2)
Uniform tube closed at one end
Comparing Helmholtz and tube resonators
Slide 122
Slide 123
Rotate90 degrees
F
AF
A
Building a spectrogram
Rotate it so thatThe amplitude isComing out of thepage
F
A This is really narrow because it is a slice in time
F
Time
Building a spectrogram
Dark bands= amplitudePeaks
Time
Freq
uenc
y
Building a spectrogram
Two main types of spectrograms
bull Narrow-band spectrogramsndash Akin to amplitude spectrums ldquolined uprdquondash Frequency resolution is really sharp
bull Wide-band spectrogramsndash Akin to spectrum envelopes ldquolined uprdquondash Frequency resolution not so sharp
Highlights harmonic structure
Highlights spectrum envelope
Wide vs Narrow Band Spectrograms
Learning Objectives
bull Define an acoustic filterbull Draw and label a frequency response curvebull Draw and differentiate different types of acoustic
filtersbull Define terms such as cutoff frequency center
frequency roll off rate gain and bandwidthbull Define and draw a basic filter system and relate that
to the source-filter theory of speech production
What is an ldquoAcousticrdquo Filter
bull holds back (attenuates) certain sounds and lets other sounds through - selective
Why might we be interested in filters
bull Human vocal tract acts like a frequency selective acoustic filter
bull Human auditory system behaves as a frequency selective filter
bull helps us understand how speech is produced and perceived
Kinds of frequency selective filters
Low-pass filtersndash Lets low frequencies ldquopass throughrdquo and attenuates high
frequencies
High-pass filtersndash Lets high frequencies ldquopass throughrdquo and attenuates low
frequencies
Band-pass filtersndash Lets a particular frequency range ldquopass throughrdquo and
attenuates other frequencies
Low Pass Filters
Frequencylow high
Gai
n
+
-
High Pass Filters
Frequencylow high
Gai
n
+
-
Band Pass Filter
Frequencylow high
Gai
n
+
-
Frequency Response Curve (FRC)
Frequencylow high
Gai
n
+
-
Center frequency
lower cutofffrequency
upper cutoff frequency
passband
3 dB
Operation of a filter on a signal
NOTE Amplitude spectrum describes a soundFrequency response curve describes a filter
Learning Objectivesbull Define resonance free and forced vibrationbull Describe how the pendulum and spring mass models can
help explain resonancebull Outline how mass and stiffness influences the resonant
frequency of a mass spring systembull Outline how acoustic resonators behave like acoustic filtersbull Calculate resonant frequencies of a uniform tube based on
its physical dimensionsbull Describe how the wavelength of the sound determines the
resonant frequency of tube
Free vibration
bull objects tend to vibrate at a characteristic or resonant frequency (RF)
Forced vibration
bull A vibrating system can force a nearby system into vibration
bull The efficiency with which this is accomplished is related to the similarity in the resonant frequency (RF) of the two systems
Forced vibration
bull If the RF of the two systems are the same the amplitude of forced vibration will be large
bull If the RF of the two systems are quite different the amplitude of forced vibration will be small or nonexistent
Resonance refers to
bull The tendency for an object to vibrate at a particular frequency or frequencies
bull The ability of a vibrating system to force another system into vibration
Back to the mass spring model
bull Vibratory frequency of the mass spring determined byndash Massndash Stiffness of the spring
httpphetcoloradoeduensimulationmass-spring-lab
Acoustic Resonance
bull Ideas from mechanical resonance also applies to acoustic systems
bull Acoustic chambers will transmit sound frequencies with more or less efficiency depending upon the physical characteristics
bull Therefore they act as filters passing through (and even amplifying) some frequencies and attentuating others
Acoustic Resonance
bull And since they act as filters they have most of the same features of a filter even though we might use different names
bull Center frequency is often termed the resonant frequency
bull Frequency response curve often termed the resonance curve
Helmholtz Resonator
Actions of a Helmholtz Resonator
Stephen M Tasko
Other Acoustic Resonators Tube Resonators
bull Uniform tubes Factors that influence resonancendash Lengthndash Cross-sectional area along its lengthndash Whether it is closed at either or both ends
Uniform tube closed at one end
Uniform tube closed at one end
Stephen M Tasko
Uniform tube closed at one end
First resonance or formant
F1 = c4lWhere
c=speed of sound (35000 cmsec)l = length of the tube
males ~ 175 cmfemales ~ 14 cm
Higher resonantformant frequencies are odd multiples of F1
For examplebull F1 = (c4l )1
bull F2 = (c4l )3
bull F3 = (c4l )5
Comparing Helmholtz and tube resonators
Resonator Features
Sharply tuned Broadly tuned
Resonator Features
An example of the resonance characteristics of the human vocal tract
Frequency
Gain
SPPA 4030 Speech Science
Topic 1 The Speech Chain
The Speech Chain (Denes amp Pinson 1993)
What information is embedded in the speech signal
Branches of science employed to understand speech communication
Physical Quantities Review An Independent Learning Activity
Assignment 1
Topic 2 The Source-Filter Theory of Speech Production An Intr
Producing Speech
Source-Filter Theory of Speech Production
Vocal tract is a tube that can vary its shape
Source Filter Theory
Same Source Different Filter
Different Source Same Filters
Different Source Same Filters (Human)
Different Source Same Filters (Human) (2)
Different Source Same Filters (Human) (3)
Different Source Same Filters (Human) (4)
Different Source Same Filters (Non-Human)
Different Source Same Filters (Non-Human) (2)
Different Source Same Filters (Non-Human) If it quacks like a
Source Filter Theory Applied Alaryngeal Speech
Source-Filter Theory Applied Esophageal Insufflation Test
Source-Filter Theory Applied Tracheoesophageal (TE) Speech
Source Filter Theory Applied The Talkbox
Source-Filter Theory Applied The Talkbox
Topic 3 A Brief Review of Physical Acoustics
Spring Mass Model
What is sound
Sound-conducting media
Model of air molecule vibration (Time 1)
Model of air molecule vibration (Time 2)
Model of air molecule vibration (Time 3)
Model of air molecule vibration (Time 4)
Model of air molecule vibration (Time 5)
Model of air molecule vibration
Wave action of molecular motion
Amplitude waveform
Amplitude waveform (2)
Where is pressure in this model
Pressure waveform
Measuring Sound
Measuring Sound Signal Amplitude
Measuring Sound Signal Amplitude (2)
What units do we use to measure signal amplitude
Brief Review The decibel scale
Absolute vs relative measurement
Typical reference values
Howeverhellip
Linear vs logarithmic
Linear vs logarithmic (2)
Logarithmic Scale
Logarithmic Scale (2)
Combining the idea of logarithmic and relativehellip
Intensity vs Pressure
Extending the formula to pressure
Measuring Sound Frequencyperiod
Measuring Sound Frequencyperiod (2)
Phase Uniform Circular Motion
Initiating a sound waves that differ only in phase
Spatial variation in pressure wave
Spatial variation in pressure wave
Spatial variation in pressure wave (2)
Relation between frequency and wavelength
Learning Objectives
Graphic representation of sound
Same sound different graphs
Classification of sounds
Simple periodic sound
Simple periodic sound Graphic appearance
Complex periodic sounds
Complex periodic sounds Graphic appearance
Complex periodic sounds Graphic appearance (2)
Glottal Source
Amplitude vs Phase Spectrum
Amplitude vs Phase Spectrum (2)
(Complex) Aperiodic sounds
Aperiodic sounds Graphic appearance
Aperiodic sounds Graphic appearance (2)
Analysis of complex waves
Learning Objectives (2)
The ldquoenveloperdquo of a sound wave
Waveform envelope
Waveform envelope (2)
Spectrum envelope
Thought Question
Amplitude Spectrum Window Size
ldquoInstantaneousrdquo Amplitude Spectra
(Long Term) Average Amplitude Spectrum
Slide 90
Learning Objectives (3)
The Spectrogram
Building a spectrogram
Building a spectrogram
Building a spectrogram (2)
Two main types of spectrograms
Wide vs Narrow Band Spectrograms
Learning Objectives (4)
What is an ldquoAcousticrdquo Filter
Why might we be interested in filters
Kinds of frequency selective filters
Low Pass Filters
High Pass Filters
Band Pass Filter
Frequency Response Curve (FRC)
Operation of a filter on a signal
Learning Objectives (5)
Free vibration
Forced vibration
Forced vibration (2)
Resonance refers to
Back to the mass spring model
Acoustic Resonance
Acoustic Resonance (2)
Helmholtz Resonator
Actions of a Helmholtz Resonator
Other Acoustic Resonators Tube Resonators
Uniform tube closed at one end
Uniform tube closed at one end (2)
Uniform tube closed at one end
Comparing Helmholtz and tube resonators
Slide 122
Slide 123
Rotate it so thatThe amplitude isComing out of thepage
F
A This is really narrow because it is a slice in time
F
Time
Building a spectrogram
Dark bands= amplitudePeaks
Time
Freq
uenc
y
Building a spectrogram
Two main types of spectrograms
bull Narrow-band spectrogramsndash Akin to amplitude spectrums ldquolined uprdquondash Frequency resolution is really sharp
bull Wide-band spectrogramsndash Akin to spectrum envelopes ldquolined uprdquondash Frequency resolution not so sharp
Highlights harmonic structure
Highlights spectrum envelope
Wide vs Narrow Band Spectrograms
Learning Objectives
bull Define an acoustic filterbull Draw and label a frequency response curvebull Draw and differentiate different types of acoustic
filtersbull Define terms such as cutoff frequency center
frequency roll off rate gain and bandwidthbull Define and draw a basic filter system and relate that
to the source-filter theory of speech production
What is an ldquoAcousticrdquo Filter
bull holds back (attenuates) certain sounds and lets other sounds through - selective
Why might we be interested in filters
bull Human vocal tract acts like a frequency selective acoustic filter
bull Human auditory system behaves as a frequency selective filter
bull helps us understand how speech is produced and perceived
Kinds of frequency selective filters
Low-pass filtersndash Lets low frequencies ldquopass throughrdquo and attenuates high
frequencies
High-pass filtersndash Lets high frequencies ldquopass throughrdquo and attenuates low
frequencies
Band-pass filtersndash Lets a particular frequency range ldquopass throughrdquo and
attenuates other frequencies
Low Pass Filters
Frequencylow high
Gai
n
+
-
High Pass Filters
Frequencylow high
Gai
n
+
-
Band Pass Filter
Frequencylow high
Gai
n
+
-
Frequency Response Curve (FRC)
Frequencylow high
Gai
n
+
-
Center frequency
lower cutofffrequency
upper cutoff frequency
passband
3 dB
Operation of a filter on a signal
NOTE Amplitude spectrum describes a soundFrequency response curve describes a filter
Learning Objectivesbull Define resonance free and forced vibrationbull Describe how the pendulum and spring mass models can
help explain resonancebull Outline how mass and stiffness influences the resonant
frequency of a mass spring systembull Outline how acoustic resonators behave like acoustic filtersbull Calculate resonant frequencies of a uniform tube based on
its physical dimensionsbull Describe how the wavelength of the sound determines the
resonant frequency of tube
Free vibration
bull objects tend to vibrate at a characteristic or resonant frequency (RF)
Forced vibration
bull A vibrating system can force a nearby system into vibration
bull The efficiency with which this is accomplished is related to the similarity in the resonant frequency (RF) of the two systems
Forced vibration
bull If the RF of the two systems are the same the amplitude of forced vibration will be large
bull If the RF of the two systems are quite different the amplitude of forced vibration will be small or nonexistent
Resonance refers to
bull The tendency for an object to vibrate at a particular frequency or frequencies
bull The ability of a vibrating system to force another system into vibration
Back to the mass spring model
bull Vibratory frequency of the mass spring determined byndash Massndash Stiffness of the spring
httpphetcoloradoeduensimulationmass-spring-lab
Acoustic Resonance
bull Ideas from mechanical resonance also applies to acoustic systems
bull Acoustic chambers will transmit sound frequencies with more or less efficiency depending upon the physical characteristics
bull Therefore they act as filters passing through (and even amplifying) some frequencies and attentuating others
Acoustic Resonance
bull And since they act as filters they have most of the same features of a filter even though we might use different names
bull Center frequency is often termed the resonant frequency
bull Frequency response curve often termed the resonance curve
Helmholtz Resonator
Actions of a Helmholtz Resonator
Stephen M Tasko
Other Acoustic Resonators Tube Resonators
bull Uniform tubes Factors that influence resonancendash Lengthndash Cross-sectional area along its lengthndash Whether it is closed at either or both ends
Uniform tube closed at one end
Uniform tube closed at one end
Stephen M Tasko
Uniform tube closed at one end
First resonance or formant
F1 = c4lWhere
c=speed of sound (35000 cmsec)l = length of the tube
males ~ 175 cmfemales ~ 14 cm
Higher resonantformant frequencies are odd multiples of F1
For examplebull F1 = (c4l )1
bull F2 = (c4l )3
bull F3 = (c4l )5
Comparing Helmholtz and tube resonators
Resonator Features
Sharply tuned Broadly tuned
Resonator Features
An example of the resonance characteristics of the human vocal tract
Frequency
Gain
SPPA 4030 Speech Science
Topic 1 The Speech Chain
The Speech Chain (Denes amp Pinson 1993)
What information is embedded in the speech signal
Branches of science employed to understand speech communication
Physical Quantities Review An Independent Learning Activity
Assignment 1
Topic 2 The Source-Filter Theory of Speech Production An Intr
Producing Speech
Source-Filter Theory of Speech Production
Vocal tract is a tube that can vary its shape
Source Filter Theory
Same Source Different Filter
Different Source Same Filters
Different Source Same Filters (Human)
Different Source Same Filters (Human) (2)
Different Source Same Filters (Human) (3)
Different Source Same Filters (Human) (4)
Different Source Same Filters (Non-Human)
Different Source Same Filters (Non-Human) (2)
Different Source Same Filters (Non-Human) If it quacks like a
Source Filter Theory Applied Alaryngeal Speech
Source-Filter Theory Applied Esophageal Insufflation Test
Source-Filter Theory Applied Tracheoesophageal (TE) Speech
Source Filter Theory Applied The Talkbox
Source-Filter Theory Applied The Talkbox
Topic 3 A Brief Review of Physical Acoustics
Spring Mass Model
What is sound
Sound-conducting media
Model of air molecule vibration (Time 1)
Model of air molecule vibration (Time 2)
Model of air molecule vibration (Time 3)
Model of air molecule vibration (Time 4)
Model of air molecule vibration (Time 5)
Model of air molecule vibration
Wave action of molecular motion
Amplitude waveform
Amplitude waveform (2)
Where is pressure in this model
Pressure waveform
Measuring Sound
Measuring Sound Signal Amplitude
Measuring Sound Signal Amplitude (2)
What units do we use to measure signal amplitude
Brief Review The decibel scale
Absolute vs relative measurement
Typical reference values
Howeverhellip
Linear vs logarithmic
Linear vs logarithmic (2)
Logarithmic Scale
Logarithmic Scale (2)
Combining the idea of logarithmic and relativehellip
Intensity vs Pressure
Extending the formula to pressure
Measuring Sound Frequencyperiod
Measuring Sound Frequencyperiod (2)
Phase Uniform Circular Motion
Initiating a sound waves that differ only in phase
Spatial variation in pressure wave
Spatial variation in pressure wave
Spatial variation in pressure wave (2)
Relation between frequency and wavelength
Learning Objectives
Graphic representation of sound
Same sound different graphs
Classification of sounds
Simple periodic sound
Simple periodic sound Graphic appearance
Complex periodic sounds
Complex periodic sounds Graphic appearance
Complex periodic sounds Graphic appearance (2)
Glottal Source
Amplitude vs Phase Spectrum
Amplitude vs Phase Spectrum (2)
(Complex) Aperiodic sounds
Aperiodic sounds Graphic appearance
Aperiodic sounds Graphic appearance (2)
Analysis of complex waves
Learning Objectives (2)
The ldquoenveloperdquo of a sound wave
Waveform envelope
Waveform envelope (2)
Spectrum envelope
Thought Question
Amplitude Spectrum Window Size
ldquoInstantaneousrdquo Amplitude Spectra
(Long Term) Average Amplitude Spectrum
Slide 90
Learning Objectives (3)
The Spectrogram
Building a spectrogram
Building a spectrogram
Building a spectrogram (2)
Two main types of spectrograms
Wide vs Narrow Band Spectrograms
Learning Objectives (4)
What is an ldquoAcousticrdquo Filter
Why might we be interested in filters
Kinds of frequency selective filters
Low Pass Filters
High Pass Filters
Band Pass Filter
Frequency Response Curve (FRC)
Operation of a filter on a signal
Learning Objectives (5)
Free vibration
Forced vibration
Forced vibration (2)
Resonance refers to
Back to the mass spring model
Acoustic Resonance
Acoustic Resonance (2)
Helmholtz Resonator
Actions of a Helmholtz Resonator
Other Acoustic Resonators Tube Resonators
Uniform tube closed at one end
Uniform tube closed at one end (2)
Uniform tube closed at one end
Comparing Helmholtz and tube resonators
Slide 122
Slide 123
Dark bands= amplitudePeaks
Time
Freq
uenc
y
Building a spectrogram
Two main types of spectrograms
bull Narrow-band spectrogramsndash Akin to amplitude spectrums ldquolined uprdquondash Frequency resolution is really sharp
bull Wide-band spectrogramsndash Akin to spectrum envelopes ldquolined uprdquondash Frequency resolution not so sharp
Highlights harmonic structure
Highlights spectrum envelope
Wide vs Narrow Band Spectrograms
Learning Objectives
bull Define an acoustic filterbull Draw and label a frequency response curvebull Draw and differentiate different types of acoustic
filtersbull Define terms such as cutoff frequency center
frequency roll off rate gain and bandwidthbull Define and draw a basic filter system and relate that
to the source-filter theory of speech production
What is an ldquoAcousticrdquo Filter
bull holds back (attenuates) certain sounds and lets other sounds through - selective
Why might we be interested in filters
bull Human vocal tract acts like a frequency selective acoustic filter
bull Human auditory system behaves as a frequency selective filter
bull helps us understand how speech is produced and perceived
Kinds of frequency selective filters
Low-pass filtersndash Lets low frequencies ldquopass throughrdquo and attenuates high
frequencies
High-pass filtersndash Lets high frequencies ldquopass throughrdquo and attenuates low
frequencies
Band-pass filtersndash Lets a particular frequency range ldquopass throughrdquo and
attenuates other frequencies
Low Pass Filters
Frequencylow high
Gai
n
+
-
High Pass Filters
Frequencylow high
Gai
n
+
-
Band Pass Filter
Frequencylow high
Gai
n
+
-
Frequency Response Curve (FRC)
Frequencylow high
Gai
n
+
-
Center frequency
lower cutofffrequency
upper cutoff frequency
passband
3 dB
Operation of a filter on a signal
NOTE Amplitude spectrum describes a soundFrequency response curve describes a filter
Learning Objectivesbull Define resonance free and forced vibrationbull Describe how the pendulum and spring mass models can
help explain resonancebull Outline how mass and stiffness influences the resonant
frequency of a mass spring systembull Outline how acoustic resonators behave like acoustic filtersbull Calculate resonant frequencies of a uniform tube based on
its physical dimensionsbull Describe how the wavelength of the sound determines the
resonant frequency of tube
Free vibration
bull objects tend to vibrate at a characteristic or resonant frequency (RF)
Forced vibration
bull A vibrating system can force a nearby system into vibration
bull The efficiency with which this is accomplished is related to the similarity in the resonant frequency (RF) of the two systems
Forced vibration
bull If the RF of the two systems are the same the amplitude of forced vibration will be large
bull If the RF of the two systems are quite different the amplitude of forced vibration will be small or nonexistent
Resonance refers to
bull The tendency for an object to vibrate at a particular frequency or frequencies
bull The ability of a vibrating system to force another system into vibration
Back to the mass spring model
bull Vibratory frequency of the mass spring determined byndash Massndash Stiffness of the spring
httpphetcoloradoeduensimulationmass-spring-lab
Acoustic Resonance
bull Ideas from mechanical resonance also applies to acoustic systems
bull Acoustic chambers will transmit sound frequencies with more or less efficiency depending upon the physical characteristics
bull Therefore they act as filters passing through (and even amplifying) some frequencies and attentuating others
Acoustic Resonance
bull And since they act as filters they have most of the same features of a filter even though we might use different names
bull Center frequency is often termed the resonant frequency
bull Frequency response curve often termed the resonance curve
Helmholtz Resonator
Actions of a Helmholtz Resonator
Stephen M Tasko
Other Acoustic Resonators Tube Resonators
bull Uniform tubes Factors that influence resonancendash Lengthndash Cross-sectional area along its lengthndash Whether it is closed at either or both ends
Uniform tube closed at one end
Uniform tube closed at one end
Stephen M Tasko
Uniform tube closed at one end
First resonance or formant
F1 = c4lWhere
c=speed of sound (35000 cmsec)l = length of the tube
males ~ 175 cmfemales ~ 14 cm
Higher resonantformant frequencies are odd multiples of F1
For examplebull F1 = (c4l )1
bull F2 = (c4l )3
bull F3 = (c4l )5
Comparing Helmholtz and tube resonators
Resonator Features
Sharply tuned Broadly tuned
Resonator Features
An example of the resonance characteristics of the human vocal tract
Frequency
Gain
SPPA 4030 Speech Science
Topic 1 The Speech Chain
The Speech Chain (Denes amp Pinson 1993)
What information is embedded in the speech signal
Branches of science employed to understand speech communication
Physical Quantities Review An Independent Learning Activity
Assignment 1
Topic 2 The Source-Filter Theory of Speech Production An Intr
Producing Speech
Source-Filter Theory of Speech Production
Vocal tract is a tube that can vary its shape
Source Filter Theory
Same Source Different Filter
Different Source Same Filters
Different Source Same Filters (Human)
Different Source Same Filters (Human) (2)
Different Source Same Filters (Human) (3)
Different Source Same Filters (Human) (4)
Different Source Same Filters (Non-Human)
Different Source Same Filters (Non-Human) (2)
Different Source Same Filters (Non-Human) If it quacks like a
Source Filter Theory Applied Alaryngeal Speech
Source-Filter Theory Applied Esophageal Insufflation Test
Source-Filter Theory Applied Tracheoesophageal (TE) Speech
Source Filter Theory Applied The Talkbox
Source-Filter Theory Applied The Talkbox
Topic 3 A Brief Review of Physical Acoustics
Spring Mass Model
What is sound
Sound-conducting media
Model of air molecule vibration (Time 1)
Model of air molecule vibration (Time 2)
Model of air molecule vibration (Time 3)
Model of air molecule vibration (Time 4)
Model of air molecule vibration (Time 5)
Model of air molecule vibration
Wave action of molecular motion
Amplitude waveform
Amplitude waveform (2)
Where is pressure in this model
Pressure waveform
Measuring Sound
Measuring Sound Signal Amplitude
Measuring Sound Signal Amplitude (2)
What units do we use to measure signal amplitude
Brief Review The decibel scale
Absolute vs relative measurement
Typical reference values
Howeverhellip
Linear vs logarithmic
