22 terms

Speech Science Exam 3 Production and Perception of Vowels

a vocal sound produced by relatively free passage of the air stream through the larynx and oral cavity
Nearly Periodic Complex Waves-made up of vowels
Continuous Aperiodic-consonants such as /s/, /f/
Source-filter theory
Sound from larynx is source of vibration, filter=vocal tract. Vocal tract filter is frequency-dependent, the vocal tract resonates the source signal by allowing certain frequencies to pass through the filter with greater amplitude than other frequencies. The characteristic resonances are called formants. P=spectrum of the sound pressure wave exiting the lips U, T & R make P
Average Male Vocal Tract Length
17.5 cm
Uniform Tube Model
The open end of the tube (lips) will have a velocity maximum, pressure minimum
For a tube closed at one end & open at the other
the tube will resonate best at a frequency that has a wavelength that is 4x the length of the tube.
Constriction at an antinode (lips) lowers the formant frequency
Formants relevant for vowels
F1, F2, F3
Loss/Gain radiated sounds
decrease of 12 at v.f., increase of 6 at lips
Differences b/t male & female harmonic structures
Men-closer together, women-further apart
Traditional description of vowels
described by tongue height and tongue advancement
Later description of vowels
1. Exist on a continuum 2. Vowels described by way they are perceived 3. Jaw and lip movt. characteristics are important
Vowel Quadrilateral
High/Low Front/Back eeyeah oowah + Small cap I, Upsilon, and ahse
Vowel Height
As the front vowels become more open (low) F1 increases F2 decreases
As the back vowels become more open F1 increases
Perception of vowel height related to F1
Tense vs. Lax
Tense=long vowels such as /i/, /e/, right hook reversed epsilon, lowercase o, schwar
Lax=short vowels such as /I/, schwa, epsilon, upsilon, open o
Neutral=ashe, /a/, /a/
onglide=articulatory starting point of the diphthong
offglide=articulatory ending point of diphthong
Differences between filters
Low pass=block high
High pass=block low
Bandpass=permits a range
Narrow bandwidth
frequency info.
Wide bandwidth
time info.
Sound spectography
displays formant structures harmonics & resonant characteristics of vocal tract
Bone=white, Tissue=gray, air=black
Instruments used to assess vocal tract functioning
MRI, CAT Scan, Ultrasound, X-Ray