vowels vowels: articulatory description (ferrand, 2001) tongue position
Post on 21-Dec-2015
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Vowels: Articulatory Description Degree of lip rounding
Rounded Unrounded
Degree of tension Tense Lax
Vocal tract as a tube Tubes have physical
characteristics Tubes are acoustic
resonators Acoustic resonators
have frequency response curves (FRC) (or transfer functions)
Physical characteristics dictate FRC
Frequency response curve (FRC) FRC peaks – resonant
or formant frequency Resonators have an
infinite number of formants
F1, F2, F3 … denotes formants from low to high frequency
F1 F2 F3 F4
Formant Patterns for the “Noncentral” (i.e., omitting
/ú/ and /ü/) Monophthongal Vowels of American English (based on Peterson & Barney averages)
Characteristics affecting filter properties
Overall length Whether it is closed at either or both ends Cross-sectional area along its length
Uniform tube closed at one end
First resonance or formant
F1 = c/4lWhere
c=speed of sound (35,000 cm/sec)
l = length of the tube
males ~ 17.5 cm
females ~ 14 cm
Higher resonant/formant frequencies are odd multiples of F1
For example, F1 = (c/4l )*1
F2 = (c/4l )*3
F3 = (c/4l )*5
The vocal tract Can be (roughly) uniform in shape Can also be take on non-uniform shapes Non-uniform tubes
Have a more complex area function Does not allow simple calculations of resonances
Key point Vocal Tract has a variable shape, therefore
It is a variable resonator Can have a variety of area functions Can generate a variety of frequency response
curves
What distinguishes vowels in production and perception?
Resonant (formant) Frequency F1, F2 frequency are
particularly important F3 frequency plays a
smaller role
Landmark study: Peterson and Barney (1952)
Median values based on lab measures