Linear vs logarithmic (2)
Logarithmic Scale
Logarithmic Scale (2)
Combining the idea of logarithmic and relativehellip
Intensity vs Pressure
Extending the formula to pressure
Measuring Sound Frequencyperiod
Measuring Sound Frequencyperiod (2)
Phase Uniform Circular Motion
Initiating a sound waves that differ only in phase
Spatial variation in pressure wave
Spatial variation in pressure wave
Spatial variation in pressure wave (2)
Relation between frequency and wavelength
Learning Objectives
Graphic representation of sound
Same sound different graphs
Classification of sounds
Simple periodic sound
Simple periodic sound Graphic appearance
Complex periodic sounds
Complex periodic sounds Graphic appearance
Complex periodic sounds Graphic appearance (2)
Glottal Source
Amplitude vs Phase Spectrum
Amplitude vs Phase Spectrum (2)
(Complex) Aperiodic sounds
Aperiodic sounds Graphic appearance
Aperiodic sounds Graphic appearance (2)
Analysis of complex waves
Learning Objectives (2)
The ldquoenveloperdquo of a sound wave
Waveform envelope
Waveform envelope (2)
Spectrum envelope
Thought Question
Amplitude Spectrum Window Size
ldquoInstantaneousrdquo Amplitude Spectra
(Long Term) Average Amplitude Spectrum
Slide 90
Learning Objectives (3)
The Spectrogram
Building a spectrogram
Building a spectrogram
Building a spectrogram (2)
Two main types of spectrograms
Wide vs Narrow Band Spectrograms
Learning Objectives (4)
What is an ldquoAcousticrdquo Filter
Why might we be interested in filters
Kinds of frequency selective filters
Low Pass Filters
High Pass Filters
Band Pass Filter
Frequency Response Curve (FRC)
Operation of a filter on a signal
Learning Objectives (5)
Free vibration
Forced vibration
Forced vibration (2)
Resonance refers to
Back to the mass spring model
Acoustic Resonance
Acoustic Resonance (2)
Helmholtz Resonator
Actions of a Helmholtz Resonator
Other Acoustic Resonators Tube Resonators
Uniform tube closed at one end
Uniform tube closed at one end (2)
Uniform tube closed at one end
Comparing Helmholtz and tube resonators
Slide 122
Slide 123
Two main types of spectrograms
bull Narrow-band spectrogramsndash Akin to amplitude spectrums ldquolined uprdquondash Frequency resolution is really sharp
bull Wide-band spectrogramsndash Akin to spectrum envelopes ldquolined uprdquondash Frequency resolution not so sharp
Highlights harmonic structure
Highlights spectrum envelope
Wide vs Narrow Band Spectrograms
Learning Objectives
bull Define an acoustic filterbull Draw and label a frequency response curvebull Draw and differentiate different types of acoustic
filtersbull Define terms such as cutoff frequency center
frequency roll off rate gain and bandwidthbull Define and draw a basic filter system and relate that
to the source-filter theory of speech production
What is an ldquoAcousticrdquo Filter
bull holds back (attenuates) certain sounds and lets other sounds through - selective
Why might we be interested in filters
bull Human vocal tract acts like a frequency selective acoustic filter
bull Human auditory system behaves as a frequency selective filter
bull helps us understand how speech is produced and perceived
Kinds of frequency selective filters
Low-pass filtersndash Lets low frequencies ldquopass throughrdquo and attenuates high
frequencies
High-pass filtersndash Lets high frequencies ldquopass throughrdquo and attenuates low
frequencies
Band-pass filtersndash Lets a particular frequency range ldquopass throughrdquo and
attenuates other frequencies
Low Pass Filters
Frequencylow high
Gai
n
+
-
High Pass Filters
Frequencylow high
Gai
n
+
-
Band Pass Filter
Frequencylow high
Gai
n
+
-
Frequency Response Curve (FRC)
Frequencylow high
Gai
n
+
-
Center frequency
lower cutofffrequency
upper cutoff frequency
passband
3 dB
Operation of a filter on a signal
NOTE Amplitude spectrum describes a soundFrequency response curve describes a filter
Learning Objectivesbull Define resonance free and forced vibrationbull Describe how the pendulum and spring mass models can
help explain resonancebull Outline how mass and stiffness influences the resonant
frequency of a mass spring systembull Outline how acoustic resonators behave like acoustic filtersbull Calculate resonant frequencies of a uniform tube based on
its physical dimensionsbull Describe how the wavelength of the sound determines the
resonant frequency of tube
Free vibration
bull objects tend to vibrate at a characteristic or resonant frequency (RF)
Forced vibration
bull A vibrating system can force a nearby system into vibration
bull The efficiency with which this is accomplished is related to the similarity in the resonant frequency (RF) of the two systems
Forced vibration
bull If the RF of the two systems are the same the amplitude of forced vibration will be large
bull If the RF of the two systems are quite different the amplitude of forced vibration will be small or nonexistent
Resonance refers to
bull The tendency for an object to vibrate at a particular frequency or frequencies
bull The ability of a vibrating system to force another system into vibration
Back to the mass spring model
bull Vibratory frequency of the mass spring determined byndash Massndash Stiffness of the spring
httpphetcoloradoeduensimulationmass-spring-lab
Acoustic Resonance
bull Ideas from mechanical resonance also applies to acoustic systems
bull Acoustic chambers will transmit sound frequencies with more or less efficiency depending upon the physical characteristics
bull Therefore they act as filters passing through (and even amplifying) some frequencies and attentuating others
Acoustic Resonance
bull And since they act as filters they have most of the same features of a filter even though we might use different names
bull Center frequency is often termed the resonant frequency
bull Frequency response curve often termed the resonance curve
Helmholtz Resonator
Actions of a Helmholtz Resonator
Stephen M Tasko
Other Acoustic Resonators Tube Resonators
bull Uniform tubes Factors that influence resonancendash Lengthndash Cross-sectional area along its lengthndash Whether it is closed at either or both ends
Uniform tube closed at one end
Uniform tube closed at one end
Stephen M Tasko
Uniform tube closed at one end
First resonance or formant
F1 = c4lWhere
c=speed of sound (35000 cmsec)l = length of the tube
males ~ 175 cmfemales ~ 14 cm
Higher resonantformant frequencies are odd multiples of F1
For examplebull F1 = (c4l )1
bull F2 = (c4l )3
bull F3 = (c4l )5
Comparing Helmholtz and tube resonators
Resonator Features
Sharply tuned Broadly tuned
Resonator Features
An example of the resonance characteristics of the human vocal tract
Frequency
Gain
SPPA 4030 Speech Science
Topic 1 The Speech Chain
The Speech Chain (Denes amp Pinson 1993)
What information is embedded in the speech signal
Branches of science employed to understand speech communication
Physical Quantities Review An Independent Learning Activity
Assignment 1
Topic 2 The Source-Filter Theory of Speech Production An Intr
Producing Speech
Source-Filter Theory of Speech Production
Vocal tract is a tube that can vary its shape
Source Filter Theory
Same Source Different Filter
Different Source Same Filters
Different Source Same Filters (Human)
Different Source Same Filters (Human) (2)
Different Source Same Filters (Human) (3)
Different Source Same Filters (Human) (4)
Different Source Same Filters (Non-Human)
Different Source Same Filters (Non-Human) (2)
Different Source Same Filters (Non-Human) If it quacks like a
Source Filter Theory Applied Alaryngeal Speech
Source-Filter Theory Applied Esophageal Insufflation Test
Source-Filter Theory Applied Tracheoesophageal (TE) Speech
Source Filter Theory Applied The Talkbox
Source-Filter Theory Applied The Talkbox
Topic 3 A Brief Review of Physical Acoustics
Spring Mass Model
What is sound
Sound-conducting media
Model of air molecule vibration (Time 1)
Model of air molecule vibration (Time 2)
Model of air molecule vibration (Time 3)
Model of air molecule vibration (Time 4)
Model of air molecule vibration (Time 5)
Model of air molecule vibration
Wave action of molecular motion
Amplitude waveform
Amplitude waveform (2)
Where is pressure in this model
Pressure waveform
Measuring Sound
Measuring Sound Signal Amplitude
Measuring Sound Signal Amplitude (2)
What units do we use to measure signal amplitude
Brief Review The decibel scale
Absolute vs relative measurement
Typical reference values
Howeverhellip
Linear vs logarithmic
Linear vs logarithmic (2)
Logarithmic Scale
Logarithmic Scale (2)
Combining the idea of logarithmic and relativehellip
Intensity vs Pressure
Extending the formula to pressure
Measuring Sound Frequencyperiod
Measuring Sound Frequencyperiod (2)
Phase Uniform Circular Motion
Initiating a sound waves that differ only in phase
Spatial variation in pressure wave
Spatial variation in pressure wave
Spatial variation in pressure wave (2)
Relation between frequency and wavelength
Learning Objectives
Graphic representation of sound
Same sound different graphs
Classification of sounds
Simple periodic sound
Simple periodic sound Graphic appearance
Complex periodic sounds
Complex periodic sounds Graphic appearance
Complex periodic sounds Graphic appearance (2)
Glottal Source
Amplitude vs Phase Spectrum
Amplitude vs Phase Spectrum (2)
(Complex) Aperiodic sounds
Aperiodic sounds Graphic appearance
Aperiodic sounds Graphic appearance (2)
Analysis of complex waves
Learning Objectives (2)
The ldquoenveloperdquo of a sound wave
Waveform envelope
Waveform envelope (2)
Spectrum envelope
Thought Question
Amplitude Spectrum Window Size
ldquoInstantaneousrdquo Amplitude Spectra
(Long Term) Average Amplitude Spectrum
Slide 90
Learning Objectives (3)
The Spectrogram
Building a spectrogram
Building a spectrogram
Building a spectrogram (2)
Two main types of spectrograms
Wide vs Narrow Band Spectrograms
Learning Objectives (4)
What is an ldquoAcousticrdquo Filter
Why might we be interested in filters
Kinds of frequency selective filters
Low Pass Filters
High Pass Filters
Band Pass Filter
Frequency Response Curve (FRC)
Operation of a filter on a signal
Learning Objectives (5)
Free vibration
Forced vibration
Forced vibration (2)
Resonance refers to
Back to the mass spring model
Acoustic Resonance
Acoustic Resonance (2)
Helmholtz Resonator
Actions of a Helmholtz Resonator
Other Acoustic Resonators Tube Resonators
Uniform tube closed at one end
Uniform tube closed at one end (2)
Uniform tube closed at one end
Comparing Helmholtz and tube resonators
Slide 122
Slide 123
Highlights harmonic structure
Highlights spectrum envelope
Wide vs Narrow Band Spectrograms
Learning Objectives
bull Define an acoustic filterbull Draw and label a frequency response curvebull Draw and differentiate different types of acoustic
filtersbull Define terms such as cutoff frequency center
frequency roll off rate gain and bandwidthbull Define and draw a basic filter system and relate that
to the source-filter theory of speech production
What is an ldquoAcousticrdquo Filter
bull holds back (attenuates) certain sounds and lets other sounds through - selective
Why might we be interested in filters
bull Human vocal tract acts like a frequency selective acoustic filter
bull Human auditory system behaves as a frequency selective filter
bull helps us understand how speech is produced and perceived
Kinds of frequency selective filters
Low-pass filtersndash Lets low frequencies ldquopass throughrdquo and attenuates high
frequencies
High-pass filtersndash Lets high frequencies ldquopass throughrdquo and attenuates low
frequencies
Band-pass filtersndash Lets a particular frequency range ldquopass throughrdquo and
attenuates other frequencies
Low Pass Filters
Frequencylow high
Gai
n
+
-
High Pass Filters
Frequencylow high
Gai
n
+
-
Band Pass Filter
Frequencylow high
Gai
n
+
-
Frequency Response Curve (FRC)
Frequencylow high
Gai
n
+
-
Center frequency
lower cutofffrequency
upper cutoff frequency
passband
3 dB
Operation of a filter on a signal
NOTE Amplitude spectrum describes a soundFrequency response curve describes a filter
Learning Objectivesbull Define resonance free and forced vibrationbull Describe how the pendulum and spring mass models can
help explain resonancebull Outline how mass and stiffness influences the resonant
frequency of a mass spring systembull Outline how acoustic resonators behave like acoustic filtersbull Calculate resonant frequencies of a uniform tube based on
its physical dimensionsbull Describe how the wavelength of the sound determines the
resonant frequency of tube
Free vibration
bull objects tend to vibrate at a characteristic or resonant frequency (RF)
Forced vibration
bull A vibrating system can force a nearby system into vibration
bull The efficiency with which this is accomplished is related to the similarity in the resonant frequency (RF) of the two systems
Forced vibration
bull If the RF of the two systems are the same the amplitude of forced vibration will be large
bull If the RF of the two systems are quite different the amplitude of forced vibration will be small or nonexistent
Resonance refers to
bull The tendency for an object to vibrate at a particular frequency or frequencies
bull The ability of a vibrating system to force another system into vibration
Back to the mass spring model
bull Vibratory frequency of the mass spring determined byndash Massndash Stiffness of the spring
httpphetcoloradoeduensimulationmass-spring-lab
Acoustic Resonance
bull Ideas from mechanical resonance also applies to acoustic systems
bull Acoustic chambers will transmit sound frequencies with more or less efficiency depending upon the physical characteristics
bull Therefore they act as filters passing through (and even amplifying) some frequencies and attentuating others
Acoustic Resonance
bull And since they act as filters they have most of the same features of a filter even though we might use different names
bull Center frequency is often termed the resonant frequency
bull Frequency response curve often termed the resonance curve
Helmholtz Resonator
Actions of a Helmholtz Resonator
Stephen M Tasko
Other Acoustic Resonators Tube Resonators
bull Uniform tubes Factors that influence resonancendash Lengthndash Cross-sectional area along its lengthndash Whether it is closed at either or both ends
Uniform tube closed at one end
Uniform tube closed at one end
Stephen M Tasko
Uniform tube closed at one end
First resonance or formant
F1 = c4lWhere
c=speed of sound (35000 cmsec)l = length of the tube
males ~ 175 cmfemales ~ 14 cm
Higher resonantformant frequencies are odd multiples of F1
For examplebull F1 = (c4l )1
bull F2 = (c4l )3
bull F3 = (c4l )5
Comparing Helmholtz and tube resonators
Resonator Features
Sharply tuned Broadly tuned
Resonator Features
An example of the resonance characteristics of the human vocal tract
Frequency
Gain
SPPA 4030 Speech Science
Topic 1 The Speech Chain
The Speech Chain (Denes amp Pinson 1993)
What information is embedded in the speech signal
Branches of science employed to understand speech communication
Physical Quantities Review An Independent Learning Activity
Assignment 1
Topic 2 The Source-Filter Theory of Speech Production An Intr
Producing Speech
Source-Filter Theory of Speech Production
Vocal tract is a tube that can vary its shape
Source Filter Theory
Same Source Different Filter
Different Source Same Filters
Different Source Same Filters (Human)
Different Source Same Filters (Human) (2)
Different Source Same Filters (Human) (3)
Different Source Same Filters (Human) (4)
Different Source Same Filters (Non-Human)
Different Source Same Filters (Non-Human) (2)
Different Source Same Filters (Non-Human) If it quacks like a
Source Filter Theory Applied Alaryngeal Speech
Source-Filter Theory Applied Esophageal Insufflation Test
Source-Filter Theory Applied Tracheoesophageal (TE) Speech
Source Filter Theory Applied The Talkbox
Source-Filter Theory Applied The Talkbox
Topic 3 A Brief Review of Physical Acoustics
Spring Mass Model
What is sound
Sound-conducting media
Model of air molecule vibration (Time 1)
Model of air molecule vibration (Time 2)
Model of air molecule vibration (Time 3)
Model of air molecule vibration (Time 4)
Model of air molecule vibration (Time 5)
Model of air molecule vibration
Wave action of molecular motion
Amplitude waveform
Amplitude waveform (2)
Where is pressure in this model
Pressure waveform
Measuring Sound
Measuring Sound Signal Amplitude
Measuring Sound Signal Amplitude (2)
What units do we use to measure signal amplitude
Brief Review The decibel scale
Absolute vs relative measurement
Typical reference values
Howeverhellip
Linear vs logarithmic
Linear vs logarithmic (2)
Logarithmic Scale
Logarithmic Scale (2)
Combining the idea of logarithmic and relativehellip
Intensity vs Pressure
Extending the formula to pressure
Measuring Sound Frequencyperiod
Measuring Sound Frequencyperiod (2)
Phase Uniform Circular Motion
Initiating a sound waves that differ only in phase
Spatial variation in pressure wave
Spatial variation in pressure wave
Spatial variation in pressure wave (2)
Relation between frequency and wavelength
Learning Objectives
Graphic representation of sound
Same sound different graphs
Classification of sounds
Simple periodic sound
Simple periodic sound Graphic appearance
Complex periodic sounds
Complex periodic sounds Graphic appearance
Complex periodic sounds Graphic appearance (2)
Glottal Source
Amplitude vs Phase Spectrum
Amplitude vs Phase Spectrum (2)
(Complex) Aperiodic sounds
Aperiodic sounds Graphic appearance
Aperiodic sounds Graphic appearance (2)
Analysis of complex waves
Learning Objectives (2)
The ldquoenveloperdquo of a sound wave
Waveform envelope
Waveform envelope (2)
Spectrum envelope
Thought Question
Amplitude Spectrum Window Size
ldquoInstantaneousrdquo Amplitude Spectra
(Long Term) Average Amplitude Spectrum
Slide 90
Learning Objectives (3)
The Spectrogram
Building a spectrogram
Building a spectrogram
Building a spectrogram (2)
Two main types of spectrograms
Wide vs Narrow Band Spectrograms
Learning Objectives (4)
What is an ldquoAcousticrdquo Filter
Why might we be interested in filters
Kinds of frequency selective filters
Low Pass Filters
High Pass Filters
Band Pass Filter
Frequency Response Curve (FRC)
Operation of a filter on a signal
Learning Objectives (5)
Free vibration
Forced vibration
Forced vibration (2)
Resonance refers to
Back to the mass spring model
Acoustic Resonance
Acoustic Resonance (2)
Helmholtz Resonator
Actions of a Helmholtz Resonator
Other Acoustic Resonators Tube Resonators
Uniform tube closed at one end
Uniform tube closed at one end (2)
Uniform tube closed at one end
Comparing Helmholtz and tube resonators
Slide 122
Slide 123
Learning Objectives
bull Define an acoustic filterbull Draw and label a frequency response curvebull Draw and differentiate different types of acoustic
filtersbull Define terms such as cutoff frequency center
frequency roll off rate gain and bandwidthbull Define and draw a basic filter system and relate that
to the source-filter theory of speech production
What is an ldquoAcousticrdquo Filter
bull holds back (attenuates) certain sounds and lets other sounds through - selective
Why might we be interested in filters
bull Human vocal tract acts like a frequency selective acoustic filter
bull Human auditory system behaves as a frequency selective filter
bull helps us understand how speech is produced and perceived
Kinds of frequency selective filters
Low-pass filtersndash Lets low frequencies ldquopass throughrdquo and attenuates high
frequencies
High-pass filtersndash Lets high frequencies ldquopass throughrdquo and attenuates low
frequencies
Band-pass filtersndash Lets a particular frequency range ldquopass throughrdquo and
attenuates other frequencies
Low Pass Filters
Frequencylow high
Gai
n
+
-
High Pass Filters
Frequencylow high
Gai
n
+
-
Band Pass Filter
Frequencylow high
Gai
n
+
-
Frequency Response Curve (FRC)
Frequencylow high
Gai
n
+
-
Center frequency
lower cutofffrequency
upper cutoff frequency
passband
3 dB
Operation of a filter on a signal
NOTE Amplitude spectrum describes a soundFrequency response curve describes a filter
Learning Objectivesbull Define resonance free and forced vibrationbull Describe how the pendulum and spring mass models can
help explain resonancebull Outline how mass and stiffness influences the resonant
frequency of a mass spring systembull Outline how acoustic resonators behave like acoustic filtersbull Calculate resonant frequencies of a uniform tube based on
its physical dimensionsbull Describe how the wavelength of the sound determines the
resonant frequency of tube
Free vibration
bull objects tend to vibrate at a characteristic or resonant frequency (RF)
Forced vibration
bull A vibrating system can force a nearby system into vibration
bull The efficiency with which this is accomplished is related to the similarity in the resonant frequency (RF) of the two systems
Forced vibration
bull If the RF of the two systems are the same the amplitude of forced vibration will be large
bull If the RF of the two systems are quite different the amplitude of forced vibration will be small or nonexistent
Resonance refers to
bull The tendency for an object to vibrate at a particular frequency or frequencies
bull The ability of a vibrating system to force another system into vibration
Back to the mass spring model
bull Vibratory frequency of the mass spring determined byndash Massndash Stiffness of the spring
httpphetcoloradoeduensimulationmass-spring-lab
Acoustic Resonance
bull Ideas from mechanical resonance also applies to acoustic systems
bull Acoustic chambers will transmit sound frequencies with more or less efficiency depending upon the physical characteristics
bull Therefore they act as filters passing through (and even amplifying) some frequencies and attentuating others
Acoustic Resonance
bull And since they act as filters they have most of the same features of a filter even though we might use different names
bull Center frequency is often termed the resonant frequency
bull Frequency response curve often termed the resonance curve
Helmholtz Resonator
Actions of a Helmholtz Resonator
Stephen M Tasko
Other Acoustic Resonators Tube Resonators
bull Uniform tubes Factors that influence resonancendash Lengthndash Cross-sectional area along its lengthndash Whether it is closed at either or both ends
Uniform tube closed at one end
Uniform tube closed at one end
Stephen M Tasko
Uniform tube closed at one end
First resonance or formant
F1 = c4lWhere
c=speed of sound (35000 cmsec)l = length of the tube
males ~ 175 cmfemales ~ 14 cm
Higher resonantformant frequencies are odd multiples of F1
For examplebull F1 = (c4l )1
bull F2 = (c4l )3
bull F3 = (c4l )5
Comparing Helmholtz and tube resonators
Resonator Features
Sharply tuned Broadly tuned
Resonator Features
An example of the resonance characteristics of the human vocal tract
Frequency
Gain
SPPA 4030 Speech Science
Topic 1 The Speech Chain
The Speech Chain (Denes amp Pinson 1993)
What information is embedded in the speech signal
Branches of science employed to understand speech communication
Physical Quantities Review An Independent Learning Activity
Assignment 1
Topic 2 The Source-Filter Theory of Speech Production An Intr
Producing Speech
Source-Filter Theory of Speech Production
Vocal tract is a tube that can vary its shape
Source Filter Theory
Same Source Different Filter
Different Source Same Filters
Different Source Same Filters (Human)
Different Source Same Filters (Human) (2)
Different Source Same Filters (Human) (3)
Different Source Same Filters (Human) (4)
Different Source Same Filters (Non-Human)
Different Source Same Filters (Non-Human) (2)
Different Source Same Filters (Non-Human) If it quacks like a
Source Filter Theory Applied Alaryngeal Speech
Source-Filter Theory Applied Esophageal Insufflation Test
Source-Filter Theory Applied Tracheoesophageal (TE) Speech
