Download - Frequency-Place-Transformation
Frequency-Place Transformation AIPA: Models of Auditory Perception Seminar
20 November 2014
The speaker
Francesco Bonadiman [email protected]
Computer Science
Bachelor @UniTN (Trento, IT)
2/29
The speaker
Francesco Bonadiman [email protected]
Computer Science
Bachelor @UniTN (Trento, IT)
2/29
The speaker
Francesco Bonadiman [email protected]
Computer Science
Bachelor @UniTN (Trento, IT)
2/29
The outer ear
3/29
The outer ear
3/29
[Raake2014]
The outer ear
3/29
[Raake2014]
catalyzes the sound
The outer ear
3/29
[Raake2014]
catalyzes the sound
The middle ear
[Raake2014]
4/29
The middle ear
[Raake2014]
4/29
The middle ear
[Raake2014]
3 smallest bones in the body
4/29
[Blausen2014] 5/29
2 membrane- covered openings
[Blausen2014] 5/29
2 membrane- covered openings
[Blausen2014] 5/29
2 membrane- covered openings
[Blausen2014] 5/29
2 membrane- covered openings
[Blausen2014] 5/29
2 membrane- covered openings
opposite directions
How it works [Kidsdiscover2014]
6/29
How it works [Kidsdiscover2014]
6/29
difference of sound pressure
How it works [Kidsdiscover2014]
acoustic energy (air) → fluid oscillations
6/29
difference of sound pressure
How it works [Kidsdiscover2014]
impedance matching
acoustic energy (air) → fluid oscillations
6/29
difference of sound pressure
The inner ear
[Amplifon2014] 7/29
The inner ear
[Amplifon2014] 7/29
The inner ear
[Amplifon2014] 7/29
The cochlea: traditional view
8/29
The cochlea: traditional view
[Zwicker,Fastl2007] 8/29
The cochlea: traditional view
[Zwicker,Fastl2007] 8/29
The cochlea
[Wierstorf2014] 9/29
The cochlea
[Wierstorf2014] 9/29
2½ turns for saving space
The cochlea
[Wierstorf2014]
[RobinsonLibrary2014]
9/29
2½ turns for saving space
32 mm “unwound”
The cochlea
[Wierstorf2014]
[RobinsonLibrary2014]
[Wikipedia2014] 9/29
2½ turns for saving space
32 mm “unwound”
The cochlea
[Wierstorf2014]
[RobinsonLibrary2014]
[Wikipedia2014] 9/29
2½ turns for saving space
32 mm “unwound”
The cochlea
[Wierstorf2014]
[RobinsonLibrary2014]
[Wikipedia2014]
helicotrema 9/29
2½ turns for saving space
32 mm “unwound”
Channels and membranes
[Flanagan1972] 10/29
Channels and membranes
[Flanagan1972] 10/29
Channels and membranes
[Flanagan1972] 10/29
hydromechanically → single unit
Channels and membranes
[Flanagan1972] 10/29
Channels and membranes
[Flanagan1972] 10/29
fluids = oscillations
Overview [WhatWhenHow2014]
11/29
Overview [WhatWhenHow2014]
11/29
O H R
Overview [WhatWhenHow2014]
11/29
O H R
Is this enough?
12/29
Organ of Corti
[MixBag2014]
13/29
Organ of Corti
[MixBag2014]
13/29
Organ of Corti
[MixBag2014]
13/29
membranes excitation → nervous impulses (firings)
Organ of Corti
[MixBag2014] [Zwicker,Fastl2007]
13/29
membranes excitation → nervous impulses (firings)
Organ of Corti
[MixBag2014] [Zwicker,Fastl2007]
13/29
membranes excitation → nervous impulses (firings)
Organ of Corti
[MixBag2014] [Zwicker,Fastl2007]
13/29
IHC → brain OHC → tuning
membranes excitation → nervous impulses (firings)
14/29 [GalleryHip2014]
14/29
membranes shearing → HC-cilia → nerve fibers
[GalleryHip2014]
15/29
Frequency-Place-Transformation
[Mandel, Ellis2009] 16/29
Frequency-Place-Transformation
[Mandel, Ellis2009] 16/29
Frequency-Place-Transformation
[Mandel, Ellis2009] 16/29
Frequency-Place-Transformation
[Mandel, Ellis2009] 16/29
BM = kind of Fourier Analysis
Waves and peaks
[Moore2013] 17/29
Waves and peaks
[Moore2013] 17/29
Waves and peaks
[Moore2013] 17/29
Waves and peaks
[Moore2013] 17/29
spatial envelope
Waves and peaks
[Moore2013] 17/29
place + growth ← frequency
spatial envelope
Waves and peaks
[Moore2013] 17/29
place + growth ← frequency
spatial envelope
Waves and peaks
[Moore2013] 17/29
place + growth ← frequency
spatial envelope
Waves and peaks
[Moore2013] 17/29
place + growth ← frequency
spatial envelope
Characteristic Frequencies
[Zwicker,Fastl2007] 18/29
Characteristic Frequencies
[Zwicker,Fastl2007] 18/29
BM’s maximum displacement
Characteristic Frequencies
[Zwicker,Fastl2007] 18/29
BM’s maximum displacement
Mechanical Reasons [Skidmore.edu2014]
19/29
Mechanical Reasons [Skidmore.edu2014]