Source Filter Theory Applied The Talkbox
Source-Filter Theory Applied The Talkbox
Topic 3 A Brief Review of Physical Acoustics
Spring Mass Model
What is sound
Sound-conducting media
Model of air molecule vibration (Time 1)
Model of air molecule vibration (Time 2)
Model of air molecule vibration (Time 3)
Model of air molecule vibration (Time 4)
Model of air molecule vibration (Time 5)
Model of air molecule vibration
Wave action of molecular motion
Amplitude waveform
Amplitude waveform (2)
Where is pressure in this model
Pressure waveform
Measuring Sound
Measuring Sound Signal Amplitude
Measuring Sound Signal Amplitude (2)
What units do we use to measure signal amplitude
Brief Review The decibel scale
Absolute vs relative measurement
Typical reference values
Howeverhellip
Linear vs logarithmic
Linear vs logarithmic (2)
Logarithmic Scale
Logarithmic Scale (2)
Combining the idea of logarithmic and relativehellip
Intensity vs Pressure
Extending the formula to pressure
Measuring Sound Frequencyperiod
Measuring Sound Frequencyperiod (2)
Phase Uniform Circular Motion
Initiating a sound waves that differ only in phase
Spatial variation in pressure wave
Spatial variation in pressure wave
Spatial variation in pressure wave (2)
Relation between frequency and wavelength
Learning Objectives
Graphic representation of sound
Same sound different graphs
Classification of sounds
Simple periodic sound
Simple periodic sound Graphic appearance
Complex periodic sounds
Complex periodic sounds Graphic appearance
Complex periodic sounds Graphic appearance (2)
Glottal Source
Amplitude vs Phase Spectrum
Amplitude vs Phase Spectrum (2)
(Complex) Aperiodic sounds
Aperiodic sounds Graphic appearance
Aperiodic sounds Graphic appearance (2)
Analysis of complex waves
Learning Objectives (2)
The ldquoenveloperdquo of a sound wave
Waveform envelope
Waveform envelope (2)
Spectrum envelope
Thought Question
Amplitude Spectrum Window Size
ldquoInstantaneousrdquo Amplitude Spectra
(Long Term) Average Amplitude Spectrum
Slide 90
Learning Objectives (3)
The Spectrogram
Building a spectrogram
Building a spectrogram
Building a spectrogram (2)
Two main types of spectrograms
Wide vs Narrow Band Spectrograms
Learning Objectives (4)
What is an ldquoAcousticrdquo Filter
Why might we be interested in filters
Kinds of frequency selective filters
Low Pass Filters
High Pass Filters
Band Pass Filter
Frequency Response Curve (FRC)
Operation of a filter on a signal
Learning Objectives (5)
Free vibration
Forced vibration
Forced vibration (2)
Resonance refers to
Back to the mass spring model
Acoustic Resonance
Acoustic Resonance (2)
Helmholtz Resonator
Actions of a Helmholtz Resonator
Other Acoustic Resonators Tube Resonators
Uniform tube closed at one end
Uniform tube closed at one end (2)
Uniform tube closed at one end
Comparing Helmholtz and tube resonators
Slide 122
Slide 123
What is an ldquoAcousticrdquo Filter
bull holds back (attenuates) certain sounds and lets other sounds through - selective
Why might we be interested in filters
bull Human vocal tract acts like a frequency selective acoustic filter
bull Human auditory system behaves as a frequency selective filter
bull helps us understand how speech is produced and perceived
Kinds of frequency selective filters
Low-pass filtersndash Lets low frequencies ldquopass throughrdquo and attenuates high
frequencies
High-pass filtersndash Lets high frequencies ldquopass throughrdquo and attenuates low
frequencies
Band-pass filtersndash Lets a particular frequency range ldquopass throughrdquo and
attenuates other frequencies
Low Pass Filters
Frequencylow high
Gai
n
+
-
High Pass Filters
Frequencylow high
Gai
n
+
-
Band Pass Filter
Frequencylow high
Gai
n
+
-
Frequency Response Curve (FRC)
Frequencylow high
Gai
n
+
-
Center frequency
lower cutofffrequency
upper cutoff frequency
passband
3 dB
Operation of a filter on a signal
NOTE Amplitude spectrum describes a soundFrequency response curve describes a filter
Learning Objectivesbull Define resonance free and forced vibrationbull Describe how the pendulum and spring mass models can
help explain resonancebull Outline how mass and stiffness influences the resonant
frequency of a mass spring systembull Outline how acoustic resonators behave like acoustic filtersbull Calculate resonant frequencies of a uniform tube based on
its physical dimensionsbull Describe how the wavelength of the sound determines the
resonant frequency of tube
Free vibration
bull objects tend to vibrate at a characteristic or resonant frequency (RF)
Forced vibration
bull A vibrating system can force a nearby system into vibration
bull The efficiency with which this is accomplished is related to the similarity in the resonant frequency (RF) of the two systems
Forced vibration
bull If the RF of the two systems are the same the amplitude of forced vibration will be large
bull If the RF of the two systems are quite different the amplitude of forced vibration will be small or nonexistent
Resonance refers to
bull The tendency for an object to vibrate at a particular frequency or frequencies
bull The ability of a vibrating system to force another system into vibration
Back to the mass spring model
bull Vibratory frequency of the mass spring determined byndash Massndash Stiffness of the spring
httpphetcoloradoeduensimulationmass-spring-lab
Acoustic Resonance
bull Ideas from mechanical resonance also applies to acoustic systems
bull Acoustic chambers will transmit sound frequencies with more or less efficiency depending upon the physical characteristics
bull Therefore they act as filters passing through (and even amplifying) some frequencies and attentuating others
Acoustic Resonance
bull And since they act as filters they have most of the same features of a filter even though we might use different names
bull Center frequency is often termed the resonant frequency
bull Frequency response curve often termed the resonance curve
Helmholtz Resonator
Actions of a Helmholtz Resonator
Stephen M Tasko
Other Acoustic Resonators Tube Resonators
bull Uniform tubes Factors that influence resonancendash Lengthndash Cross-sectional area along its lengthndash Whether it is closed at either or both ends
Uniform tube closed at one end
Uniform tube closed at one end
Stephen M Tasko
Uniform tube closed at one end
First resonance or formant
F1 = c4lWhere
c=speed of sound (35000 cmsec)l = length of the tube
males ~ 175 cmfemales ~ 14 cm
Higher resonantformant frequencies are odd multiples of F1
For examplebull F1 = (c4l )1
bull F2 = (c4l )3
bull F3 = (c4l )5
Comparing Helmholtz and tube resonators
Resonator Features
Sharply tuned Broadly tuned
Resonator Features
An example of the resonance characteristics of the human vocal tract
Frequency
Gain
SPPA 4030 Speech Science
Topic 1 The Speech Chain
The Speech Chain (Denes amp Pinson 1993)
What information is embedded in the speech signal
Branches of science employed to understand speech communication
Physical Quantities Review An Independent Learning Activity
Assignment 1
Topic 2 The Source-Filter Theory of Speech Production An Intr
Producing Speech
Source-Filter Theory of Speech Production
Vocal tract is a tube that can vary its shape
Source Filter Theory
Same Source Different Filter
Different Source Same Filters
Different Source Same Filters (Human)
Different Source Same Filters (Human) (2)
Different Source Same Filters (Human) (3)
Different Source Same Filters (Human) (4)
Different Source Same Filters (Non-Human)
Different Source Same Filters (Non-Human) (2)
Different Source Same Filters (Non-Human) If it quacks like a
Source Filter Theory Applied Alaryngeal Speech
Source-Filter Theory Applied Esophageal Insufflation Test
Source-Filter Theory Applied Tracheoesophageal (TE) Speech
Source Filter Theory Applied The Talkbox
Source-Filter Theory Applied The Talkbox
Topic 3 A Brief Review of Physical Acoustics
Spring Mass Model
What is sound
Sound-conducting media
Model of air molecule vibration (Time 1)
Model of air molecule vibration (Time 2)
Model of air molecule vibration (Time 3)
Model of air molecule vibration (Time 4)
Model of air molecule vibration (Time 5)
Model of air molecule vibration
Wave action of molecular motion
Amplitude waveform
Amplitude waveform (2)
Where is pressure in this model
Pressure waveform
Measuring Sound
Measuring Sound Signal Amplitude
Measuring Sound Signal Amplitude (2)
What units do we use to measure signal amplitude
Brief Review The decibel scale
Absolute vs relative measurement
Typical reference values
Howeverhellip
Linear vs logarithmic
Linear vs logarithmic (2)
Logarithmic Scale
Logarithmic Scale (2)
Combining the idea of logarithmic and relativehellip
Intensity vs Pressure
Extending the formula to pressure
Measuring Sound Frequencyperiod
Measuring Sound Frequencyperiod (2)
Phase Uniform Circular Motion
Initiating a sound waves that differ only in phase
Spatial variation in pressure wave
Spatial variation in pressure wave
Spatial variation in pressure wave (2)
Relation between frequency and wavelength
Learning Objectives
Graphic representation of sound
Same sound different graphs
Classification of sounds
Simple periodic sound
Simple periodic sound Graphic appearance
Complex periodic sounds
Complex periodic sounds Graphic appearance
Complex periodic sounds Graphic appearance (2)
Glottal Source
Amplitude vs Phase Spectrum
Amplitude vs Phase Spectrum (2)
(Complex) Aperiodic sounds
Aperiodic sounds Graphic appearance
Aperiodic sounds Graphic appearance (2)
Analysis of complex waves
Learning Objectives (2)
The ldquoenveloperdquo of a sound wave
Waveform envelope
Waveform envelope (2)
Spectrum envelope
Thought Question
Amplitude Spectrum Window Size
ldquoInstantaneousrdquo Amplitude Spectra
(Long Term) Average Amplitude Spectrum
Slide 90
Learning Objectives (3)
The Spectrogram
Building a spectrogram
Building a spectrogram
Building a spectrogram (2)
Two main types of spectrograms
Wide vs Narrow Band Spectrograms
Learning Objectives (4)
What is an ldquoAcousticrdquo Filter
Why might we be interested in filters
Kinds of frequency selective filters
Low Pass Filters
High Pass Filters
Band Pass Filter
Frequency Response Curve (FRC)
Operation of a filter on a signal
Learning Objectives (5)
Free vibration
Forced vibration
Forced vibration (2)
Resonance refers to
Back to the mass spring model
Acoustic Resonance
Acoustic Resonance (2)
Helmholtz Resonator
Actions of a Helmholtz Resonator
Other Acoustic Resonators Tube Resonators
Uniform tube closed at one end
Uniform tube closed at one end (2)
Uniform tube closed at one end
Comparing Helmholtz and tube resonators
Slide 122
Slide 123
Why might we be interested in filters
bull Human vocal tract acts like a frequency selective acoustic filter
bull Human auditory system behaves as a frequency selective filter
bull helps us understand how speech is produced and perceived
Kinds of frequency selective filters
Low-pass filtersndash Lets low frequencies ldquopass throughrdquo and attenuates high
frequencies
High-pass filtersndash Lets high frequencies ldquopass throughrdquo and attenuates low
frequencies
Band-pass filtersndash Lets a particular frequency range ldquopass throughrdquo and
attenuates other frequencies
Low Pass Filters
Frequencylow high
Gai
n
+
-
High Pass Filters
Frequencylow high
Gai
n
+
-
Band Pass Filter
Frequencylow high
Gai
n
+
-
Frequency Response Curve (FRC)
Frequencylow high
Gai
n
+
-
Center frequency
lower cutofffrequency
upper cutoff frequency
passband
3 dB
Operation of a filter on a signal
NOTE Amplitude spectrum describes a soundFrequency response curve describes a filter
Learning Objectivesbull Define resonance free and forced vibrationbull Describe how the pendulum and spring mass models can
help explain resonancebull Outline how mass and stiffness influences the resonant
frequency of a mass spring systembull Outline how acoustic resonators behave like acoustic filtersbull Calculate resonant frequencies of a uniform tube based on
its physical dimensionsbull Describe how the wavelength of the sound determines the
resonant frequency of tube
Free vibration
bull objects tend to vibrate at a characteristic or resonant frequency (RF)
Forced vibration
bull A vibrating system can force a nearby system into vibration
bull The efficiency with which this is accomplished is related to the similarity in the resonant frequency (RF) of the two systems
Forced vibration
bull If the RF of the two systems are the same the amplitude of forced vibration will be large
bull If the RF of the two systems are quite different the amplitude of forced vibration will be small or nonexistent
Resonance refers to
bull The tendency for an object to vibrate at a particular frequency or frequencies
bull The ability of a vibrating system to force another system into vibration
Back to the mass spring model
bull Vibratory frequency of the mass spring determined byndash Massndash Stiffness of the spring
httpphetcoloradoeduensimulationmass-spring-lab
Acoustic Resonance
bull Ideas from mechanical resonance also applies to acoustic systems
bull Acoustic chambers will transmit sound frequencies with more or less efficiency depending upon the physical characteristics
bull Therefore they act as filters passing through (and even amplifying) some frequencies and attentuating others
Acoustic Resonance
bull And since they act as filters they have most of the same features of a filter even though we might use different names
bull Center frequency is often termed the resonant frequency
bull Frequency response curve often termed the resonance curve
Helmholtz Resonator
Actions of a Helmholtz Resonator
Stephen M Tasko
Other Acoustic Resonators Tube Resonators
bull Uniform tubes Factors that influence resonancendash Lengthndash Cross-sectional area along its lengthndash Whether it is closed at either or both ends
Uniform tube closed at one end
Uniform tube closed at one end
Stephen M Tasko
Uniform tube closed at one end
First resonance or formant
F1 = c4lWhere
c=speed of sound (35000 cmsec)l = length of the tube
males ~ 175 cmfemales ~ 14 cm
Higher resonantformant frequencies are odd multiples of F1
For examplebull F1 = (c4l )1
bull F2 = (c4l )3
bull F3 = (c4l )5
Comparing Helmholtz and tube resonators
Resonator Features
Sharply tuned Broadly tuned
Resonator Features
An example of the resonance characteristics of the human vocal tract
Frequency
Gain
SPPA 4030 Speech Science
Topic 1 The Speech Chain
The Speech Chain (Denes amp Pinson 1993)
What information is embedded in the speech signal
Branches of science employed to understand speech communication
Physical Quantities Review An Independent Learning Activity
Assignment 1
Topic 2 The Source-Filter Theory of Speech Production An Intr
Producing Speech
Source-Filter Theory of Speech Production
Vocal tract is a tube that can vary its shape
Source Filter Theory
Same Source Different Filter
Different Source Same Filters
Different Source Same Filters (Human)
Different Source Same Filters (Human) (2)
Different Source Same Filters (Human) (3)
Different Source Same Filters (Human) (4)
Different Source Same Filters (Non-Human)
Different Source Same Filters (Non-Human) (2)
Different Source Same Filters (Non-Human) If it quacks like a
Source Filter Theory Applied Alaryngeal Speech
Source-Filter Theory Applied Esophageal Insufflation Test
Source-Filter Theory Applied Tracheoesophageal (TE) Speech
Source Filter Theory Applied The Talkbox
Source-Filter Theory Applied The Talkbox
Topic 3 A Brief Review of Physical Acoustics
Spring Mass Model
What is sound
Sound-conducting media
Model of air molecule vibration (Time 1)
Model of air molecule vibration (Time 2)
Model of air molecule vibration (Time 3)
Model of air molecule vibration (Time 4)
Model of air molecule vibration (Time 5)
Model of air molecule vibration
Wave action of molecular motion
Amplitude waveform
Amplitude waveform (2)
Where is pressure in this model
Pressure waveform
Measuring Sound
Measuring Sound Signal Amplitude
Measuring Sound Signal Amplitude (2)
What units do we use to measure signal amplitude
Brief Review The decibel scale
Absolute vs relative measurement
Typical reference values
Howeverhellip
Linear vs logarithmic
Linear vs logarithmic (2)
Logarithmic Scale
Logarithmic Scale (2)
Combining the idea of logarithmic and relativehellip
Intensity vs Pressure
Extending the formula to pressure
Measuring Sound Frequencyperiod
Measuring Sound Frequencyperiod (2)
Phase Uniform Circular Motion
Initiating a sound waves that differ only in phase
Spatial variation in pressure wave
Spatial variation in pressure wave
Spatial variation in pressure wave (2)
Relation between frequency and wavelength
Learning Objectives
Graphic representation of sound
Same sound different graphs
Classification of sounds
Simple periodic sound
Simple periodic sound Graphic appearance
Complex periodic sounds
Complex periodic sounds Graphic appearance
Complex periodic sounds Graphic appearance (2)
Glottal Source
Amplitude vs Phase Spectrum
Amplitude vs Phase Spectrum (2)
(Complex) Aperiodic sounds
Aperiodic sounds Graphic appearance
Aperiodic sounds Graphic appearance (2)
Analysis of complex waves
Learning Objectives (2)
The ldquoenveloperdquo of a sound wave
Waveform envelope
Waveform envelope (2)
Spectrum envelope
Thought Question
Amplitude Spectrum Window Size
ldquoInstantaneousrdquo Amplitude Spectra
(Long Term) Average Amplitude Spectrum
Slide 90
Learning Objectives (3)
The Spectrogram
Building a spectrogram
Building a spectrogram
Building a spectrogram (2)
Two main types of spectrograms
Wide vs Narrow Band Spectrograms
Learning Objectives (4)
What is an ldquoAcousticrdquo Filter
Why might we be interested in filters
Kinds of frequency selective filters
Low Pass Filters
High Pass Filters
Band Pass Filter
Frequency Response Curve (FRC)
Operation of a filter on a signal
Learning Objectives (5)
Free vibration
Forced vibration
Forced vibration (2)
Resonance refers to
Back to the mass spring model
Acoustic Resonance
Acoustic Resonance (2)
Helmholtz Resonator
Actions of a Helmholtz Resonator
Other Acoustic Resonators Tube Resonators
Uniform tube closed at one end
Uniform tube closed at one end (2)
Uniform tube closed at one end
Comparing Helmholtz and tube resonators
Slide 122
Slide 123
Kinds of frequency selective filters
Low-pass filtersndash Lets low frequencies ldquopass throughrdquo and attenuates high
frequencies
High-pass filtersndash Lets high frequencies ldquopass throughrdquo and attenuates low
frequencies
Band-pass filtersndash Lets a particular frequency range ldquopass throughrdquo and
attenuates other frequencies
Low Pass Filters
Frequencylow high
Gai
n
+
-
High Pass Filters
Frequencylow high
Gai
n
+
-
Band Pass Filter
Frequencylow high
Gai
n
+
-
Frequency Response Curve (FRC)
Frequencylow high
Gai
n
+
-
Center frequency
lower cutofffrequency
upper cutoff frequency
passband
3 dB
Operation of a filter on a signal
NOTE Amplitude spectrum describes a soundFrequency response curve describes a filter
Learning Objectivesbull Define resonance free and forced vibrationbull Describe how the pendulum and spring mass models can
help explain resonancebull Outline how mass and stiffness influences the resonant
frequency of a mass spring systembull Outline how acoustic resonators behave like acoustic filtersbull Calculate resonant frequencies of a uniform tube based on
its physical dimensionsbull Describe how the wavelength of the sound determines the
resonant frequency of tube
Free vibration
bull objects tend to vibrate at a characteristic or resonant frequency (RF)
Forced vibration
bull A vibrating system can force a nearby system into vibration
bull The efficiency with which this is accomplished is related to the similarity in the resonant frequency (RF) of the two systems
Forced vibration
bull If the RF of the two systems are the same the amplitude of forced vibration will be large
bull If the RF of the two systems are quite different the amplitude of forced vibration will be small or nonexistent
Resonance refers to
bull The tendency for an object to vibrate at a particular frequency or frequencies
bull The ability of a vibrating system to force another system into vibration
Back to the mass spring model
bull Vibratory frequency of the mass spring determined byndash Massndash Stiffness of the spring
httpphetcoloradoeduensimulationmass-spring-lab
Acoustic Resonance
bull Ideas from mechanical resonance also applies to acoustic systems
bull Acoustic chambers will transmit sound frequencies with more or less efficiency depending upon the physical characteristics
bull Therefore they act as filters passing through (and even amplifying) some frequencies and attentuating others
Acoustic Resonance
bull And since they act as filters they have most of the same features of a filter even though we might use different names
bull Center frequency is often termed the resonant frequency
bull Frequency response curve often termed the resonance curve
Helmholtz Resonator
Actions of a Helmholtz Resonator
Stephen M Tasko
Other Acoustic Resonators Tube Resonators
bull Uniform tubes Factors that influence resonancendash Lengthndash Cross-sectional area along its lengthndash Whether it is closed at either or both ends
Uniform tube closed at one end
Uniform tube closed at one end
Stephen M Tasko
Uniform tube closed at one end
First resonance or formant
F1 = c4lWhere
c=speed of sound (35000 cmsec)l = length of the tube
males ~ 175 cmfemales ~ 14 cm
Higher resonantformant frequencies are odd multiples of F1
For examplebull F1 = (c4l )1
bull F2 = (c4l )3
bull F3 = (c4l )5
Comparing Helmholtz and tube resonators
Resonator Features
Sharply tuned Broadly tuned
Resonator Features
An example of the resonance characteristics of the human vocal tract
Frequency
Gain
SPPA 4030 Speech Science
Topic 1 The Speech Chain
The Speech Chain (Denes amp Pinson 1993)
What information is embedded in the speech signal
Branches of science employed to understand speech communication
Physical Quantities Review An Independent Learning Activity
Assignment 1
Topic 2 The Source-Filter Theory of Speech Production An Intr
Producing Speech
Source-Filter Theory of Speech Production
Vocal tract is a tube that can vary its shape
Source Filter Theory
Same Source Different Filter
Different Source Same Filters
Different Source Same Filters (Human)
Different Source Same Filters (Human) (2)
Different Source Same Filters (Human) (3)
Different Source Same Filters (Human) (4)
Different Source Same Filters (Non-Human)
Different Source Same Filters (Non-Human) (2)
Different Source Same Filters (Non-Human) If it quacks like a
Source Filter Theory Applied Alaryngeal Speech
Source-Filter Theory Applied Esophageal Insufflation Test
Source-Filter Theory Applied Tracheoesophageal (TE) Speech
Source Filter Theory Applied The Talkbox
Source-Filter Theory Applied The Talkbox
Topic 3 A Brief Review of Physical Acoustics
Spring Mass Model
What is sound
Sound-conducting media
Model of air molecule vibration (Time 1)
Model of air molecule vibration (Time 2)
Model of air molecule vibration (Time 3)
Model of air molecule vibration (Time 4)
Model of air molecule vibration (Time 5)
Model of air molecule vibration
Wave action of molecular motion
Amplitude waveform
Amplitude waveform (2)
Where is pressure in this model
Pressure waveform
Measuring Sound
Measuring Sound Signal Amplitude
Measuring Sound Signal Amplitude (2)
What units do we use to measure signal amplitude
Brief Review The decibel scale
Absolute vs relative measurement
Typical reference values
Howeverhellip
Linear vs logarithmic
Linear vs logarithmic (2)
Logarithmic Scale
Logarithmic Scale (2)
Combining the idea of logarithmic and relativehellip
Intensity vs Pressure
Extending the formula to pressure
Measuring Sound Frequencyperiod
Measuring Sound Frequencyperiod (2)
Phase Uniform Circular Motion
Initiating a sound waves that differ only in phase
Spatial variation in pressure wave
Spatial variation in pressure wave
Spatial variation in pressure wave (2)
Relation between frequency and wavelength
Learning Objectives
Graphic representation of sound
Same sound different graphs
Classification of sounds
Simple periodic sound
Simple periodic sound Graphic appearance
Complex periodic sounds
Complex periodic sounds Graphic appearance
Complex periodic sounds Graphic appearance (2)
Glottal Source
Amplitude vs Phase Spectrum
Amplitude vs Phase Spectrum (2)
(Complex) Aperiodic sounds
Aperiodic sounds Graphic appearance
Aperiodic sounds Graphic appearance (2)
Analysis of complex waves
Learning Objectives (2)
The ldquoenveloperdquo of a sound wave
Waveform envelope
Waveform envelope (2)
Spectrum envelope
Thought Question
Amplitude Spectrum Window Size
ldquoInstantaneousrdquo Amplitude Spectra
(Long Term) Average Amplitude Spectrum
Slide 90
Learning Objectives (3)
The Spectrogram
Building a spectrogram
Building a spectrogram
Building a spectrogram (2)
Two main types of spectrograms
Wide vs Narrow Band Spectrograms
Learning Objectives (4)
What is an ldquoAcousticrdquo Filter
Why might we be interested in filters
Kinds of frequency selective filters
Low Pass Filters
High Pass Filters
Band Pass Filter
Frequency Response Curve (FRC)
Operation of a filter on a signal
Learning Objectives (5)
Free vibration
Forced vibration
Forced vibration (2)
Resonance refers to
Back to the mass spring model
Acoustic Resonance
Acoustic Resonance (2)
Helmholtz Resonator
Actions of a Helmholtz Resonator
Other Acoustic Resonators Tube Resonators
Uniform tube closed at one end
Uniform tube closed at one end (2)
Uniform tube closed at one end
Comparing Helmholtz and tube resonators
Slide 122
Slide 123
Low Pass Filters
Frequencylow high
Gai
n
+
-
High Pass Filters
Frequencylow high
Gai
n
+
-
Band Pass Filter
Frequencylow high
Gai
n
+
-
Frequency Response Curve (FRC)
Frequencylow high
Gai
n
+
-
Center frequency
lower cutofffrequency
upper cutoff frequency
passband
3 dB
Operation of a filter on a signal
NOTE Amplitude spectrum describes a soundFrequency response curve describes a filter
Learning Objectivesbull Define resonance free and forced vibrationbull Describe how the pendulum and spring mass models can
help explain resonancebull Outline how mass and stiffness influences the resonant
frequency of a mass spring systembull Outline how acoustic resonators behave like acoustic filtersbull Calculate resonant frequencies of a uniform tube based on
its physical dimensionsbull Describe how the wavelength of the sound determines the
resonant frequency of tube
Free vibration
bull objects tend to vibrate at a characteristic or resonant frequency (RF)
Forced vibration
bull A vibrating system can force a nearby system into vibration
bull The efficiency with which this is accomplished is related to the similarity in the resonant frequency (RF) of the two systems
Forced vibration
bull If the RF of the two systems are the same the amplitude of forced vibration will be large
bull If the RF of the two systems are quite different the amplitude of forced vibration will be small or nonexistent
Resonance refers to
bull The tendency for an object to vibrate at a particular frequency or frequencies
bull The ability of a vibrating system to force another system into vibration
Back to the mass spring model
bull Vibratory frequency of the mass spring determined byndash Massndash Stiffness of the spring
httpphetcoloradoeduensimulationmass-spring-lab
Acoustic Resonance
bull Ideas from mechanical resonance also applies to acoustic systems
bull Acoustic chambers will transmit sound frequencies with more or less efficiency depending upon the physical characteristics
bull Therefore they act as filters passing through (and even amplifying) some frequencies and attentuating others
Acoustic Resonance
bull And since they act as filters they have most of the same features of a filter even though we might use different names
bull Center frequency is often termed the resonant frequency
bull Frequency response curve often termed the resonance curve
Helmholtz Resonator
Actions of a Helmholtz Resonator
Stephen M Tasko
Other Acoustic Resonators Tube Resonators
bull Uniform tubes Factors that influence resonancendash Lengthndash Cross-sectional area along its lengthndash Whether it is closed at either or both ends
Uniform tube closed at one end
Uniform tube closed at one end
Stephen M Tasko
Uniform tube closed at one end
First resonance or formant
F1 = c4lWhere
c=speed of sound (35000 cmsec)l = length of the tube
males ~ 175 cmfemales ~ 14 cm
Higher resonantformant frequencies are odd multiples of F1
For examplebull F1 = (c4l )1
bull F2 = (c4l )3
bull F3 = (c4l )5
Comparing Helmholtz and tube resonators
Resonator Features
Sharply tuned Broadly tuned
Resonator Features
An example of the resonance characteristics of the human vocal tract
Frequency
Gain
SPPA 4030 Speech Science
Topic 1 The Speech Chain
The Speech Chain (Denes amp Pinson 1993)
What information is embedded in the speech signal
Branches of science employed to understand speech communication
Physical Quantities Review An Independent Learning Activity
Assignment 1
Topic 2 The Source-Filter Theory of Speech Production An Intr
Producing Speech
Source-Filter Theory of Speech Production
Vocal tract is a tube that can vary its shape
Source Filter Theory
Same Source Different Filter
Different Source Same Filters
Different Source Same Filters (Human)
Different Source Same Filters (Human) (2)
Different Source Same Filters (Human) (3)
Different Source Same Filters (Human) (4)
Different Source Same Filters (Non-Human)
Different Source Same Filters (Non-Human) (2)
Different Source Same Filters (Non-Human) If it quacks like a
Source Filter Theory Applied Alaryngeal Speech
Source-Filter Theory Applied Esophageal Insufflation Test
Source-Filter Theory Applied Tracheoesophageal (TE) Speech
Source Filter Theory Applied The Talkbox
Source-Filter Theory Applied The Talkbox
Topic 3 A Brief Review of Physical Acoustics
Spring Mass Model
What is sound
Sound-conducting media
Model of air molecule vibration (Time 1)
Model of air molecule vibration (Time 2)
Model of air molecule vibration (Time 3)
Model of air molecule vibration (Time 4)
Model of air molecule vibration (Time 5)
Model of air molecule vibration
Wave action of molecular motion
Amplitude waveform
Amplitude waveform (2)
Where is pressure in this model
Pressure waveform
Measuring Sound
Measuring Sound Signal Amplitude
Measuring Sound Signal Amplitude (2)
What units do we use to measure signal amplitude
Brief Review The decibel scale
Absolute vs relative measurement
Typical reference values
Howeverhellip
Linear vs logarithmic
Linear vs logarithmic (2)
Logarithmic Scale
Logarithmic Scale (2)
Combining the idea of logarithmic and relativehellip
Intensity vs Pressure
Extending the formula to pressure
Measuring Sound Frequencyperiod
Measuring Sound Frequencyperiod (2)
Phase Uniform Circular Motion
Initiating a sound waves that differ only in phase
Spatial variation in pressure wave
Spatial variation in pressure wave
Spatial variation in pressure wave (2)
Relation between frequency and wavelength
Learning Objectives
Graphic representation of sound
Same sound different graphs
Classification of sounds
Simple periodic sound
Simple periodic sound Graphic appearance
Complex periodic sounds
Complex periodic sounds Graphic appearance
Complex periodic sounds Graphic appearance (2)
Glottal Source
Amplitude vs Phase Spectrum
Amplitude vs Phase Spectrum (2)
(Complex) Aperiodic sounds
Aperiodic sounds Graphic appearance
Aperiodic sounds Graphic appearance (2)
Analysis of complex waves
Learning Objectives (2)
The ldquoenveloperdquo of a sound wave
Waveform envelope
Waveform envelope (2)
Spectrum envelope
Thought Question
Amplitude Spectrum Window Size
ldquoInstantaneousrdquo Amplitude Spectra
(Long Term) Average Amplitude Spectrum
Slide 90
Learning Objectives (3)
The Spectrogram
Building a spectrogram
Building a spectrogram
Building a spectrogram (2)
Two main types of spectrograms
Wide vs Narrow Band Spectrograms
Learning Objectives (4)
What is an ldquoAcousticrdquo Filter
Why might we be interested in filters
Kinds of frequency selective filters
Low Pass Filters
High Pass Filters
Band Pass Filter
Frequency Response Curve (FRC)
Operation of a filter on a signal
Learning Objectives (5)
Free vibration
Forced vibration
Forced vibration (2)
Resonance refers to
Back to the mass spring model
Acoustic Resonance
Acoustic Resonance (2)
Helmholtz Resonator
Actions of a Helmholtz Resonator
Other Acoustic Resonators Tube Resonators
Uniform tube closed at one end
Uniform tube closed at one end (2)
Uniform tube closed at one end
Comparing Helmholtz and tube resonators
Slide 122
Slide 123
High Pass Filters
Frequencylow high
Gai
n
+
-
Band Pass Filter
Frequencylow high
Gai
n
+
-
Frequency Response Curve (FRC)
Frequencylow high
Gai
n
+
-
Center frequency
lower cutofffrequency
upper cutoff frequency
passband
3 dB
Operation of a filter on a signal
NOTE Amplitude spectrum describes a soundFrequency response curve describes a filter
Learning Objectivesbull Define resonance free and forced vibrationbull Describe how the pendulum and spring mass models can
help explain resonancebull Outline how mass and stiffness influences the resonant
frequency of a mass spring systembull Outline how acoustic resonators behave like acoustic filtersbull Calculate resonant frequencies of a uniform tube based on
its physical dimensionsbull Describe how the wavelength of the sound determines the
resonant frequency of tube
Free vibration
bull objects tend to vibrate at a characteristic or resonant frequency (RF)
Forced vibration
bull A vibrating system can force a nearby system into vibration
bull The efficiency with which this is accomplished is related to the similarity in the resonant frequency (RF) of the two systems
Forced vibration
bull If the RF of the two systems are the same the amplitude of forced vibration will be large
bull If the RF of the two systems are quite different the amplitude of forced vibration will be small or nonexistent
Resonance refers to
bull The tendency for an object to vibrate at a particular frequency or frequencies
bull The ability of a vibrating system to force another system into vibration
Back to the mass spring model
bull Vibratory frequency of the mass spring determined byndash Massndash Stiffness of the spring
httpphetcoloradoeduensimulationmass-spring-lab
Acoustic Resonance
bull Ideas from mechanical resonance also applies to acoustic systems
bull Acoustic chambers will transmit sound frequencies with more or less efficiency depending upon the physical characteristics
bull Therefore they act as filters passing through (and even amplifying) some frequencies and attentuating others
Acoustic Resonance
bull And since they act as filters they have most of the same features of a filter even though we might use different names
bull Center frequency is often termed the resonant frequency
bull Frequency response curve often termed the resonance curve
Helmholtz Resonator
Actions of a Helmholtz Resonator
Stephen M Tasko
Other Acoustic Resonators Tube Resonators
bull Uniform tubes Factors that influence resonancendash Lengthndash Cross-sectional area along its lengthndash Whether it is closed at either or both ends
Uniform tube closed at one end
Uniform tube closed at one end
Stephen M Tasko
Uniform tube closed at one end
First resonance or formant
F1 = c4lWhere
c=speed of sound (35000 cmsec)l = length of the tube
males ~ 175 cmfemales ~ 14 cm
Higher resonantformant frequencies are odd multiples of F1
For examplebull F1 = (c4l )1
bull F2 = (c4l )3
bull F3 = (c4l )5
Comparing Helmholtz and tube resonators
Resonator Features
Sharply tuned Broadly tuned
Resonator Features
An example of the resonance characteristics of the human vocal tract
Frequency
Gain
SPPA 4030 Speech Science
Topic 1 The Speech Chain
The Speech Chain (Denes amp Pinson 1993)
What information is embedded in the speech signal
Branches of science employed to understand speech communication
Physical Quantities Review An Independent Learning Activity
Assignment 1
Topic 2 The Source-Filter Theory of Speech Production An Intr
Producing Speech
Source-Filter Theory of Speech Production
Vocal tract is a tube that can vary its shape
Source Filter Theory
Same Source Different Filter
Different Source Same Filters
Different Source Same Filters (Human)
Different Source Same Filters (Human) (2)
Different Source Same Filters (Human) (3)
Different Source Same Filters (Human) (4)
Different Source Same Filters (Non-Human)
Different Source Same Filters (Non-Human) (2)
Different Source Same Filters (Non-Human) If it quacks like a
Source Filter Theory Applied Alaryngeal Speech
Source-Filter Theory Applied Esophageal Insufflation Test
Source-Filter Theory Applied Tracheoesophageal (TE) Speech
Source Filter Theory Applied The Talkbox
Source-Filter Theory Applied The Talkbox
Topic 3 A Brief Review of Physical Acoustics
Spring Mass Model
What is sound
Sound-conducting media
Model of air molecule vibration (Time 1)
Model of air molecule vibration (Time 2)
Model of air molecule vibration (Time 3)
Model of air molecule vibration (Time 4)
Model of air molecule vibration (Time 5)
Model of air molecule vibration
Wave action of molecular motion
Amplitude waveform
Amplitude waveform (2)
Where is pressure in this model
Pressure waveform
Measuring Sound
Measuring Sound Signal Amplitude
Measuring Sound Signal Amplitude (2)
What units do we use to measure signal amplitude
Brief Review The decibel scale
Absolute vs relative measurement
Typical reference values
Howeverhellip
Linear vs logarithmic
Linear vs logarithmic (2)
Logarithmic Scale
Logarithmic Scale (2)
Combining the idea of logarithmic and relativehellip
Intensity vs Pressure
Extending the formula to pressure
Measuring Sound Frequencyperiod
Measuring Sound Frequencyperiod (2)
Phase Uniform Circular Motion
Initiating a sound waves that differ only in phase
Spatial variation in pressure wave
Spatial variation in pressure wave
Spatial variation in pressure wave (2)
Relation between frequency and wavelength
Learning Objectives
Graphic representation of sound
Same sound different graphs
Classification of sounds
Simple periodic sound
Simple periodic sound Graphic appearance
Complex periodic sounds
Complex periodic sounds Graphic appearance
Complex periodic sounds Graphic appearance (2)
Glottal Source
Amplitude vs Phase Spectrum
Amplitude vs Phase Spectrum (2)
(Complex) Aperiodic sounds
Aperiodic sounds Graphic appearance
Aperiodic sounds Graphic appearance (2)
Analysis of complex waves
Learning Objectives (2)
The ldquoenveloperdquo of a sound wave
Waveform envelope
Waveform envelope (2)
Spectrum envelope
Thought Question
Amplitude Spectrum Window Size
ldquoInstantaneousrdquo Amplitude Spectra
(Long Term) Average Amplitude Spectrum
Slide 90
Learning Objectives (3)
The Spectrogram
Building a spectrogram
Building a spectrogram
Building a spectrogram (2)
Two main types of spectrograms
Wide vs Narrow Band Spectrograms
Learning Objectives (4)
What is an ldquoAcousticrdquo Filter
Why might we be interested in filters
Kinds of frequency selective filters
Low Pass Filters
High Pass Filters
Band Pass Filter
Frequency Response Curve (FRC)
Operation of a filter on a signal
Learning Objectives (5)
Free vibration
Forced vibration
Forced vibration (2)
Resonance refers to
Back to the mass spring model
Acoustic Resonance
Acoustic Resonance (2)
Helmholtz Resonator
Actions of a Helmholtz Resonator
Other Acoustic Resonators Tube Resonators
Uniform tube closed at one end
Uniform tube closed at one end (2)
Uniform tube closed at one end
Comparing Helmholtz and tube resonators
Slide 122
Slide 123
Band Pass Filter
Frequencylow high
Gai
n
+
-
Frequency Response Curve (FRC)
Frequencylow high
Gai
n
+
-
Center frequency
lower cutofffrequency
upper cutoff frequency
passband
3 dB
Operation of a filter on a signal
NOTE Amplitude spectrum describes a soundFrequency response curve describes a filter
Learning Objectivesbull Define resonance free and forced vibrationbull Describe how the pendulum and spring mass models can
help explain resonancebull Outline how mass and stiffness influences the resonant
frequency of a mass spring systembull Outline how acoustic resonators behave like acoustic filtersbull Calculate resonant frequencies of a uniform tube based on
its physical dimensionsbull Describe how the wavelength of the sound determines the
resonant frequency of tube
Free vibration
bull objects tend to vibrate at a characteristic or resonant frequency (RF)
Forced vibration
bull A vibrating system can force a nearby system into vibration
bull The efficiency with which this is accomplished is related to the similarity in the resonant frequency (RF) of the two systems
Forced vibration
bull If the RF of the two systems are the same the amplitude of forced vibration will be large
bull If the RF of the two systems are quite different the amplitude of forced vibration will be small or nonexistent
Resonance refers to
bull The tendency for an object to vibrate at a particular frequency or frequencies
bull The ability of a vibrating system to force another system into vibration
Back to the mass spring model
bull Vibratory frequency of the mass spring determined byndash Massndash Stiffness of the spring
httpphetcoloradoeduensimulationmass-spring-lab
Acoustic Resonance
bull Ideas from mechanical resonance also applies to acoustic systems
bull Acoustic chambers will transmit sound frequencies with more or less efficiency depending upon the physical characteristics
bull Therefore they act as filters passing through (and even amplifying) some frequencies and attentuating others
Acoustic Resonance
bull And since they act as filters they have most of the same features of a filter even though we might use different names
bull Center frequency is often termed the resonant frequency
bull Frequency response curve often termed the resonance curve
Helmholtz Resonator
Actions of a Helmholtz Resonator
Stephen M Tasko
Other Acoustic Resonators Tube Resonators
bull Uniform tubes Factors that influence resonancendash Lengthndash Cross-sectional area along its lengthndash Whether it is closed at either or both ends
Uniform tube closed at one end
Uniform tube closed at one end
Stephen M Tasko
Uniform tube closed at one end
First resonance or formant
F1 = c4lWhere
c=speed of sound (35000 cmsec)l = length of the tube
males ~ 175 cmfemales ~ 14 cm
Higher resonantformant frequencies are odd multiples of F1
For examplebull F1 = (c4l )1
bull F2 = (c4l )3
bull F3 = (c4l )5
Comparing Helmholtz and tube resonators
Resonator Features
Sharply tuned Broadly tuned
Resonator Features
An example of the resonance characteristics of the human vocal tract
Frequency
Gain
SPPA 4030 Speech Science
Topic 1 The Speech Chain
The Speech Chain (Denes amp Pinson 1993)
What information is embedded in the speech signal
Branches of science employed to understand speech communication
Physical Quantities Review An Independent Learning Activity
Assignment 1
Topic 2 The Source-Filter Theory of Speech Production An Intr
Producing Speech
Source-Filter Theory of Speech Production
Vocal tract is a tube that can vary its shape
Source Filter Theory
Same Source Different Filter
Different Source Same Filters
Different Source Same Filters (Human)
Different Source Same Filters (Human) (2)
Different Source Same Filters (Human) (3)
Different Source Same Filters (Human) (4)
Different Source Same Filters (Non-Human)
Different Source Same Filters (Non-Human) (2)
Different Source Same Filters (Non-Human) If it quacks like a
Source Filter Theory Applied Alaryngeal Speech
Source-Filter Theory Applied Esophageal Insufflation Test
Source-Filter Theory Applied Tracheoesophageal (TE) Speech
Source Filter Theory Applied The Talkbox
Source-Filter Theory Applied The Talkbox
Topic 3 A Brief Review of Physical Acoustics
Spring Mass Model
What is sound
Sound-conducting media
Model of air molecule vibration (Time 1)
Model of air molecule vibration (Time 2)
Model of air molecule vibration (Time 3)
Model of air molecule vibration (Time 4)
Model of air molecule vibration (Time 5)
Model of air molecule vibration
Wave action of molecular motion
Amplitude waveform
Amplitude waveform (2)
Where is pressure in this model
Pressure waveform
Measuring Sound
Measuring Sound Signal Amplitude
Measuring Sound Signal Amplitude (2)
What units do we use to measure signal amplitude
Brief Review The decibel scale
Absolute vs relative measurement
Typical reference values
Howeverhellip
Linear vs logarithmic
Linear vs logarithmic (2)
Logarithmic Scale
Logarithmic Scale (2)
Combining the idea of logarithmic and relativehellip
Intensity vs Pressure
Extending the formula to pressure
Measuring Sound Frequencyperiod
Measuring Sound Frequencyperiod (2)
Phase Uniform Circular Motion
Initiating a sound waves that differ only in phase
Spatial variation in pressure wave
Spatial variation in pressure wave
Spatial variation in pressure wave (2)
Relation between frequency and wavelength
Learning Objectives
Graphic representation of sound
Same sound different graphs
Classification of sounds
Simple periodic sound
Simple periodic sound Graphic appearance
Complex periodic sounds
Complex periodic sounds Graphic appearance
Complex periodic sounds Graphic appearance (2)
Glottal Source
Amplitude vs Phase Spectrum
Amplitude vs Phase Spectrum (2)
(Complex) Aperiodic sounds
Aperiodic sounds Graphic appearance
Aperiodic sounds Graphic appearance (2)
Analysis of complex waves
Learning Objectives (2)
The ldquoenveloperdquo of a sound wave
Waveform envelope
Waveform envelope (2)
Spectrum envelope
Thought Question
Amplitude Spectrum Window Size
ldquoInstantaneousrdquo Amplitude Spectra
(Long Term) Average Amplitude Spectrum
Slide 90
Learning Objectives (3)
The Spectrogram
Building a spectrogram
Building a spectrogram
Building a spectrogram (2)
Two main types of spectrograms
Wide vs Narrow Band Spectrograms
Learning Objectives (4)
What is an ldquoAcousticrdquo Filter
Why might we be interested in filters
Kinds of frequency selective filters
Low Pass Filters
High Pass Filters
Band Pass Filter
Frequency Response Curve (FRC)
Operation of a filter on a signal
Learning Objectives (5)
Free vibration
Forced vibration
Forced vibration (2)
Resonance refers to
Back to the mass spring model
Acoustic Resonance
Acoustic Resonance (2)
Helmholtz Resonator
Actions of a Helmholtz Resonator
Other Acoustic Resonators Tube Resonators
Uniform tube closed at one end
Uniform tube closed at one end (2)
Uniform tube closed at one end
Comparing Helmholtz and tube resonators
Slide 122
Slide 123
Frequency Response Curve (FRC)
Frequencylow high
Gai
n
+
-
Center frequency
lower cutofffrequency
upper cutoff frequency
passband
3 dB
Operation of a filter on a signal
NOTE Amplitude spectrum describes a soundFrequency response curve describes a filter
Learning Objectivesbull Define resonance free and forced vibrationbull Describe how the pendulum and spring mass models can
help explain resonancebull Outline how mass and stiffness influences the resonant
frequency of a mass spring systembull Outline how acoustic resonators behave like acoustic filtersbull Calculate resonant frequencies of a uniform tube based on
its physical dimensionsbull Describe how the wavelength of the sound determines the
resonant frequency of tube
Free vibration
bull objects tend to vibrate at a characteristic or resonant frequency (RF)
Forced vibration
bull A vibrating system can force a nearby system into vibration
bull The efficiency with which this is accomplished is related to the similarity in the resonant frequency (RF) of the two systems
Forced vibration
bull If the RF of the two systems are the same the amplitude of forced vibration will be large
bull If the RF of the two systems are quite different the amplitude of forced vibration will be small or nonexistent
Resonance refers to
bull The tendency for an object to vibrate at a particular frequency or frequencies