19/29
stiff thick narrow < 0.1 mm
Mechanical Reasons [Skidmore.edu2014]
19/29
stiff thick narrow < 0.1 mm
flexible thinner wider ∼0.5 mm
Mechanical Reasons [Skidmore.edu2014]
19/29
stiff thick narrow < 0.1 mm
flexible thinner wider ∼0.5 mm
[Wikipedia2014]
Mechanical Reasons [Skidmore.edu2014]
[Wikipedia2014] 19/29
stiff thick narrow < 0.1 mm
flexible thinner wider ∼0.5 mm
Von Békésy (1947) Pioneering work Light microscope
Human cadaver ear
20/29
Masking
21/29 [Wikipedia2014]
Masking
21/29
shows the limits of frequency selectivity (FPT)
[Wikipedia2014]
Masking
21/29
shows the limits of frequency selectivity (FPT)
auditory system → not distinguish between frequencies
[Wikipedia2014]
Masking
21/29
shows the limits of frequency selectivity (FPT)
depends on both signal and masker
auditory system → not distinguish between frequencies
[Wikipedia2014]
Masking
21/29
Detailed talk about it
shows the limits of frequency selectivity (FPT)
depends on both signal and masker
auditory system → not distinguish between frequencies
[Wikipedia2014]
Fletcher Experiment
22/29 [Wikipedia2014]
Fletcher Experiment
22/29 [Wikipedia2014]
masker = 65 dB
masked = 40 dB
Fletcher Experiment
22/29 [Wikipedia2014]
masker = 65 dB
masked = 40 dB
NO!
Fletcher Experiment
22/29 [Wikipedia2014]
masker = 65 dB not masked = 55 dB
masked = 40 dB
NO!
Fletcher Experiment
22/29 [Wikipedia2014]
masker = 65 dB not masked = 55 dB
masked = 40 dB
NO! YES!
Fletcher Experiment
22/29 [Wikipedia2014]
masker = 65 dB not masked = 55 dB
masked = 40 dB
NO! YES!
detect the shape of the so-called
Auditory Filters
Auditory Filters (Critical Bandwidth) [AcousticLab.org2014]
[Wikipedia2014] 23/29
Auditory Filters (Critical Bandwidth) [AcousticLab.org2014]
[Wikipedia2014] 23/29
USUALLY: sounds located singularly
limited range of frequencies different center frequency
Auditory Filters (Critical Bandwidth) [AcousticLab.org2014]
[Wikipedia2014] 23/29
USUALLY: sounds located singularly
limited range of frequencies different center frequency
MASKING: single, broader maximum signal perceived as one same critical bandwidth
BM frequency selectivity = fail
Critical-band Rate Scale
[Zwicker,Fastl2007]
24/29
Critical-band Rate Scale
[Zwicker,Fastl2007]
24/29
new unit leading to critical-band rate scale
Critical-band Rate Scale
[Zwicker,Fastl2007]
24/29
boundaries of the critical bands
new unit leading to critical-band rate scale
Critical-band Rate Scale
[Zwicker,Fastl2007]
24/29
boundaries of the critical bands
new unit leading to critical-band rate scale
audible frequency range in 24 bands
Critical-band Rate Scale
[Zwicker,Fastl2007]
25/29
Critical-band Rate Scale
[Zwicker,Fastl2007]
25/29
from 0 to 24 unit = Bark
(linear)
Critical-band Rate Scale
[Zwicker,Fastl2007]
25/29
higher frequency = bigger amplitude = broader filters from 0 to 24
unit = Bark (linear)
Critical-band Rate Scale
[Zwicker,Fastl2007]
25/29
higher frequency = bigger amplitude = broader filters
mechanical reasons of the membrane
(rigid = high frequencies)
from 0 to 24 unit = Bark
(linear)
Back to the Cochlea
[Zwicker,Fastl2007]
26/29
Back to the Cochlea
[Zwicker,Fastl2007]
26/29
GOLDEN RULE: FPT → Inside our ear, frequencies are mapped onto certain locations
Back to the Cochlea
[Zwicker,Fastl2007]
26/29
SILVER RULE: Mapping not linear but ∼linear up to 500 Hz ∼logarithmic above
GOLDEN RULE: FPT → Inside our ear, frequencies are mapped onto certain locations
27/29
28/29
References ● Brian C.J. Moore, 2003 - An introduction to the psychology of hearing, 6th Edition
● Zwicker and Fastl, 2007 - Psychoacoustics: facts and models, 3rd edition
● Mandel, Ellis, 2009 - Speech & Audio Processing & Recognition - Lecture 4
● Other slides and scripts from professors Raake and Möller
● Huge help given by www.google.com/imghp to find images and references
29/29
AcousticLab.org: 23 Amplifon: 7 Blausen: 5
Flanagan: 10 GalleryHip: 14 Kidsdiscover: 6
Mandel, Ellis: 16 MixBag: 13 Moore: 17
Raake: 3, 4 RobinsonLibrary: 9 Skidmore.edu: 19
WhatWhenHow: 11 Wikipedia: 9, 19, 21, 22, 23 Wierstorf: 9
Zwicker, Fastl: 8 13 18 24 25 26