bull The ability of a vibrating system to force another system into vibration
Back to the mass spring model
bull Vibratory frequency of the mass spring determined byndash Massndash Stiffness of the spring
httpphetcoloradoeduensimulationmass-spring-lab
Acoustic Resonance
bull Ideas from mechanical resonance also applies to acoustic systems
bull Acoustic chambers will transmit sound frequencies with more or less efficiency depending upon the physical characteristics
bull Therefore they act as filters passing through (and even amplifying) some frequencies and attentuating others
Acoustic Resonance
bull And since they act as filters they have most of the same features of a filter even though we might use different names
bull Center frequency is often termed the resonant frequency
bull Frequency response curve often termed the resonance curve
Helmholtz Resonator
Actions of a Helmholtz Resonator
Stephen M Tasko
Other Acoustic Resonators Tube Resonators
bull Uniform tubes Factors that influence resonancendash Lengthndash Cross-sectional area along its lengthndash Whether it is closed at either or both ends
Uniform tube closed at one end
Uniform tube closed at one end
Stephen M Tasko
Uniform tube closed at one end
First resonance or formant
F1 = c4lWhere
c=speed of sound (35000 cmsec)l = length of the tube
males ~ 175 cmfemales ~ 14 cm
Higher resonantformant frequencies are odd multiples of F1
For examplebull F1 = (c4l )1
bull F2 = (c4l )3
bull F3 = (c4l )5
Comparing Helmholtz and tube resonators
Resonator Features
Sharply tuned Broadly tuned
Resonator Features
An example of the resonance characteristics of the human vocal tract
Frequency
Gain
SPPA 4030 Speech Science
Topic 1 The Speech Chain
The Speech Chain (Denes amp Pinson 1993)
What information is embedded in the speech signal
Branches of science employed to understand speech communication
Physical Quantities Review An Independent Learning Activity
Assignment 1
Topic 2 The Source-Filter Theory of Speech Production An Intr
Producing Speech
Source-Filter Theory of Speech Production
Vocal tract is a tube that can vary its shape
Source Filter Theory
Same Source Different Filter
Different Source Same Filters
Different Source Same Filters (Human)
Different Source Same Filters (Human) (2)
Different Source Same Filters (Human) (3)
Different Source Same Filters (Human) (4)
Different Source Same Filters (Non-Human)
Different Source Same Filters (Non-Human) (2)
Different Source Same Filters (Non-Human) If it quacks like a
Source Filter Theory Applied Alaryngeal Speech
Source-Filter Theory Applied Esophageal Insufflation Test
Source-Filter Theory Applied Tracheoesophageal (TE) Speech
Source Filter Theory Applied The Talkbox
Source-Filter Theory Applied The Talkbox
Topic 3 A Brief Review of Physical Acoustics
Spring Mass Model
What is sound
Sound-conducting media
Model of air molecule vibration (Time 1)
Model of air molecule vibration (Time 2)
Model of air molecule vibration (Time 3)
Model of air molecule vibration (Time 4)
Model of air molecule vibration (Time 5)
Model of air molecule vibration
Wave action of molecular motion
Amplitude waveform
Amplitude waveform (2)
Where is pressure in this model
Pressure waveform
Measuring Sound
Measuring Sound Signal Amplitude
Measuring Sound Signal Amplitude (2)
What units do we use to measure signal amplitude
Brief Review The decibel scale
Absolute vs relative measurement
Typical reference values
Howeverhellip
Linear vs logarithmic
Linear vs logarithmic (2)
Logarithmic Scale
Logarithmic Scale (2)
Combining the idea of logarithmic and relativehellip
Intensity vs Pressure
Extending the formula to pressure
Measuring Sound Frequencyperiod
Measuring Sound Frequencyperiod (2)
Phase Uniform Circular Motion
Initiating a sound waves that differ only in phase
Spatial variation in pressure wave
Spatial variation in pressure wave
Spatial variation in pressure wave (2)
Relation between frequency and wavelength
Learning Objectives
Graphic representation of sound
Same sound different graphs
Classification of sounds
Simple periodic sound
Simple periodic sound Graphic appearance
Complex periodic sounds
Complex periodic sounds Graphic appearance
Complex periodic sounds Graphic appearance (2)
Glottal Source
Amplitude vs Phase Spectrum
Amplitude vs Phase Spectrum (2)
(Complex) Aperiodic sounds
Aperiodic sounds Graphic appearance
Aperiodic sounds Graphic appearance (2)
Analysis of complex waves
Learning Objectives (2)
The ldquoenveloperdquo of a sound wave
Waveform envelope
Waveform envelope (2)
Spectrum envelope
Thought Question
Amplitude Spectrum Window Size
ldquoInstantaneousrdquo Amplitude Spectra
(Long Term) Average Amplitude Spectrum
Slide 90
Learning Objectives (3)
The Spectrogram
Building a spectrogram
Building a spectrogram
Building a spectrogram (2)
Two main types of spectrograms
Wide vs Narrow Band Spectrograms
Learning Objectives (4)
What is an ldquoAcousticrdquo Filter
Why might we be interested in filters
Kinds of frequency selective filters
Low Pass Filters
High Pass Filters
Band Pass Filter
Frequency Response Curve (FRC)
Operation of a filter on a signal
Learning Objectives (5)
Free vibration
Forced vibration
Forced vibration (2)
Resonance refers to
Back to the mass spring model
Acoustic Resonance
Acoustic Resonance (2)
Helmholtz Resonator
Actions of a Helmholtz Resonator
Other Acoustic Resonators Tube Resonators
Uniform tube closed at one end
Uniform tube closed at one end (2)
Uniform tube closed at one end
Comparing Helmholtz and tube resonators
Slide 122
Slide 123
Operation of a filter on a signal
NOTE Amplitude spectrum describes a soundFrequency response curve describes a filter
Learning Objectivesbull Define resonance free and forced vibrationbull Describe how the pendulum and spring mass models can
help explain resonancebull Outline how mass and stiffness influences the resonant
frequency of a mass spring systembull Outline how acoustic resonators behave like acoustic filtersbull Calculate resonant frequencies of a uniform tube based on
its physical dimensionsbull Describe how the wavelength of the sound determines the
resonant frequency of tube
Free vibration
bull objects tend to vibrate at a characteristic or resonant frequency (RF)
Forced vibration
bull A vibrating system can force a nearby system into vibration
bull The efficiency with which this is accomplished is related to the similarity in the resonant frequency (RF) of the two systems
Forced vibration
bull If the RF of the two systems are the same the amplitude of forced vibration will be large
bull If the RF of the two systems are quite different the amplitude of forced vibration will be small or nonexistent
Resonance refers to
bull The tendency for an object to vibrate at a particular frequency or frequencies
bull The ability of a vibrating system to force another system into vibration
Back to the mass spring model
bull Vibratory frequency of the mass spring determined byndash Massndash Stiffness of the spring
httpphetcoloradoeduensimulationmass-spring-lab
Acoustic Resonance
bull Ideas from mechanical resonance also applies to acoustic systems
bull Acoustic chambers will transmit sound frequencies with more or less efficiency depending upon the physical characteristics
bull Therefore they act as filters passing through (and even amplifying) some frequencies and attentuating others
Acoustic Resonance
bull And since they act as filters they have most of the same features of a filter even though we might use different names
bull Center frequency is often termed the resonant frequency
bull Frequency response curve often termed the resonance curve
Helmholtz Resonator
Actions of a Helmholtz Resonator
Stephen M Tasko
Other Acoustic Resonators Tube Resonators
bull Uniform tubes Factors that influence resonancendash Lengthndash Cross-sectional area along its lengthndash Whether it is closed at either or both ends
Uniform tube closed at one end
Uniform tube closed at one end
Stephen M Tasko
Uniform tube closed at one end
First resonance or formant
F1 = c4lWhere
c=speed of sound (35000 cmsec)l = length of the tube
males ~ 175 cmfemales ~ 14 cm
Higher resonantformant frequencies are odd multiples of F1
For examplebull F1 = (c4l )1
bull F2 = (c4l )3
bull F3 = (c4l )5
Comparing Helmholtz and tube resonators
Resonator Features
Sharply tuned Broadly tuned
Resonator Features
An example of the resonance characteristics of the human vocal tract
Frequency
Gain
SPPA 4030 Speech Science
Topic 1 The Speech Chain
The Speech Chain (Denes amp Pinson 1993)
What information is embedded in the speech signal
Branches of science employed to understand speech communication
Physical Quantities Review An Independent Learning Activity
Assignment 1
Topic 2 The Source-Filter Theory of Speech Production An Intr
Producing Speech
Source-Filter Theory of Speech Production
Vocal tract is a tube that can vary its shape
Source Filter Theory
Same Source Different Filter
Different Source Same Filters
Different Source Same Filters (Human)
Different Source Same Filters (Human) (2)
Different Source Same Filters (Human) (3)
Different Source Same Filters (Human) (4)
Different Source Same Filters (Non-Human)
Different Source Same Filters (Non-Human) (2)
Different Source Same Filters (Non-Human) If it quacks like a
Source Filter Theory Applied Alaryngeal Speech
Source-Filter Theory Applied Esophageal Insufflation Test
Source-Filter Theory Applied Tracheoesophageal (TE) Speech
Source Filter Theory Applied The Talkbox
Source-Filter Theory Applied The Talkbox
Topic 3 A Brief Review of Physical Acoustics
Spring Mass Model
What is sound
Sound-conducting media
Model of air molecule vibration (Time 1)
Model of air molecule vibration (Time 2)
Model of air molecule vibration (Time 3)
Model of air molecule vibration (Time 4)
Model of air molecule vibration (Time 5)
Model of air molecule vibration
Wave action of molecular motion
Amplitude waveform
Amplitude waveform (2)
Where is pressure in this model
Pressure waveform
Measuring Sound
Measuring Sound Signal Amplitude
Measuring Sound Signal Amplitude (2)
What units do we use to measure signal amplitude
Brief Review The decibel scale
Absolute vs relative measurement
Typical reference values
Howeverhellip
Linear vs logarithmic
Linear vs logarithmic (2)
Logarithmic Scale
Logarithmic Scale (2)
Combining the idea of logarithmic and relativehellip
Intensity vs Pressure
Extending the formula to pressure
Measuring Sound Frequencyperiod
Measuring Sound Frequencyperiod (2)
Phase Uniform Circular Motion
Initiating a sound waves that differ only in phase
Spatial variation in pressure wave
Spatial variation in pressure wave
Spatial variation in pressure wave (2)
Relation between frequency and wavelength
Learning Objectives
Graphic representation of sound
Same sound different graphs
Classification of sounds
Simple periodic sound
Simple periodic sound Graphic appearance
Complex periodic sounds
Complex periodic sounds Graphic appearance
Complex periodic sounds Graphic appearance (2)
Glottal Source
Amplitude vs Phase Spectrum
Amplitude vs Phase Spectrum (2)
(Complex) Aperiodic sounds
Aperiodic sounds Graphic appearance
Aperiodic sounds Graphic appearance (2)
Analysis of complex waves
Learning Objectives (2)
The ldquoenveloperdquo of a sound wave
Waveform envelope
Waveform envelope (2)
Spectrum envelope
Thought Question
Amplitude Spectrum Window Size
ldquoInstantaneousrdquo Amplitude Spectra
(Long Term) Average Amplitude Spectrum
Slide 90
Learning Objectives (3)
The Spectrogram
Building a spectrogram
Building a spectrogram
Building a spectrogram (2)
Two main types of spectrograms
Wide vs Narrow Band Spectrograms
Learning Objectives (4)
What is an ldquoAcousticrdquo Filter
Why might we be interested in filters
Kinds of frequency selective filters
Low Pass Filters
High Pass Filters
Band Pass Filter
Frequency Response Curve (FRC)
Operation of a filter on a signal
Learning Objectives (5)
Free vibration
Forced vibration
Forced vibration (2)
Resonance refers to
Back to the mass spring model
Acoustic Resonance
Acoustic Resonance (2)
Helmholtz Resonator
Actions of a Helmholtz Resonator
Other Acoustic Resonators Tube Resonators
Uniform tube closed at one end
Uniform tube closed at one end (2)
Uniform tube closed at one end
Comparing Helmholtz and tube resonators
Slide 122
Slide 123
Learning Objectivesbull Define resonance free and forced vibrationbull Describe how the pendulum and spring mass models can
help explain resonancebull Outline how mass and stiffness influences the resonant
frequency of a mass spring systembull Outline how acoustic resonators behave like acoustic filtersbull Calculate resonant frequencies of a uniform tube based on
its physical dimensionsbull Describe how the wavelength of the sound determines the
resonant frequency of tube
Free vibration
bull objects tend to vibrate at a characteristic or resonant frequency (RF)
Forced vibration
bull A vibrating system can force a nearby system into vibration
bull The efficiency with which this is accomplished is related to the similarity in the resonant frequency (RF) of the two systems
Forced vibration
bull If the RF of the two systems are the same the amplitude of forced vibration will be large
bull If the RF of the two systems are quite different the amplitude of forced vibration will be small or nonexistent
Resonance refers to
bull The tendency for an object to vibrate at a particular frequency or frequencies
bull The ability of a vibrating system to force another system into vibration
Back to the mass spring model
bull Vibratory frequency of the mass spring determined byndash Massndash Stiffness of the spring
httpphetcoloradoeduensimulationmass-spring-lab
Acoustic Resonance
bull Ideas from mechanical resonance also applies to acoustic systems
bull Acoustic chambers will transmit sound frequencies with more or less efficiency depending upon the physical characteristics
bull Therefore they act as filters passing through (and even amplifying) some frequencies and attentuating others
Acoustic Resonance
bull And since they act as filters they have most of the same features of a filter even though we might use different names
bull Center frequency is often termed the resonant frequency
bull Frequency response curve often termed the resonance curve
Helmholtz Resonator
Actions of a Helmholtz Resonator
Stephen M Tasko
Other Acoustic Resonators Tube Resonators
bull Uniform tubes Factors that influence resonancendash Lengthndash Cross-sectional area along its lengthndash Whether it is closed at either or both ends
Uniform tube closed at one end
Uniform tube closed at one end
Stephen M Tasko
Uniform tube closed at one end
First resonance or formant
F1 = c4lWhere
c=speed of sound (35000 cmsec)l = length of the tube
males ~ 175 cmfemales ~ 14 cm
Higher resonantformant frequencies are odd multiples of F1
For examplebull F1 = (c4l )1
bull F2 = (c4l )3
bull F3 = (c4l )5
Comparing Helmholtz and tube resonators
Resonator Features
Sharply tuned Broadly tuned
Resonator Features
An example of the resonance characteristics of the human vocal tract
Frequency
Gain
SPPA 4030 Speech Science
Topic 1 The Speech Chain
The Speech Chain (Denes amp Pinson 1993)
What information is embedded in the speech signal
Branches of science employed to understand speech communication
Physical Quantities Review An Independent Learning Activity
Assignment 1
Topic 2 The Source-Filter Theory of Speech Production An Intr
Producing Speech
Source-Filter Theory of Speech Production
Vocal tract is a tube that can vary its shape
Source Filter Theory
Same Source Different Filter
Different Source Same Filters
Different Source Same Filters (Human)
Different Source Same Filters (Human) (2)
Different Source Same Filters (Human) (3)
Different Source Same Filters (Human) (4)
Different Source Same Filters (Non-Human)
Different Source Same Filters (Non-Human) (2)
Different Source Same Filters (Non-Human) If it quacks like a
Source Filter Theory Applied Alaryngeal Speech
Source-Filter Theory Applied Esophageal Insufflation Test
Source-Filter Theory Applied Tracheoesophageal (TE) Speech
Source Filter Theory Applied The Talkbox
Source-Filter Theory Applied The Talkbox
Topic 3 A Brief Review of Physical Acoustics
Spring Mass Model
What is sound
Sound-conducting media
Model of air molecule vibration (Time 1)
Model of air molecule vibration (Time 2)
Model of air molecule vibration (Time 3)
Model of air molecule vibration (Time 4)
Model of air molecule vibration (Time 5)
Model of air molecule vibration
Wave action of molecular motion
Amplitude waveform
Amplitude waveform (2)
Where is pressure in this model
Pressure waveform
Measuring Sound
Measuring Sound Signal Amplitude
Measuring Sound Signal Amplitude (2)
What units do we use to measure signal amplitude
Brief Review The decibel scale
Absolute vs relative measurement
Typical reference values
Howeverhellip
Linear vs logarithmic
Linear vs logarithmic (2)
Logarithmic Scale
Logarithmic Scale (2)
Combining the idea of logarithmic and relativehellip
Intensity vs Pressure
Extending the formula to pressure
Measuring Sound Frequencyperiod
Measuring Sound Frequencyperiod (2)
Phase Uniform Circular Motion
Initiating a sound waves that differ only in phase
Spatial variation in pressure wave
Spatial variation in pressure wave
Spatial variation in pressure wave (2)
Relation between frequency and wavelength
Learning Objectives
Graphic representation of sound
Same sound different graphs
Classification of sounds
Simple periodic sound
Simple periodic sound Graphic appearance
Complex periodic sounds
Complex periodic sounds Graphic appearance
Complex periodic sounds Graphic appearance (2)
Glottal Source
Amplitude vs Phase Spectrum
Amplitude vs Phase Spectrum (2)
(Complex) Aperiodic sounds
Aperiodic sounds Graphic appearance
Aperiodic sounds Graphic appearance (2)
Analysis of complex waves
Learning Objectives (2)
The ldquoenveloperdquo of a sound wave
Waveform envelope
Waveform envelope (2)
Spectrum envelope
Thought Question
Amplitude Spectrum Window Size
ldquoInstantaneousrdquo Amplitude Spectra
(Long Term) Average Amplitude Spectrum
Slide 90
Learning Objectives (3)
The Spectrogram
Building a spectrogram
Building a spectrogram
Building a spectrogram (2)
Two main types of spectrograms
Wide vs Narrow Band Spectrograms
Learning Objectives (4)
What is an ldquoAcousticrdquo Filter
Why might we be interested in filters
Kinds of frequency selective filters
Low Pass Filters
High Pass Filters
Band Pass Filter
Frequency Response Curve (FRC)
Operation of a filter on a signal
Learning Objectives (5)
Free vibration
Forced vibration
Forced vibration (2)
Resonance refers to
Back to the mass spring model
Acoustic Resonance
Acoustic Resonance (2)
Helmholtz Resonator
Actions of a Helmholtz Resonator
Other Acoustic Resonators Tube Resonators
Uniform tube closed at one end
Uniform tube closed at one end (2)
Uniform tube closed at one end
Comparing Helmholtz and tube resonators
Slide 122
Slide 123
Free vibration
bull objects tend to vibrate at a characteristic or resonant frequency (RF)
Forced vibration
bull A vibrating system can force a nearby system into vibration
bull The efficiency with which this is accomplished is related to the similarity in the resonant frequency (RF) of the two systems
Forced vibration
bull If the RF of the two systems are the same the amplitude of forced vibration will be large
bull If the RF of the two systems are quite different the amplitude of forced vibration will be small or nonexistent
Resonance refers to
bull The tendency for an object to vibrate at a particular frequency or frequencies
bull The ability of a vibrating system to force another system into vibration
Back to the mass spring model
bull Vibratory frequency of the mass spring determined byndash Massndash Stiffness of the spring
httpphetcoloradoeduensimulationmass-spring-lab
Acoustic Resonance
bull Ideas from mechanical resonance also applies to acoustic systems
bull Acoustic chambers will transmit sound frequencies with more or less efficiency depending upon the physical characteristics
bull Therefore they act as filters passing through (and even amplifying) some frequencies and attentuating others
Acoustic Resonance
bull And since they act as filters they have most of the same features of a filter even though we might use different names
bull Center frequency is often termed the resonant frequency
bull Frequency response curve often termed the resonance curve
Helmholtz Resonator
Actions of a Helmholtz Resonator
Stephen M Tasko
Other Acoustic Resonators Tube Resonators
bull Uniform tubes Factors that influence resonancendash Lengthndash Cross-sectional area along its lengthndash Whether it is closed at either or both ends
Uniform tube closed at one end
Uniform tube closed at one end
Stephen M Tasko
Uniform tube closed at one end
First resonance or formant
F1 = c4lWhere
c=speed of sound (35000 cmsec)l = length of the tube
males ~ 175 cmfemales ~ 14 cm
Higher resonantformant frequencies are odd multiples of F1
For examplebull F1 = (c4l )1
bull F2 = (c4l )3
bull F3 = (c4l )5
Comparing Helmholtz and tube resonators
Resonator Features
Sharply tuned Broadly tuned
Resonator Features
An example of the resonance characteristics of the human vocal tract
Frequency
Gain
SPPA 4030 Speech Science
Topic 1 The Speech Chain
The Speech Chain (Denes amp Pinson 1993)
What information is embedded in the speech signal
Branches of science employed to understand speech communication
Physical Quantities Review An Independent Learning Activity
Assignment 1
Topic 2 The Source-Filter Theory of Speech Production An Intr
Producing Speech
Source-Filter Theory of Speech Production
Vocal tract is a tube that can vary its shape
Source Filter Theory
Same Source Different Filter
Different Source Same Filters
Different Source Same Filters (Human)
Different Source Same Filters (Human) (2)
Different Source Same Filters (Human) (3)
Different Source Same Filters (Human) (4)
Different Source Same Filters (Non-Human)
Different Source Same Filters (Non-Human) (2)
Different Source Same Filters (Non-Human) If it quacks like a
Source Filter Theory Applied Alaryngeal Speech
Source-Filter Theory Applied Esophageal Insufflation Test
Source-Filter Theory Applied Tracheoesophageal (TE) Speech
Source Filter Theory Applied The Talkbox
Source-Filter Theory Applied The Talkbox
Topic 3 A Brief Review of Physical Acoustics
Spring Mass Model
What is sound
Sound-conducting media
Model of air molecule vibration (Time 1)
Model of air molecule vibration (Time 2)
Model of air molecule vibration (Time 3)
Model of air molecule vibration (Time 4)
Model of air molecule vibration (Time 5)
Model of air molecule vibration
Wave action of molecular motion
Amplitude waveform
Amplitude waveform (2)
Where is pressure in this model
Pressure waveform
Measuring Sound
Measuring Sound Signal Amplitude
Measuring Sound Signal Amplitude (2)
What units do we use to measure signal amplitude
Brief Review The decibel scale
Absolute vs relative measurement
Typical reference values
Howeverhellip
Linear vs logarithmic
Linear vs logarithmic (2)
Logarithmic Scale
Logarithmic Scale (2)
Combining the idea of logarithmic and relativehellip
Intensity vs Pressure
Extending the formula to pressure
Measuring Sound Frequencyperiod
Measuring Sound Frequencyperiod (2)
Phase Uniform Circular Motion
Initiating a sound waves that differ only in phase
Spatial variation in pressure wave
Spatial variation in pressure wave
Spatial variation in pressure wave (2)
Relation between frequency and wavelength
Learning Objectives
Graphic representation of sound
Same sound different graphs
Classification of sounds
Simple periodic sound
Simple periodic sound Graphic appearance
Complex periodic sounds
Complex periodic sounds Graphic appearance
Complex periodic sounds Graphic appearance (2)
Glottal Source
Amplitude vs Phase Spectrum
Amplitude vs Phase Spectrum (2)
(Complex) Aperiodic sounds
Aperiodic sounds Graphic appearance
Aperiodic sounds Graphic appearance (2)
Analysis of complex waves
Learning Objectives (2)
The ldquoenveloperdquo of a sound wave
Waveform envelope
Waveform envelope (2)
Spectrum envelope
Thought Question
Amplitude Spectrum Window Size
ldquoInstantaneousrdquo Amplitude Spectra
(Long Term) Average Amplitude Spectrum
Slide 90
Learning Objectives (3)
The Spectrogram
Building a spectrogram
Building a spectrogram
Building a spectrogram (2)
Two main types of spectrograms
Wide vs Narrow Band Spectrograms
Learning Objectives (4)
What is an ldquoAcousticrdquo Filter
Why might we be interested in filters
Kinds of frequency selective filters
Low Pass Filters
High Pass Filters
Band Pass Filter
Frequency Response Curve (FRC)
Operation of a filter on a signal
Learning Objectives (5)
Free vibration
Forced vibration
Forced vibration (2)
Resonance refers to
Back to the mass spring model
Acoustic Resonance
Acoustic Resonance (2)
Helmholtz Resonator
Actions of a Helmholtz Resonator
Other Acoustic Resonators Tube Resonators
Uniform tube closed at one end
Uniform tube closed at one end (2)
Uniform tube closed at one end
Comparing Helmholtz and tube resonators
Slide 122
Slide 123
Forced vibration
bull A vibrating system can force a nearby system into vibration
bull The efficiency with which this is accomplished is related to the similarity in the resonant frequency (RF) of the two systems
Forced vibration
bull If the RF of the two systems are the same the amplitude of forced vibration will be large
bull If the RF of the two systems are quite different the amplitude of forced vibration will be small or nonexistent
Resonance refers to
bull The tendency for an object to vibrate at a particular frequency or frequencies
bull The ability of a vibrating system to force another system into vibration
Back to the mass spring model
bull Vibratory frequency of the mass spring determined byndash Massndash Stiffness of the spring
httpphetcoloradoeduensimulationmass-spring-lab
Acoustic Resonance
bull Ideas from mechanical resonance also applies to acoustic systems
bull Acoustic chambers will transmit sound frequencies with more or less efficiency depending upon the physical characteristics
bull Therefore they act as filters passing through (and even amplifying) some frequencies and attentuating others
Acoustic Resonance
bull And since they act as filters they have most of the same features of a filter even though we might use different names
bull Center frequency is often termed the resonant frequency
bull Frequency response curve often termed the resonance curve
Helmholtz Resonator
Actions of a Helmholtz Resonator
Stephen M Tasko
Other Acoustic Resonators Tube Resonators
bull Uniform tubes Factors that influence resonancendash Lengthndash Cross-sectional area along its lengthndash Whether it is closed at either or both ends
Uniform tube closed at one end
Uniform tube closed at one end
Stephen M Tasko
Uniform tube closed at one end
First resonance or formant
F1 = c4lWhere
c=speed of sound (35000 cmsec)l = length of the tube
males ~ 175 cmfemales ~ 14 cm
Higher resonantformant frequencies are odd multiples of F1
For examplebull F1 = (c4l )1
bull F2 = (c4l )3
bull F3 = (c4l )5
Comparing Helmholtz and tube resonators
Resonator Features
Sharply tuned Broadly tuned
Resonator Features
An example of the resonance characteristics of the human vocal tract
Frequency
Gain
SPPA 4030 Speech Science
Topic 1 The Speech Chain
The Speech Chain (Denes amp Pinson 1993)
What information is embedded in the speech signal
Branches of science employed to understand speech communication
Physical Quantities Review An Independent Learning Activity
Assignment 1
Topic 2 The Source-Filter Theory of Speech Production An Intr
Producing Speech
Source-Filter Theory of Speech Production
Vocal tract is a tube that can vary its shape
Source Filter Theory
Same Source Different Filter
Different Source Same Filters
Different Source Same Filters (Human)
Different Source Same Filters (Human) (2)
Different Source Same Filters (Human) (3)
Different Source Same Filters (Human) (4)
Different Source Same Filters (Non-Human)
Different Source Same Filters (Non-Human) (2)
Different Source Same Filters (Non-Human) If it quacks like a
Source Filter Theory Applied Alaryngeal Speech
Source-Filter Theory Applied Esophageal Insufflation Test
Source-Filter Theory Applied Tracheoesophageal (TE) Speech
Source Filter Theory Applied The Talkbox
Source-Filter Theory Applied The Talkbox
Topic 3 A Brief Review of Physical Acoustics
Spring Mass Model
What is sound
Sound-conducting media
Model of air molecule vibration (Time 1)
Model of air molecule vibration (Time 2)
Model of air molecule vibration (Time 3)
Model of air molecule vibration (Time 4)
Model of air molecule vibration (Time 5)
Model of air molecule vibration
Wave action of molecular motion
Amplitude waveform
Amplitude waveform (2)
Where is pressure in this model
Pressure waveform
Measuring Sound
Measuring Sound Signal Amplitude
Measuring Sound Signal Amplitude (2)
What units do we use to measure signal amplitude
Brief Review The decibel scale
Absolute vs relative measurement
Typical reference values
Howeverhellip
Linear vs logarithmic
Linear vs logarithmic (2)
Logarithmic Scale
Logarithmic Scale (2)
Combining the idea of logarithmic and relativehellip
Intensity vs Pressure
Extending the formula to pressure
Measuring Sound Frequencyperiod
Measuring Sound Frequencyperiod (2)
Phase Uniform Circular Motion
Initiating a sound waves that differ only in phase
Spatial variation in pressure wave
Spatial variation in pressure wave
Spatial variation in pressure wave (2)
Relation between frequency and wavelength
Learning Objectives
Graphic representation of sound
Same sound different graphs
Classification of sounds
Simple periodic sound
Simple periodic sound Graphic appearance
Complex periodic sounds
Complex periodic sounds Graphic appearance
Complex periodic sounds Graphic appearance (2)
Glottal Source
Amplitude vs Phase Spectrum
Amplitude vs Phase Spectrum (2)
(Complex) Aperiodic sounds
Aperiodic sounds Graphic appearance
Aperiodic sounds Graphic appearance (2)
Analysis of complex waves
Learning Objectives (2)
The ldquoenveloperdquo of a sound wave
Waveform envelope
Waveform envelope (2)
Spectrum envelope
Thought Question
Amplitude Spectrum Window Size
ldquoInstantaneousrdquo Amplitude Spectra
(Long Term) Average Amplitude Spectrum
Slide 90
Learning Objectives (3)
The Spectrogram
Building a spectrogram
Building a spectrogram
Building a spectrogram (2)
Two main types of spectrograms
Wide vs Narrow Band Spectrograms
Learning Objectives (4)
What is an ldquoAcousticrdquo Filter
Why might we be interested in filters
Kinds of frequency selective filters
Low Pass Filters
High Pass Filters
Band Pass Filter
Frequency Response Curve (FRC)
Operation of a filter on a signal
Learning Objectives (5)
Free vibration
Forced vibration
Forced vibration (2)
Resonance refers to
Back to the mass spring model
Acoustic Resonance
Acoustic Resonance (2)
Helmholtz Resonator
Actions of a Helmholtz Resonator
Other Acoustic Resonators Tube Resonators
Uniform tube closed at one end
Uniform tube closed at one end (2)
Uniform tube closed at one end
Comparing Helmholtz and tube resonators
Slide 122
Slide 123
Forced vibration
bull If the RF of the two systems are the same the amplitude of forced vibration will be large
bull If the RF of the two systems are quite different the amplitude of forced vibration will be small or nonexistent
Resonance refers to
bull The tendency for an object to vibrate at a particular frequency or frequencies
bull The ability of a vibrating system to force another system into vibration
Back to the mass spring model
bull Vibratory frequency of the mass spring determined byndash Massndash Stiffness of the spring
httpphetcoloradoeduensimulationmass-spring-lab
Acoustic Resonance
bull Ideas from mechanical resonance also applies to acoustic systems
bull Acoustic chambers will transmit sound frequencies with more or less efficiency depending upon the physical characteristics
bull Therefore they act as filters passing through (and even amplifying) some frequencies and attentuating others
Acoustic Resonance
bull And since they act as filters they have most of the same features of a filter even though we might use different names
bull Center frequency is often termed the resonant frequency
bull Frequency response curve often termed the resonance curve
Helmholtz Resonator
Actions of a Helmholtz Resonator
Stephen M Tasko
Other Acoustic Resonators Tube Resonators
bull Uniform tubes Factors that influence resonancendash Lengthndash Cross-sectional area along its lengthndash Whether it is closed at either or both ends
Uniform tube closed at one end
Uniform tube closed at one end
Stephen M Tasko
Uniform tube closed at one end
First resonance or formant
F1 = c4lWhere
c=speed of sound (35000 cmsec)l = length of the tube
males ~ 175 cmfemales ~ 14 cm
Higher resonantformant frequencies are odd multiples of F1
For examplebull F1 = (c4l )1
bull F2 = (c4l )3
bull F3 = (c4l )5
Comparing Helmholtz and tube resonators
Resonator Features
Sharply tuned Broadly tuned
Resonator Features
An example of the resonance characteristics of the human vocal tract
Frequency
Gain
SPPA 4030 Speech Science
Topic 1 The Speech Chain
The Speech Chain (Denes amp Pinson 1993)
What information is embedded in the speech signal
Branches of science employed to understand speech communication
Physical Quantities Review An Independent Learning Activity
Assignment 1
Topic 2 The Source-Filter Theory of Speech Production An Intr
Producing Speech
Source-Filter Theory of Speech Production
Vocal tract is a tube that can vary its shape
Source Filter Theory
Same Source Different Filter
Different Source Same Filters
Different Source Same Filters (Human)
Different Source Same Filters (Human) (2)
Different Source Same Filters (Human) (3)
Different Source Same Filters (Human) (4)
Different Source Same Filters (Non-Human)
Different Source Same Filters (Non-Human) (2)
Different Source Same Filters (Non-Human) If it quacks like a
Source Filter Theory Applied Alaryngeal Speech
Source-Filter Theory Applied Esophageal Insufflation Test
Source-Filter Theory Applied Tracheoesophageal (TE) Speech
Source Filter Theory Applied The Talkbox
Source-Filter Theory Applied The Talkbox
Topic 3 A Brief Review of Physical Acoustics
Spring Mass Model
What is sound
Sound-conducting media
Model of air molecule vibration (Time 1)
Model of air molecule vibration (Time 2)
Model of air molecule vibration (Time 3)
Model of air molecule vibration (Time 4)
Model of air molecule vibration (Time 5)
Model of air molecule vibration
Wave action of molecular motion
Amplitude waveform
Amplitude waveform (2)
Where is pressure in this model
Pressure waveform
Measuring Sound
Measuring Sound Signal Amplitude
Measuring Sound Signal Amplitude (2)
What units do we use to measure signal amplitude
Brief Review The decibel scale
Absolute vs relative measurement
Typical reference values
Howeverhellip
Linear vs logarithmic
Linear vs logarithmic (2)
Logarithmic Scale
Logarithmic Scale (2)
Combining the idea of logarithmic and relativehellip
Intensity vs Pressure
Extending the formula to pressure
Measuring Sound Frequencyperiod
Measuring Sound Frequencyperiod (2)
Phase Uniform Circular Motion
Initiating a sound waves that differ only in phase
Spatial variation in pressure wave
Spatial variation in pressure wave
Spatial variation in pressure wave (2)
Relation between frequency and wavelength
Learning Objectives
Graphic representation of sound
Same sound different graphs
Classification of sounds
Simple periodic sound
Simple periodic sound Graphic appearance
Complex periodic sounds
Complex periodic sounds Graphic appearance
Complex periodic sounds Graphic appearance (2)
Glottal Source
Amplitude vs Phase Spectrum
Amplitude vs Phase Spectrum (2)
(Complex) Aperiodic sounds
Aperiodic sounds Graphic appearance
Aperiodic sounds Graphic appearance (2)
Analysis of complex waves
Learning Objectives (2)
The ldquoenveloperdquo of a sound wave
Waveform envelope
Waveform envelope (2)
Spectrum envelope
Thought Question
Amplitude Spectrum Window Size
ldquoInstantaneousrdquo Amplitude Spectra
(Long Term) Average Amplitude Spectrum
Slide 90
Learning Objectives (3)
The Spectrogram
Building a spectrogram
Building a spectrogram
Building a spectrogram (2)
Two main types of spectrograms
Wide vs Narrow Band Spectrograms
Learning Objectives (4)
What is an ldquoAcousticrdquo Filter
Why might we be interested in filters
Kinds of frequency selective filters
Low Pass Filters
High Pass Filters
Band Pass Filter
Frequency Response Curve (FRC)
Operation of a filter on a signal
Learning Objectives (5)
Free vibration
Forced vibration
Forced vibration (2)
Resonance refers to
Back to the mass spring model
Acoustic Resonance
Acoustic Resonance (2)
Helmholtz Resonator
Actions of a Helmholtz Resonator
Other Acoustic Resonators Tube Resonators
Uniform tube closed at one end
Uniform tube closed at one end (2)
Uniform tube closed at one end
Comparing Helmholtz and tube resonators
Slide 122
Slide 123
Resonance refers to
bull The tendency for an object to vibrate at a particular frequency or frequencies
bull The ability of a vibrating system to force another system into vibration
Back to the mass spring model
bull Vibratory frequency of the mass spring determined byndash Massndash Stiffness of the spring
httpphetcoloradoeduensimulationmass-spring-lab
Acoustic Resonance
bull Ideas from mechanical resonance also applies to acoustic systems
bull Acoustic chambers will transmit sound frequencies with more or less efficiency depending upon the physical characteristics
bull Therefore they act as filters passing through (and even amplifying) some frequencies and attentuating others
Acoustic Resonance
bull And since they act as filters they have most of the same features of a filter even though we might use different names
bull Center frequency is often termed the resonant frequency
bull Frequency response curve often termed the resonance curve
Helmholtz Resonator
Actions of a Helmholtz Resonator
Stephen M Tasko
Other Acoustic Resonators Tube Resonators
bull Uniform tubes Factors that influence resonancendash Lengthndash Cross-sectional area along its lengthndash Whether it is closed at either or both ends
Uniform tube closed at one end
Uniform tube closed at one end
Stephen M Tasko
Uniform tube closed at one end
First resonance or formant
F1 = c4lWhere
c=speed of sound (35000 cmsec)l = length of the tube
males ~ 175 cmfemales ~ 14 cm
Higher resonantformant frequencies are odd multiples of F1
For examplebull F1 = (c4l )1
bull F2 = (c4l )3
bull F3 = (c4l )5
Comparing Helmholtz and tube resonators
Resonator Features
Sharply tuned Broadly tuned
Resonator Features
An example of the resonance characteristics of the human vocal tract
Frequency
Gain
SPPA 4030 Speech Science
Topic 1 The Speech Chain
The Speech Chain (Denes amp Pinson 1993)
What information is embedded in the speech signal
Branches of science employed to understand speech communication
Physical Quantities Review An Independent Learning Activity
Assignment 1
Topic 2 The Source-Filter Theory of Speech Production An Intr
Producing Speech
Source-Filter Theory of Speech Production
Vocal tract is a tube that can vary its shape
Source Filter Theory
Same Source Different Filter
Different Source Same Filters
Different Source Same Filters (Human)
Different Source Same Filters (Human) (2)
Different Source Same Filters (Human) (3)
Different Source Same Filters (Human) (4)
Different Source Same Filters (Non-Human)
Different Source Same Filters (Non-Human) (2)
Different Source Same Filters (Non-Human) If it quacks like a
Source Filter Theory Applied Alaryngeal Speech
Source-Filter Theory Applied Esophageal Insufflation Test
Source-Filter Theory Applied Tracheoesophageal (TE) Speech
Source Filter Theory Applied The Talkbox
Source-Filter Theory Applied The Talkbox
Topic 3 A Brief Review of Physical Acoustics
Spring Mass Model
What is sound
Sound-conducting media
Model of air molecule vibration (Time 1)
Model of air molecule vibration (Time 2)
Model of air molecule vibration (Time 3)
Model of air molecule vibration (Time 4)
Model of air molecule vibration (Time 5)
Model of air molecule vibration
Wave action of molecular motion
Amplitude waveform
Amplitude waveform (2)
Where is pressure in this model
Pressure waveform
Measuring Sound
Measuring Sound Signal Amplitude
Measuring Sound Signal Amplitude (2)
What units do we use to measure signal amplitude
Brief Review The decibel scale
Absolute vs relative measurement
Typical reference values
Howeverhellip
Linear vs logarithmic
Linear vs logarithmic (2)
Logarithmic Scale
Logarithmic Scale (2)
Combining the idea of logarithmic and relativehellip
Intensity vs Pressure
Extending the formula to pressure
Measuring Sound Frequencyperiod
Measuring Sound Frequencyperiod (2)
Phase Uniform Circular Motion
Initiating a sound waves that differ only in phase
Spatial variation in pressure wave
Spatial variation in pressure wave
Spatial variation in pressure wave (2)
Relation between frequency and wavelength
Learning Objectives
Graphic representation of sound
Same sound different graphs
Classification of sounds
Simple periodic sound
Simple periodic sound Graphic appearance
Complex periodic sounds
Complex periodic sounds Graphic appearance
Complex periodic sounds Graphic appearance (2)
Glottal Source
Amplitude vs Phase Spectrum
Amplitude vs Phase Spectrum (2)
(Complex) Aperiodic sounds
Aperiodic sounds Graphic appearance
Aperiodic sounds Graphic appearance (2)
Analysis of complex waves
Learning Objectives (2)
The ldquoenveloperdquo of a sound wave
Waveform envelope
Waveform envelope (2)
Spectrum envelope
Thought Question
Amplitude Spectrum Window Size
ldquoInstantaneousrdquo Amplitude Spectra
(Long Term) Average Amplitude Spectrum
Slide 90
Learning Objectives (3)
The Spectrogram
Building a spectrogram
Building a spectrogram
Building a spectrogram (2)
Two main types of spectrograms
Wide vs Narrow Band Spectrograms
Learning Objectives (4)
What is an ldquoAcousticrdquo Filter
Why might we be interested in filters
Kinds of frequency selective filters
Low Pass Filters
High Pass Filters
Band Pass Filter
Frequency Response Curve (FRC)
Operation of a filter on a signal
Learning Objectives (5)
Free vibration
Forced vibration
Forced vibration (2)
Resonance refers to
Back to the mass spring model
Acoustic Resonance
Acoustic Resonance (2)
Helmholtz Resonator
Actions of a Helmholtz Resonator
Other Acoustic Resonators Tube Resonators
Uniform tube closed at one end
Uniform tube closed at one end (2)
Uniform tube closed at one end
Comparing Helmholtz and tube resonators
Slide 122
Slide 123
Back to the mass spring model
bull Vibratory frequency of the mass spring determined byndash Massndash Stiffness of the spring
httpphetcoloradoeduensimulationmass-spring-lab
Acoustic Resonance
bull Ideas from mechanical resonance also applies to acoustic systems
bull Acoustic chambers will transmit sound frequencies with more or less efficiency depending upon the physical characteristics
bull Therefore they act as filters passing through (and even amplifying) some frequencies and attentuating others
Acoustic Resonance
bull And since they act as filters they have most of the same features of a filter even though we might use different names
bull Center frequency is often termed the resonant frequency
bull Frequency response curve often termed the resonance curve
Helmholtz Resonator
Actions of a Helmholtz Resonator
Stephen M Tasko
Other Acoustic Resonators Tube Resonators
bull Uniform tubes Factors that influence resonancendash Lengthndash Cross-sectional area along its lengthndash Whether it is closed at either or both ends
Uniform tube closed at one end
Uniform tube closed at one end
Stephen M Tasko
Uniform tube closed at one end
First resonance or formant
F1 = c4lWhere
c=speed of sound (35000 cmsec)l = length of the tube
males ~ 175 cmfemales ~ 14 cm
Higher resonantformant frequencies are odd multiples of F1
For examplebull F1 = (c4l )1
bull F2 = (c4l )3
bull F3 = (c4l )5
Comparing Helmholtz and tube resonators
Resonator Features
Sharply tuned Broadly tuned
Resonator Features
An example of the resonance characteristics of the human vocal tract
Frequency
Gain
SPPA 4030 Speech Science
Topic 1 The Speech Chain
The Speech Chain (Denes amp Pinson 1993)
What information is embedded in the speech signal
Branches of science employed to understand speech communication
Physical Quantities Review An Independent Learning Activity
Assignment 1
Topic 2 The Source-Filter Theory of Speech Production An Intr
Producing Speech
Source-Filter Theory of Speech Production
Vocal tract is a tube that can vary its shape
Source Filter Theory
Same Source Different Filter
Different Source Same Filters
Different Source Same Filters (Human)
Different Source Same Filters (Human) (2)
Different Source Same Filters (Human) (3)
Different Source Same Filters (Human) (4)
Different Source Same Filters (Non-Human)
Different Source Same Filters (Non-Human) (2)
Different Source Same Filters (Non-Human) If it quacks like a
Source Filter Theory Applied Alaryngeal Speech
Source-Filter Theory Applied Esophageal Insufflation Test
Source-Filter Theory Applied Tracheoesophageal (TE) Speech
Source Filter Theory Applied The Talkbox
Source-Filter Theory Applied The Talkbox
Topic 3 A Brief Review of Physical Acoustics
Spring Mass Model
What is sound
Sound-conducting media
Model of air molecule vibration (Time 1)
Model of air molecule vibration (Time 2)
Model of air molecule vibration (Time 3)
Model of air molecule vibration (Time 4)
Model of air molecule vibration (Time 5)
Model of air molecule vibration
Wave action of molecular motion
Amplitude waveform
Amplitude waveform (2)
Where is pressure in this model
Pressure waveform
Measuring Sound
Measuring Sound Signal Amplitude
Measuring Sound Signal Amplitude (2)
What units do we use to measure signal amplitude
Brief Review The decibel scale
Absolute vs relative measurement
Typical reference values
Howeverhellip
Linear vs logarithmic
Linear vs logarithmic (2)
Logarithmic Scale
Logarithmic Scale (2)
Combining the idea of logarithmic and relativehellip
Intensity vs Pressure
Extending the formula to pressure
Measuring Sound Frequencyperiod
Measuring Sound Frequencyperiod (2)
Phase Uniform Circular Motion
Initiating a sound waves that differ only in phase
Spatial variation in pressure wave
Spatial variation in pressure wave
Spatial variation in pressure wave (2)
Relation between frequency and wavelength
Learning Objectives
Graphic representation of sound
Same sound different graphs
Classification of sounds
Simple periodic sound
Simple periodic sound Graphic appearance
Complex periodic sounds
Complex periodic sounds Graphic appearance
Complex periodic sounds Graphic appearance (2)
Glottal Source
Amplitude vs Phase Spectrum
Amplitude vs Phase Spectrum (2)
(Complex) Aperiodic sounds
Aperiodic sounds Graphic appearance
Aperiodic sounds Graphic appearance (2)
Analysis of complex waves
Learning Objectives (2)
The ldquoenveloperdquo of a sound wave
Waveform envelope
Waveform envelope (2)
Spectrum envelope
Thought Question
Amplitude Spectrum Window Size
ldquoInstantaneousrdquo Amplitude Spectra
(Long Term) Average Amplitude Spectrum
Slide 90
Learning Objectives (3)
The Spectrogram
Building a spectrogram
Building a spectrogram
Building a spectrogram (2)
Two main types of spectrograms
Wide vs Narrow Band Spectrograms
Learning Objectives (4)
What is an ldquoAcousticrdquo Filter
Why might we be interested in filters
Kinds of frequency selective filters
Low Pass Filters
High Pass Filters
Band Pass Filter
Frequency Response Curve (FRC)
Operation of a filter on a signal
Learning Objectives (5)
Free vibration
Forced vibration
Forced vibration (2)
Resonance refers to
Back to the mass spring model
Acoustic Resonance
Acoustic Resonance (2)
Helmholtz Resonator
Actions of a Helmholtz Resonator
Other Acoustic Resonators Tube Resonators
Uniform tube closed at one end
Uniform tube closed at one end (2)
Uniform tube closed at one end
Comparing Helmholtz and tube resonators
Slide 122
Slide 123
Acoustic Resonance
bull Ideas from mechanical resonance also applies to acoustic systems
bull Acoustic chambers will transmit sound frequencies with more or less efficiency depending upon the physical characteristics
bull Therefore they act as filters passing through (and even amplifying) some frequencies and attentuating others
Acoustic Resonance
bull And since they act as filters they have most of the same features of a filter even though we might use different names
bull Center frequency is often termed the resonant frequency
bull Frequency response curve often termed the resonance curve
Helmholtz Resonator
Actions of a Helmholtz Resonator
Stephen M Tasko
Other Acoustic Resonators Tube Resonators
bull Uniform tubes Factors that influence resonancendash Lengthndash Cross-sectional area along its lengthndash Whether it is closed at either or both ends
Uniform tube closed at one end
Uniform tube closed at one end
Stephen M Tasko
Uniform tube closed at one end
First resonance or formant
F1 = c4lWhere
c=speed of sound (35000 cmsec)l = length of the tube
males ~ 175 cmfemales ~ 14 cm
Higher resonantformant frequencies are odd multiples of F1
For examplebull F1 = (c4l )1
bull F2 = (c4l )3
bull F3 = (c4l )5
Comparing Helmholtz and tube resonators
Resonator Features
Sharply tuned Broadly tuned
Resonator Features
An example of the resonance characteristics of the human vocal tract
Frequency
Gain
SPPA 4030 Speech Science
Topic 1 The Speech Chain
The Speech Chain (Denes amp Pinson 1993)
What information is embedded in the speech signal
Branches of science employed to understand speech communication
Physical Quantities Review An Independent Learning Activity
Assignment 1
Topic 2 The Source-Filter Theory of Speech Production An Intr
Producing Speech
Source-Filter Theory of Speech Production
Vocal tract is a tube that can vary its shape
Source Filter Theory
Same Source Different Filter
Different Source Same Filters
Different Source Same Filters (Human)
Different Source Same Filters (Human) (2)
Different Source Same Filters (Human) (3)
Different Source Same Filters (Human) (4)
Different Source Same Filters (Non-Human)
Different Source Same Filters (Non-Human) (2)
Different Source Same Filters (Non-Human) If it quacks like a
Source Filter Theory Applied Alaryngeal Speech
Source-Filter Theory Applied Esophageal Insufflation Test
Source-Filter Theory Applied Tracheoesophageal (TE) Speech
Source Filter Theory Applied The Talkbox
Source-Filter Theory Applied The Talkbox
Topic 3 A Brief Review of Physical Acoustics
Spring Mass Model
What is sound
Sound-conducting media
Model of air molecule vibration (Time 1)
Model of air molecule vibration (Time 2)
Model of air molecule vibration (Time 3)
Model of air molecule vibration (Time 4)
Model of air molecule vibration (Time 5)
Model of air molecule vibration
Wave action of molecular motion
Amplitude waveform
Amplitude waveform (2)
Where is pressure in this model
Pressure waveform
Measuring Sound
Measuring Sound Signal Amplitude
Measuring Sound Signal Amplitude (2)
What units do we use to measure signal amplitude
Brief Review The decibel scale
Absolute vs relative measurement
Typical reference values
Howeverhellip
Linear vs logarithmic
Linear vs logarithmic (2)
Logarithmic Scale
Logarithmic Scale (2)
Combining the idea of logarithmic and relativehellip
Intensity vs Pressure
Extending the formula to pressure
Measuring Sound Frequencyperiod
Measuring Sound Frequencyperiod (2)
Phase Uniform Circular Motion
Initiating a sound waves that differ only in phase
Spatial variation in pressure wave
Spatial variation in pressure wave
Spatial variation in pressure wave (2)
Relation between frequency and wavelength
Learning Objectives
Graphic representation of sound
Same sound different graphs
Classification of sounds
Simple periodic sound
Simple periodic sound Graphic appearance
Complex periodic sounds
Complex periodic sounds Graphic appearance
Complex periodic sounds Graphic appearance (2)
Glottal Source
Amplitude vs Phase Spectrum
Amplitude vs Phase Spectrum (2)
(Complex) Aperiodic sounds
Aperiodic sounds Graphic appearance
Aperiodic sounds Graphic appearance (2)
Analysis of complex waves
Learning Objectives (2)
The ldquoenveloperdquo of a sound wave
Waveform envelope
Waveform envelope (2)
Spectrum envelope
Thought Question
Amplitude Spectrum Window Size
ldquoInstantaneousrdquo Amplitude Spectra
(Long Term) Average Amplitude Spectrum
Slide 90
Learning Objectives (3)
The Spectrogram
Building a spectrogram
Building a spectrogram
Building a spectrogram (2)
Two main types of spectrograms
Wide vs Narrow Band Spectrograms
Learning Objectives (4)
What is an ldquoAcousticrdquo Filter
Why might we be interested in filters
Kinds of frequency selective filters
Low Pass Filters
High Pass Filters
Band Pass Filter
Frequency Response Curve (FRC)
Operation of a filter on a signal
Learning Objectives (5)
Free vibration
Forced vibration
Forced vibration (2)
Resonance refers to
Back to the mass spring model
Acoustic Resonance
Acoustic Resonance (2)
Helmholtz Resonator
Actions of a Helmholtz Resonator
Other Acoustic Resonators Tube Resonators
Uniform tube closed at one end
Uniform tube closed at one end (2)
Uniform tube closed at one end
Comparing Helmholtz and tube resonators
Slide 122
Slide 123
Acoustic Resonance
bull And since they act as filters they have most of the same features of a filter even though we might use different names
bull Center frequency is often termed the resonant frequency
bull Frequency response curve often termed the resonance curve
Helmholtz Resonator
Actions of a Helmholtz Resonator
Stephen M Tasko
Other Acoustic Resonators Tube Resonators
bull Uniform tubes Factors that influence resonancendash Lengthndash Cross-sectional area along its lengthndash Whether it is closed at either or both ends
Uniform tube closed at one end
Uniform tube closed at one end
Stephen M Tasko
Uniform tube closed at one end
First resonance or formant
F1 = c4lWhere
c=speed of sound (35000 cmsec)l = length of the tube
males ~ 175 cmfemales ~ 14 cm
Higher resonantformant frequencies are odd multiples of F1
For examplebull F1 = (c4l )1
bull F2 = (c4l )3
bull F3 = (c4l )5
Comparing Helmholtz and tube resonators
Resonator Features
Sharply tuned Broadly tuned
Resonator Features
An example of the resonance characteristics of the human vocal tract
Frequency
Gain
SPPA 4030 Speech Science
Topic 1 The Speech Chain
The Speech Chain (Denes amp Pinson 1993)
What information is embedded in the speech signal
Branches of science employed to understand speech communication
Physical Quantities Review An Independent Learning Activity
Assignment 1
Topic 2 The Source-Filter Theory of Speech Production An Intr
Producing Speech
Source-Filter Theory of Speech Production
Vocal tract is a tube that can vary its shape
Source Filter Theory
Same Source Different Filter
Different Source Same Filters
Different Source Same Filters (Human)
Different Source Same Filters (Human) (2)
Different Source Same Filters (Human) (3)
Different Source Same Filters (Human) (4)
Different Source Same Filters (Non-Human)
Different Source Same Filters (Non-Human) (2)
Different Source Same Filters (Non-Human) If it quacks like a
Source Filter Theory Applied Alaryngeal Speech
Source-Filter Theory Applied Esophageal Insufflation Test
Source-Filter Theory Applied Tracheoesophageal (TE) Speech
Source Filter Theory Applied The Talkbox
Source-Filter Theory Applied The Talkbox
Topic 3 A Brief Review of Physical Acoustics
Spring Mass Model
What is sound
Sound-conducting media
Model of air molecule vibration (Time 1)
Model of air molecule vibration (Time 2)
Model of air molecule vibration (Time 3)
Model of air molecule vibration (Time 4)
Model of air molecule vibration (Time 5)
Model of air molecule vibration
Wave action of molecular motion
Amplitude waveform
Amplitude waveform (2)
Where is pressure in this model
Pressure waveform
Measuring Sound
Measuring Sound Signal Amplitude
Measuring Sound Signal Amplitude (2)
What units do we use to measure signal amplitude
Brief Review The decibel scale
Absolute vs relative measurement
Typical reference values
Howeverhellip
Linear vs logarithmic
Linear vs logarithmic (2)
Logarithmic Scale
Logarithmic Scale (2)
Combining the idea of logarithmic and relativehellip
Intensity vs Pressure
Extending the formula to pressure
Measuring Sound Frequencyperiod
Measuring Sound Frequencyperiod (2)
Phase Uniform Circular Motion
Initiating a sound waves that differ only in phase
Spatial variation in pressure wave
Spatial variation in pressure wave
Spatial variation in pressure wave (2)
Relation between frequency and wavelength
Learning Objectives
Graphic representation of sound
Same sound different graphs
Classification of sounds
Simple periodic sound
Simple periodic sound Graphic appearance
Complex periodic sounds
Complex periodic sounds Graphic appearance
Complex periodic sounds Graphic appearance (2)
Glottal Source
Amplitude vs Phase Spectrum
Amplitude vs Phase Spectrum (2)
(Complex) Aperiodic sounds
Aperiodic sounds Graphic appearance
Aperiodic sounds Graphic appearance (2)
Analysis of complex waves
Learning Objectives (2)
The ldquoenveloperdquo of a sound wave
Waveform envelope
Waveform envelope (2)
Spectrum envelope
Thought Question
Amplitude Spectrum Window Size
ldquoInstantaneousrdquo Amplitude Spectra
(Long Term) Average Amplitude Spectrum
Slide 90
Learning Objectives (3)
The Spectrogram
Building a spectrogram
Building a spectrogram
Building a spectrogram (2)
Two main types of spectrograms
Wide vs Narrow Band Spectrograms
Learning Objectives (4)
What is an ldquoAcousticrdquo Filter
Why might we be interested in filters
Kinds of frequency selective filters
Low Pass Filters
High Pass Filters
Band Pass Filter
Frequency Response Curve (FRC)
Operation of a filter on a signal
Learning Objectives (5)
Free vibration
Forced vibration
Forced vibration (2)
Resonance refers to
Back to the mass spring model
Acoustic Resonance
Acoustic Resonance (2)
Helmholtz Resonator
Actions of a Helmholtz Resonator
Other Acoustic Resonators Tube Resonators
Uniform tube closed at one end
Uniform tube closed at one end (2)
Uniform tube closed at one end
Comparing Helmholtz and tube resonators
Slide 122
Slide 123
Helmholtz Resonator
Actions of a Helmholtz Resonator
Stephen M Tasko
Other Acoustic Resonators Tube Resonators
bull Uniform tubes Factors that influence resonancendash Lengthndash Cross-sectional area along its lengthndash Whether it is closed at either or both ends
Uniform tube closed at one end
Uniform tube closed at one end
Stephen M Tasko
Uniform tube closed at one end
First resonance or formant
F1 = c4lWhere
c=speed of sound (35000 cmsec)l = length of the tube
males ~ 175 cmfemales ~ 14 cm
Higher resonantformant frequencies are odd multiples of F1
For examplebull F1 = (c4l )1
bull F2 = (c4l )3
bull F3 = (c4l )5
Comparing Helmholtz and tube resonators
Resonator Features
Sharply tuned Broadly tuned
Resonator Features
An example of the resonance characteristics of the human vocal tract
Frequency
Gain
SPPA 4030 Speech Science
Topic 1 The Speech Chain
The Speech Chain (Denes amp Pinson 1993)
What information is embedded in the speech signal
Branches of science employed to understand speech communication
Physical Quantities Review An Independent Learning Activity
Assignment 1
Topic 2 The Source-Filter Theory of Speech Production An Intr
Producing Speech
Source-Filter Theory of Speech Production
Vocal tract is a tube that can vary its shape
Source Filter Theory
Same Source Different Filter
Different Source Same Filters
Different Source Same Filters (Human)
Different Source Same Filters (Human) (2)
Different Source Same Filters (Human) (3)
Different Source Same Filters (Human) (4)
Different Source Same Filters (Non-Human)
Different Source Same Filters (Non-Human) (2)
Different Source Same Filters (Non-Human) If it quacks like a
Source Filter Theory Applied Alaryngeal Speech
Source-Filter Theory Applied Esophageal Insufflation Test
Source-Filter Theory Applied Tracheoesophageal (TE) Speech
Source Filter Theory Applied The Talkbox
Source-Filter Theory Applied The Talkbox
Topic 3 A Brief Review of Physical Acoustics
Spring Mass Model
What is sound
Sound-conducting media
Model of air molecule vibration (Time 1)
Model of air molecule vibration (Time 2)
Model of air molecule vibration (Time 3)
Model of air molecule vibration (Time 4)
Model of air molecule vibration (Time 5)
Model of air molecule vibration
Wave action of molecular motion
Amplitude waveform
Amplitude waveform (2)
Where is pressure in this model
Pressure waveform
Measuring Sound
Measuring Sound Signal Amplitude
Measuring Sound Signal Amplitude (2)
What units do we use to measure signal amplitude
Brief Review The decibel scale
Absolute vs relative measurement
Typical reference values
Howeverhellip
Linear vs logarithmic
Linear vs logarithmic (2)
Logarithmic Scale
Logarithmic Scale (2)
Combining the idea of logarithmic and relativehellip
Intensity vs Pressure
Extending the formula to pressure
Measuring Sound Frequencyperiod
Measuring Sound Frequencyperiod (2)
Phase Uniform Circular Motion
Initiating a sound waves that differ only in phase
Spatial variation in pressure wave
Spatial variation in pressure wave
Spatial variation in pressure wave (2)
Relation between frequency and wavelength
Learning Objectives
Graphic representation of sound
Same sound different graphs
Classification of sounds
Simple periodic sound
Simple periodic sound Graphic appearance
Complex periodic sounds
Complex periodic sounds Graphic appearance
Complex periodic sounds Graphic appearance (2)
Glottal Source
Amplitude vs Phase Spectrum
Amplitude vs Phase Spectrum (2)
(Complex) Aperiodic sounds
Aperiodic sounds Graphic appearance
Aperiodic sounds Graphic appearance (2)
Analysis of complex waves
Learning Objectives (2)
The ldquoenveloperdquo of a sound wave
Waveform envelope
Waveform envelope (2)
Spectrum envelope
Thought Question
Amplitude Spectrum Window Size
ldquoInstantaneousrdquo Amplitude Spectra
(Long Term) Average Amplitude Spectrum
Slide 90
Learning Objectives (3)
The Spectrogram
Building a spectrogram
Building a spectrogram
Building a spectrogram (2)
Two main types of spectrograms
Wide vs Narrow Band Spectrograms
Learning Objectives (4)
What is an ldquoAcousticrdquo Filter
Why might we be interested in filters
Kinds of frequency selective filters
Low Pass Filters
High Pass Filters
Band Pass Filter
Frequency Response Curve (FRC)
Operation of a filter on a signal
Learning Objectives (5)
Free vibration
Forced vibration
Forced vibration (2)
Resonance refers to
Back to the mass spring model
Acoustic Resonance
Acoustic Resonance (2)
Helmholtz Resonator
Actions of a Helmholtz Resonator
Other Acoustic Resonators Tube Resonators
Uniform tube closed at one end
Uniform tube closed at one end (2)
Uniform tube closed at one end
Comparing Helmholtz and tube resonators
Slide 122
Slide 123
Actions of a Helmholtz Resonator
Stephen M Tasko
Other Acoustic Resonators Tube Resonators
bull Uniform tubes Factors that influence resonancendash Lengthndash Cross-sectional area along its lengthndash Whether it is closed at either or both ends
Uniform tube closed at one end
Uniform tube closed at one end
Stephen M Tasko
Uniform tube closed at one end
First resonance or formant
F1 = c4lWhere
c=speed of sound (35000 cmsec)l = length of the tube
males ~ 175 cmfemales ~ 14 cm
Higher resonantformant frequencies are odd multiples of F1
For examplebull F1 = (c4l )1
bull F2 = (c4l )3
bull F3 = (c4l )5
Comparing Helmholtz and tube resonators
Resonator Features
Sharply tuned Broadly tuned
Resonator Features
An example of the resonance characteristics of the human vocal tract
Frequency
Gain
SPPA 4030 Speech Science
Topic 1 The Speech Chain
The Speech Chain (Denes amp Pinson 1993)
What information is embedded in the speech signal
Branches of science employed to understand speech communication
Physical Quantities Review An Independent Learning Activity
Assignment 1
Topic 2 The Source-Filter Theory of Speech Production An Intr
Producing Speech
Source-Filter Theory of Speech Production
Vocal tract is a tube that can vary its shape
Source Filter Theory
Same Source Different Filter
Different Source Same Filters
Different Source Same Filters (Human)
Different Source Same Filters (Human) (2)
Different Source Same Filters (Human) (3)
Different Source Same Filters (Human) (4)
Different Source Same Filters (Non-Human)
Different Source Same Filters (Non-Human) (2)
Different Source Same Filters (Non-Human) If it quacks like a
Source Filter Theory Applied Alaryngeal Speech
Source-Filter Theory Applied Esophageal Insufflation Test
Source-Filter Theory Applied Tracheoesophageal (TE) Speech
Source Filter Theory Applied The Talkbox
Source-Filter Theory Applied The Talkbox
Topic 3 A Brief Review of Physical Acoustics
Spring Mass Model
What is sound
Sound-conducting media
Model of air molecule vibration (Time 1)
Model of air molecule vibration (Time 2)
Model of air molecule vibration (Time 3)
Model of air molecule vibration (Time 4)
Model of air molecule vibration (Time 5)
Model of air molecule vibration
Wave action of molecular motion
Amplitude waveform
Amplitude waveform (2)
Where is pressure in this model
Pressure waveform
Measuring Sound
Measuring Sound Signal Amplitude
Measuring Sound Signal Amplitude (2)
What units do we use to measure signal amplitude
Brief Review The decibel scale
Absolute vs relative measurement
Typical reference values
Howeverhellip
Linear vs logarithmic
Linear vs logarithmic (2)
Logarithmic Scale
Logarithmic Scale (2)
Combining the idea of logarithmic and relativehellip
Intensity vs Pressure
Extending the formula to pressure
Measuring Sound Frequencyperiod
Measuring Sound Frequencyperiod (2)
Phase Uniform Circular Motion
Initiating a sound waves that differ only in phase
Spatial variation in pressure wave
Spatial variation in pressure wave
Spatial variation in pressure wave (2)
Relation between frequency and wavelength
Learning Objectives
Graphic representation of sound
Same sound different graphs
Classification of sounds
Simple periodic sound
Simple periodic sound Graphic appearance
Complex periodic sounds
Complex periodic sounds Graphic appearance
Complex periodic sounds Graphic appearance (2)
Glottal Source
Amplitude vs Phase Spectrum
Amplitude vs Phase Spectrum (2)
(Complex) Aperiodic sounds
Aperiodic sounds Graphic appearance
Aperiodic sounds Graphic appearance (2)
Analysis of complex waves
Learning Objectives (2)
The ldquoenveloperdquo of a sound wave
Waveform envelope
Waveform envelope (2)
Spectrum envelope
Thought Question
Amplitude Spectrum Window Size
ldquoInstantaneousrdquo Amplitude Spectra
(Long Term) Average Amplitude Spectrum
Slide 90
Learning Objectives (3)
The Spectrogram
Building a spectrogram
Building a spectrogram
Building a spectrogram (2)
Two main types of spectrograms
Wide vs Narrow Band Spectrograms
Learning Objectives (4)
What is an ldquoAcousticrdquo Filter
Why might we be interested in filters
Kinds of frequency selective filters
Low Pass Filters
High Pass Filters
Band Pass Filter
Frequency Response Curve (FRC)
Operation of a filter on a signal
Learning Objectives (5)
Free vibration
Forced vibration
Forced vibration (2)
Resonance refers to
Back to the mass spring model
Acoustic Resonance
Acoustic Resonance (2)
Helmholtz Resonator
Actions of a Helmholtz Resonator
Other Acoustic Resonators Tube Resonators
Uniform tube closed at one end
Uniform tube closed at one end (2)
Uniform tube closed at one end
Comparing Helmholtz and tube resonators
Slide 122
Slide 123
Stephen M Tasko
Other Acoustic Resonators Tube Resonators
bull Uniform tubes Factors that influence resonancendash Lengthndash Cross-sectional area along its lengthndash Whether it is closed at either or both ends
Uniform tube closed at one end
Uniform tube closed at one end
Stephen M Tasko
Uniform tube closed at one end
First resonance or formant
F1 = c4lWhere
c=speed of sound (35000 cmsec)l = length of the tube
males ~ 175 cmfemales ~ 14 cm
Higher resonantformant frequencies are odd multiples of F1
For examplebull F1 = (c4l )1
bull F2 = (c4l )3
bull F3 = (c4l )5
Comparing Helmholtz and tube resonators
Resonator Features
Sharply tuned Broadly tuned
Resonator Features
An example of the resonance characteristics of the human vocal tract
Frequency
Gain
SPPA 4030 Speech Science
Topic 1 The Speech Chain
The Speech Chain (Denes amp Pinson 1993)
What information is embedded in the speech signal
Branches of science employed to understand speech communication
Physical Quantities Review An Independent Learning Activity
Assignment 1
Topic 2 The Source-Filter Theory of Speech Production An Intr
Producing Speech
Source-Filter Theory of Speech Production
Vocal tract is a tube that can vary its shape
Source Filter Theory
Same Source Different Filter
Different Source Same Filters
Different Source Same Filters (Human)
Different Source Same Filters (Human) (2)
Different Source Same Filters (Human) (3)
Different Source Same Filters (Human) (4)
Different Source Same Filters (Non-Human)
Different Source Same Filters (Non-Human) (2)
Different Source Same Filters (Non-Human) If it quacks like a
Source Filter Theory Applied Alaryngeal Speech
Source-Filter Theory Applied Esophageal Insufflation Test
Source-Filter Theory Applied Tracheoesophageal (TE) Speech
Source Filter Theory Applied The Talkbox
Source-Filter Theory Applied The Talkbox
Topic 3 A Brief Review of Physical Acoustics
Spring Mass Model
What is sound
Sound-conducting media
Model of air molecule vibration (Time 1)
Model of air molecule vibration (Time 2)
Model of air molecule vibration (Time 3)
Model of air molecule vibration (Time 4)
Model of air molecule vibration (Time 5)
Model of air molecule vibration
Wave action of molecular motion
Amplitude waveform
Amplitude waveform (2)
Where is pressure in this model
Pressure waveform
Measuring Sound
Measuring Sound Signal Amplitude
Measuring Sound Signal Amplitude (2)
What units do we use to measure signal amplitude
Brief Review The decibel scale
Absolute vs relative measurement
Typical reference values
Howeverhellip
Linear vs logarithmic
Linear vs logarithmic (2)
Logarithmic Scale
Logarithmic Scale (2)
Combining the idea of logarithmic and relativehellip
Intensity vs Pressure
Extending the formula to pressure
Measuring Sound Frequencyperiod
Measuring Sound Frequencyperiod (2)
Phase Uniform Circular Motion
Initiating a sound waves that differ only in phase
Spatial variation in pressure wave
Spatial variation in pressure wave
Spatial variation in pressure wave (2)
Relation between frequency and wavelength
Learning Objectives
Graphic representation of sound
Same sound different graphs
Classification of sounds
Simple periodic sound
Simple periodic sound Graphic appearance
Complex periodic sounds
Complex periodic sounds Graphic appearance
Complex periodic sounds Graphic appearance (2)
Glottal Source
Amplitude vs Phase Spectrum
Amplitude vs Phase Spectrum (2)
(Complex) Aperiodic sounds
Aperiodic sounds Graphic appearance
Aperiodic sounds Graphic appearance (2)
Analysis of complex waves
Learning Objectives (2)
The ldquoenveloperdquo of a sound wave
Waveform envelope
Waveform envelope (2)
Spectrum envelope
Thought Question
Amplitude Spectrum Window Size
ldquoInstantaneousrdquo Amplitude Spectra
(Long Term) Average Amplitude Spectrum
Slide 90
Learning Objectives (3)
The Spectrogram
Building a spectrogram
Building a spectrogram
Building a spectrogram (2)
Two main types of spectrograms
Wide vs Narrow Band Spectrograms
Learning Objectives (4)
What is an ldquoAcousticrdquo Filter
Why might we be interested in filters
Kinds of frequency selective filters
Low Pass Filters
High Pass Filters
Band Pass Filter
Frequency Response Curve (FRC)
Operation of a filter on a signal
Learning Objectives (5)
Free vibration
Forced vibration
Forced vibration (2)
Resonance refers to
Back to the mass spring model
Acoustic Resonance
Acoustic Resonance (2)
Helmholtz Resonator
Actions of a Helmholtz Resonator
Other Acoustic Resonators Tube Resonators
Uniform tube closed at one end
Uniform tube closed at one end (2)
Uniform tube closed at one end
Comparing Helmholtz and tube resonators
Slide 122
Slide 123
Uniform tube closed at one end
Uniform tube closed at one end
Stephen M Tasko
Uniform tube closed at one end
First resonance or formant
F1 = c4lWhere
c=speed of sound (35000 cmsec)l = length of the tube
males ~ 175 cmfemales ~ 14 cm
Higher resonantformant frequencies are odd multiples of F1
For examplebull F1 = (c4l )1
bull F2 = (c4l )3
bull F3 = (c4l )5
Comparing Helmholtz and tube resonators
Resonator Features
Sharply tuned Broadly tuned
Resonator Features
An example of the resonance characteristics of the human vocal tract
Frequency
Gain
SPPA 4030 Speech Science
Topic 1 The Speech Chain
The Speech Chain (Denes amp Pinson 1993)
What information is embedded in the speech signal
Branches of science employed to understand speech communication
Physical Quantities Review An Independent Learning Activity
Assignment 1
Topic 2 The Source-Filter Theory of Speech Production An Intr
Producing Speech
Source-Filter Theory of Speech Production
Vocal tract is a tube that can vary its shape
Source Filter Theory
Same Source Different Filter
Different Source Same Filters
Different Source Same Filters (Human)
Different Source Same Filters (Human) (2)
Different Source Same Filters (Human) (3)
Different Source Same Filters (Human) (4)
Different Source Same Filters (Non-Human)
Different Source Same Filters (Non-Human) (2)
Different Source Same Filters (Non-Human) If it quacks like a
Source Filter Theory Applied Alaryngeal Speech
Source-Filter Theory Applied Esophageal Insufflation Test
Source-Filter Theory Applied Tracheoesophageal (TE) Speech
Source Filter Theory Applied The Talkbox
Source-Filter Theory Applied The Talkbox
Topic 3 A Brief Review of Physical Acoustics
Spring Mass Model
What is sound
Sound-conducting media
Model of air molecule vibration (Time 1)
Model of air molecule vibration (Time 2)
Model of air molecule vibration (Time 3)
Model of air molecule vibration (Time 4)
Model of air molecule vibration (Time 5)
Model of air molecule vibration
Wave action of molecular motion
Amplitude waveform
Amplitude waveform (2)
Where is pressure in this model
Pressure waveform
Measuring Sound
Measuring Sound Signal Amplitude
Measuring Sound Signal Amplitude (2)
What units do we use to measure signal amplitude
Brief Review The decibel scale
Absolute vs relative measurement
Typical reference values
Howeverhellip
Linear vs logarithmic
Linear vs logarithmic (2)
Logarithmic Scale
Logarithmic Scale (2)
Combining the idea of logarithmic and relativehellip
Intensity vs Pressure
Extending the formula to pressure
Measuring Sound Frequencyperiod
Measuring Sound Frequencyperiod (2)
Phase Uniform Circular Motion
Initiating a sound waves that differ only in phase
Spatial variation in pressure wave
Spatial variation in pressure wave
Spatial variation in pressure wave (2)
Relation between frequency and wavelength
Learning Objectives
Graphic representation of sound
Same sound different graphs
Classification of sounds
Simple periodic sound
Simple periodic sound Graphic appearance
Complex periodic sounds
Complex periodic sounds Graphic appearance
Complex periodic sounds Graphic appearance (2)
Glottal Source
Amplitude vs Phase Spectrum
Amplitude vs Phase Spectrum (2)
(Complex) Aperiodic sounds
Aperiodic sounds Graphic appearance
Aperiodic sounds Graphic appearance (2)
Analysis of complex waves
Learning Objectives (2)
The ldquoenveloperdquo of a sound wave
Waveform envelope
Waveform envelope (2)
Spectrum envelope
Thought Question
Amplitude Spectrum Window Size
ldquoInstantaneousrdquo Amplitude Spectra
(Long Term) Average Amplitude Spectrum
Slide 90
Learning Objectives (3)
The Spectrogram
Building a spectrogram
Building a spectrogram
Building a spectrogram (2)
Two main types of spectrograms
Wide vs Narrow Band Spectrograms
Learning Objectives (4)
What is an ldquoAcousticrdquo Filter
Why might we be interested in filters
Kinds of frequency selective filters
Low Pass Filters
High Pass Filters
Band Pass Filter
Frequency Response Curve (FRC)
Operation of a filter on a signal
Learning Objectives (5)
Free vibration
Forced vibration
Forced vibration (2)
Resonance refers to
Back to the mass spring model
Acoustic Resonance
Acoustic Resonance (2)
Helmholtz Resonator
Actions of a Helmholtz Resonator
Other Acoustic Resonators Tube Resonators
Uniform tube closed at one end
Uniform tube closed at one end (2)
Uniform tube closed at one end
Comparing Helmholtz and tube resonators
Slide 122
Slide 123
Uniform tube closed at one end
Stephen M Tasko
Uniform tube closed at one end
First resonance or formant
F1 = c4lWhere
c=speed of sound (35000 cmsec)l = length of the tube
males ~ 175 cmfemales ~ 14 cm
Higher resonantformant frequencies are odd multiples of F1
For examplebull F1 = (c4l )1
bull F2 = (c4l )3
bull F3 = (c4l )5
Comparing Helmholtz and tube resonators
Resonator Features
Sharply tuned Broadly tuned
Resonator Features
An example of the resonance characteristics of the human vocal tract
Frequency
Gain
SPPA 4030 Speech Science
Topic 1 The Speech Chain
The Speech Chain (Denes amp Pinson 1993)
What information is embedded in the speech signal
Branches of science employed to understand speech communication
Physical Quantities Review An Independent Learning Activity
Assignment 1
Topic 2 The Source-Filter Theory of Speech Production An Intr
Producing Speech
Source-Filter Theory of Speech Production
Vocal tract is a tube that can vary its shape
Source Filter Theory
Same Source Different Filter
Different Source Same Filters
Different Source Same Filters (Human)
Different Source Same Filters (Human) (2)
Different Source Same Filters (Human) (3)
Different Source Same Filters (Human) (4)
Different Source Same Filters (Non-Human)
Different Source Same Filters (Non-Human) (2)
Different Source Same Filters (Non-Human) If it quacks like a
Source Filter Theory Applied Alaryngeal Speech
Source-Filter Theory Applied Esophageal Insufflation Test
Source-Filter Theory Applied Tracheoesophageal (TE) Speech
Source Filter Theory Applied The Talkbox
Source-Filter Theory Applied The Talkbox
Topic 3 A Brief Review of Physical Acoustics
Spring Mass Model
What is sound
Sound-conducting media
Model of air molecule vibration (Time 1)
Model of air molecule vibration (Time 2)
Model of air molecule vibration (Time 3)
Model of air molecule vibration (Time 4)
Model of air molecule vibration (Time 5)
Model of air molecule vibration
Wave action of molecular motion
Amplitude waveform
Amplitude waveform (2)
Where is pressure in this model
Pressure waveform
Measuring Sound
Measuring Sound Signal Amplitude
Measuring Sound Signal Amplitude (2)
What units do we use to measure signal amplitude
Brief Review The decibel scale
Absolute vs relative measurement
Typical reference values
Howeverhellip
Linear vs logarithmic
Linear vs logarithmic (2)
Logarithmic Scale
Logarithmic Scale (2)
Combining the idea of logarithmic and relativehellip
Intensity vs Pressure
Extending the formula to pressure
Measuring Sound Frequencyperiod
Measuring Sound Frequencyperiod (2)
Phase Uniform Circular Motion
Initiating a sound waves that differ only in phase
Spatial variation in pressure wave
Spatial variation in pressure wave
Spatial variation in pressure wave (2)
Relation between frequency and wavelength
Learning Objectives
Graphic representation of sound
Same sound different graphs
Classification of sounds
Simple periodic sound
Simple periodic sound Graphic appearance
Complex periodic sounds
Complex periodic sounds Graphic appearance
Complex periodic sounds Graphic appearance (2)
Glottal Source
Amplitude vs Phase Spectrum
Amplitude vs Phase Spectrum (2)
(Complex) Aperiodic sounds
Aperiodic sounds Graphic appearance
Aperiodic sounds Graphic appearance (2)
Analysis of complex waves
Learning Objectives (2)
The ldquoenveloperdquo of a sound wave
Waveform envelope
Waveform envelope (2)
Spectrum envelope
Thought Question
Amplitude Spectrum Window Size
ldquoInstantaneousrdquo Amplitude Spectra
(Long Term) Average Amplitude Spectrum
Slide 90
Learning Objectives (3)
The Spectrogram
Building a spectrogram
Building a spectrogram
Building a spectrogram (2)
Two main types of spectrograms
Wide vs Narrow Band Spectrograms
Learning Objectives (4)
What is an ldquoAcousticrdquo Filter
Why might we be interested in filters
Kinds of frequency selective filters
Low Pass Filters
High Pass Filters
Band Pass Filter
Frequency Response Curve (FRC)
Operation of a filter on a signal
Learning Objectives (5)
Free vibration
Forced vibration
Forced vibration (2)
Resonance refers to
Back to the mass spring model
Acoustic Resonance
Acoustic Resonance (2)
Helmholtz Resonator
Actions of a Helmholtz Resonator
Other Acoustic Resonators Tube Resonators
Uniform tube closed at one end
Uniform tube closed at one end (2)
Uniform tube closed at one end
Comparing Helmholtz and tube resonators
Slide 122
Slide 123
Stephen M Tasko
Uniform tube closed at one end
First resonance or formant
F1 = c4lWhere
c=speed of sound (35000 cmsec)l = length of the tube
males ~ 175 cmfemales ~ 14 cm
Higher resonantformant frequencies are odd multiples of F1
For examplebull F1 = (c4l )1
bull F2 = (c4l )3
bull F3 = (c4l )5
Comparing Helmholtz and tube resonators
Resonator Features
Sharply tuned Broadly tuned
Resonator Features
An example of the resonance characteristics of the human vocal tract
Frequency
Gain
SPPA 4030 Speech Science
Topic 1 The Speech Chain
The Speech Chain (Denes amp Pinson 1993)
What information is embedded in the speech signal
Branches of science employed to understand speech communication
Physical Quantities Review An Independent Learning Activity
Assignment 1
Topic 2 The Source-Filter Theory of Speech Production An Intr
Producing Speech
Source-Filter Theory of Speech Production
Vocal tract is a tube that can vary its shape
Source Filter Theory
Same Source Different Filter
Different Source Same Filters
Different Source Same Filters (Human)
Different Source Same Filters (Human) (2)
Different Source Same Filters (Human) (3)
Different Source Same Filters (Human) (4)
Different Source Same Filters (Non-Human)
Different Source Same Filters (Non-Human) (2)
Different Source Same Filters (Non-Human) If it quacks like a
Source Filter Theory Applied Alaryngeal Speech
Source-Filter Theory Applied Esophageal Insufflation Test
Source-Filter Theory Applied Tracheoesophageal (TE) Speech
Source Filter Theory Applied The Talkbox
Source-Filter Theory Applied The Talkbox
Topic 3 A Brief Review of Physical Acoustics
Spring Mass Model
What is sound
Sound-conducting media
Model of air molecule vibration (Time 1)
Model of air molecule vibration (Time 2)
Model of air molecule vibration (Time 3)
Model of air molecule vibration (Time 4)
Model of air molecule vibration (Time 5)
Model of air molecule vibration
Wave action of molecular motion
Amplitude waveform
Amplitude waveform (2)
Where is pressure in this model
Pressure waveform
Measuring Sound
Measuring Sound Signal Amplitude
Measuring Sound Signal Amplitude (2)
What units do we use to measure signal amplitude
Brief Review The decibel scale
Absolute vs relative measurement
Typical reference values
Howeverhellip
Linear vs logarithmic
Linear vs logarithmic (2)
Logarithmic Scale
Logarithmic Scale (2)
Combining the idea of logarithmic and relativehellip
Intensity vs Pressure
Extending the formula to pressure
Measuring Sound Frequencyperiod
Measuring Sound Frequencyperiod (2)
Phase Uniform Circular Motion
Initiating a sound waves that differ only in phase
Spatial variation in pressure wave
Spatial variation in pressure wave
Spatial variation in pressure wave (2)
Relation between frequency and wavelength
Learning Objectives
Graphic representation of sound
Same sound different graphs
Classification of sounds
Simple periodic sound
Simple periodic sound Graphic appearance
Complex periodic sounds
Complex periodic sounds Graphic appearance
Complex periodic sounds Graphic appearance (2)
Glottal Source
Amplitude vs Phase Spectrum
Amplitude vs Phase Spectrum (2)
(Complex) Aperiodic sounds
Aperiodic sounds Graphic appearance
Aperiodic sounds Graphic appearance (2)
Analysis of complex waves
Learning Objectives (2)
The ldquoenveloperdquo of a sound wave
Waveform envelope
Waveform envelope (2)
Spectrum envelope
Thought Question
Amplitude Spectrum Window Size
ldquoInstantaneousrdquo Amplitude Spectra
(Long Term) Average Amplitude Spectrum
Slide 90
Learning Objectives (3)
The Spectrogram
Building a spectrogram
Building a spectrogram
Building a spectrogram (2)
Two main types of spectrograms
Wide vs Narrow Band Spectrograms
Learning Objectives (4)
What is an ldquoAcousticrdquo Filter
Why might we be interested in filters
Kinds of frequency selective filters
Low Pass Filters
High Pass Filters
Band Pass Filter
Frequency Response Curve (FRC)
Operation of a filter on a signal
Learning Objectives (5)
Free vibration
Forced vibration
Forced vibration (2)
Resonance refers to
Back to the mass spring model
Acoustic Resonance
Acoustic Resonance (2)
Helmholtz Resonator
Actions of a Helmholtz Resonator
Other Acoustic Resonators Tube Resonators
Uniform tube closed at one end
Uniform tube closed at one end (2)
Uniform tube closed at one end
Comparing Helmholtz and tube resonators
Slide 122
Slide 123
Comparing Helmholtz and tube resonators
Resonator Features
Sharply tuned Broadly tuned
Resonator Features
An example of the resonance characteristics of the human vocal tract
Frequency
Gain
SPPA 4030 Speech Science
Topic 1 The Speech Chain
The Speech Chain (Denes amp Pinson 1993)
What information is embedded in the speech signal
Branches of science employed to understand speech communication
Physical Quantities Review An Independent Learning Activity
Assignment 1
Topic 2 The Source-Filter Theory of Speech Production An Intr
Producing Speech
Source-Filter Theory of Speech Production
Vocal tract is a tube that can vary its shape
Source Filter Theory
Same Source Different Filter
Different Source Same Filters
Different Source Same Filters (Human)
Different Source Same Filters (Human) (2)
Different Source Same Filters (Human) (3)
Different Source Same Filters (Human) (4)
Different Source Same Filters (Non-Human)
Different Source Same Filters (Non-Human) (2)
Different Source Same Filters (Non-Human) If it quacks like a
Source Filter Theory Applied Alaryngeal Speech
Source-Filter Theory Applied Esophageal Insufflation Test
Source-Filter Theory Applied Tracheoesophageal (TE) Speech
Source Filter Theory Applied The Talkbox
Source-Filter Theory Applied The Talkbox
Topic 3 A Brief Review of Physical Acoustics
Spring Mass Model
What is sound
Sound-conducting media
Model of air molecule vibration (Time 1)
Model of air molecule vibration (Time 2)
Model of air molecule vibration (Time 3)
Model of air molecule vibration (Time 4)
Model of air molecule vibration (Time 5)
Model of air molecule vibration
Wave action of molecular motion
Amplitude waveform
Amplitude waveform (2)
Where is pressure in this model
Pressure waveform
Measuring Sound
Measuring Sound Signal Amplitude
Measuring Sound Signal Amplitude (2)
What units do we use to measure signal amplitude
Brief Review The decibel scale
Absolute vs relative measurement
Typical reference values
Howeverhellip
Linear vs logarithmic
Linear vs logarithmic (2)
Logarithmic Scale
Logarithmic Scale (2)
Combining the idea of logarithmic and relativehellip
Intensity vs Pressure
Extending the formula to pressure
Measuring Sound Frequencyperiod
Measuring Sound Frequencyperiod (2)
Phase Uniform Circular Motion
Initiating a sound waves that differ only in phase
Spatial variation in pressure wave
Spatial variation in pressure wave
Spatial variation in pressure wave (2)
Relation between frequency and wavelength
Learning Objectives
Graphic representation of sound
Same sound different graphs
Classification of sounds
Simple periodic sound
Simple periodic sound Graphic appearance
Complex periodic sounds
Complex periodic sounds Graphic appearance
Complex periodic sounds Graphic appearance (2)
Glottal Source
Amplitude vs Phase Spectrum
Amplitude vs Phase Spectrum (2)
(Complex) Aperiodic sounds
Aperiodic sounds Graphic appearance
Aperiodic sounds Graphic appearance (2)
Analysis of complex waves
Learning Objectives (2)
The ldquoenveloperdquo of a sound wave
Waveform envelope
Waveform envelope (2)
Spectrum envelope
Thought Question
Amplitude Spectrum Window Size
ldquoInstantaneousrdquo Amplitude Spectra
(Long Term) Average Amplitude Spectrum
Slide 90
Learning Objectives (3)
The Spectrogram
Building a spectrogram
Building a spectrogram
Building a spectrogram (2)
Two main types of spectrograms
Wide vs Narrow Band Spectrograms
Learning Objectives (4)
What is an ldquoAcousticrdquo Filter
Why might we be interested in filters
Kinds of frequency selective filters
Low Pass Filters
High Pass Filters
Band Pass Filter
Frequency Response Curve (FRC)
Operation of a filter on a signal
Learning Objectives (5)
Free vibration
Forced vibration
Forced vibration (2)
Resonance refers to
Back to the mass spring model
Acoustic Resonance
Acoustic Resonance (2)
Helmholtz Resonator
Actions of a Helmholtz Resonator
Other Acoustic Resonators Tube Resonators
Uniform tube closed at one end
Uniform tube closed at one end (2)
Uniform tube closed at one end
Comparing Helmholtz and tube resonators
Slide 122
Slide 123
Resonator Features
Sharply tuned Broadly tuned
Resonator Features
An example of the resonance characteristics of the human vocal tract
Frequency
Gain
SPPA 4030 Speech Science
Topic 1 The Speech Chain
The Speech Chain (Denes amp Pinson 1993)
What information is embedded in the speech signal
Branches of science employed to understand speech communication
Physical Quantities Review An Independent Learning Activity
Assignment 1
Topic 2 The Source-Filter Theory of Speech Production An Intr
Producing Speech
Source-Filter Theory of Speech Production
Vocal tract is a tube that can vary its shape
Source Filter Theory
Same Source Different Filter
Different Source Same Filters
Different Source Same Filters (Human)
Different Source Same Filters (Human) (2)
Different Source Same Filters (Human) (3)
Different Source Same Filters (Human) (4)
Different Source Same Filters (Non-Human)
Different Source Same Filters (Non-Human) (2)
Different Source Same Filters (Non-Human) If it quacks like a
Source Filter Theory Applied Alaryngeal Speech
Source-Filter Theory Applied Esophageal Insufflation Test
Source-Filter Theory Applied Tracheoesophageal (TE) Speech
Source Filter Theory Applied The Talkbox
Source-Filter Theory Applied The Talkbox
Topic 3 A Brief Review of Physical Acoustics
Spring Mass Model
What is sound
Sound-conducting media
Model of air molecule vibration (Time 1)
Model of air molecule vibration (Time 2)
Model of air molecule vibration (Time 3)
Model of air molecule vibration (Time 4)
Model of air molecule vibration (Time 5)
Model of air molecule vibration
Wave action of molecular motion
Amplitude waveform
Amplitude waveform (2)
Where is pressure in this model
Pressure waveform
Measuring Sound
Measuring Sound Signal Amplitude
Measuring Sound Signal Amplitude (2)
What units do we use to measure signal amplitude
Brief Review The decibel scale
Absolute vs relative measurement
Typical reference values
Howeverhellip
Linear vs logarithmic
Linear vs logarithmic (2)
Logarithmic Scale
Logarithmic Scale (2)
Combining the idea of logarithmic and relativehellip
Intensity vs Pressure
Extending the formula to pressure
Measuring Sound Frequencyperiod
Measuring Sound Frequencyperiod (2)
Phase Uniform Circular Motion
Initiating a sound waves that differ only in phase
Spatial variation in pressure wave
Spatial variation in pressure wave
Spatial variation in pressure wave (2)
Relation between frequency and wavelength
Learning Objectives
Graphic representation of sound
Same sound different graphs
Classification of sounds
Simple periodic sound
Simple periodic sound Graphic appearance
Complex periodic sounds
Complex periodic sounds Graphic appearance
Complex periodic sounds Graphic appearance (2)
Glottal Source
Amplitude vs Phase Spectrum
Amplitude vs Phase Spectrum (2)
(Complex) Aperiodic sounds
Aperiodic sounds Graphic appearance
Aperiodic sounds Graphic appearance (2)
Analysis of complex waves
Learning Objectives (2)
The ldquoenveloperdquo of a sound wave
Waveform envelope
Waveform envelope (2)
Spectrum envelope
Thought Question
Amplitude Spectrum Window Size
ldquoInstantaneousrdquo Amplitude Spectra
(Long Term) Average Amplitude Spectrum
Slide 90
Learning Objectives (3)
The Spectrogram
Building a spectrogram
Building a spectrogram
Building a spectrogram (2)
Two main types of spectrograms
Wide vs Narrow Band Spectrograms
Learning Objectives (4)
What is an ldquoAcousticrdquo Filter
Why might we be interested in filters
Kinds of frequency selective filters
Low Pass Filters
High Pass Filters
Band Pass Filter
Frequency Response Curve (FRC)
Operation of a filter on a signal
Learning Objectives (5)
Free vibration
Forced vibration
Forced vibration (2)
Resonance refers to
Back to the mass spring model
Acoustic Resonance
Acoustic Resonance (2)
Helmholtz Resonator
Actions of a Helmholtz Resonator
Other Acoustic Resonators Tube Resonators
Uniform tube closed at one end
Uniform tube closed at one end (2)
Uniform tube closed at one end
Comparing Helmholtz and tube resonators
Slide 122
Slide 123
Resonator Features
An example of the resonance characteristics of the human vocal tract
Frequency
Gain
SPPA 4030 Speech Science
Topic 1 The Speech Chain
The Speech Chain (Denes amp Pinson 1993)
What information is embedded in the speech signal
Branches of science employed to understand speech communication
Physical Quantities Review An Independent Learning Activity
Assignment 1
Topic 2 The Source-Filter Theory of Speech Production An Intr
Producing Speech
Source-Filter Theory of Speech Production
Vocal tract is a tube that can vary its shape
Source Filter Theory
Same Source Different Filter
Different Source Same Filters
Different Source Same Filters (Human)
Different Source Same Filters (Human) (2)
Different Source Same Filters (Human) (3)
Different Source Same Filters (Human) (4)
Different Source Same Filters (Non-Human)
Different Source Same Filters (Non-Human) (2)
Different Source Same Filters (Non-Human) If it quacks like a
Source Filter Theory Applied Alaryngeal Speech
Source-Filter Theory Applied Esophageal Insufflation Test
Source-Filter Theory Applied Tracheoesophageal (TE) Speech
Source Filter Theory Applied The Talkbox
Source-Filter Theory Applied The Talkbox
Topic 3 A Brief Review of Physical Acoustics
Spring Mass Model
What is sound
Sound-conducting media
Model of air molecule vibration (Time 1)
Model of air molecule vibration (Time 2)
Model of air molecule vibration (Time 3)
Model of air molecule vibration (Time 4)
Model of air molecule vibration (Time 5)
Model of air molecule vibration
Wave action of molecular motion
Amplitude waveform
Amplitude waveform (2)
Where is pressure in this model
Pressure waveform
Measuring Sound
Measuring Sound Signal Amplitude
Measuring Sound Signal Amplitude (2)
What units do we use to measure signal amplitude
Brief Review The decibel scale
Absolute vs relative measurement
Typical reference values
Howeverhellip
Linear vs logarithmic
Linear vs logarithmic (2)
Logarithmic Scale
Logarithmic Scale (2)
Combining the idea of logarithmic and relativehellip
Intensity vs Pressure
Extending the formula to pressure
Measuring Sound Frequencyperiod
Measuring Sound Frequencyperiod (2)
Phase Uniform Circular Motion
Initiating a sound waves that differ only in phase
