Acoustics of Consonants Flashcards
Sound Sources
Vowels usually produced with a periodic source of sound
Consonants may use an aperiodic sound source or a combination of periodic and aperiodic sources; never periodic only (vowels)
Vocal Fold Sound Source
Vocal Tract = Resonator
Periodic
Vowels
Dipthongs
SemiVowels
Liquids
Vocal Tract Sound Source
Vocal Tract = Resonator
Aperiodic
Stops
Fricatives
Affricates
Plosives
p/b, t/d, g/k
often called plosive sounds because of burst of noise
Have the greatest degree of constriction to the breath stream
Complete occlusion of the vocal tract
Two simultaneous occlusions are essential
Velopharyngeal closure
Occulsion by the lips or tongue – occlusions are identical to those made by the nasals
Fricatives
f/v, th/th, s/z, sh/zh, h
Produced by compressing a continuous flow of air through a constriction formed by closely approximating two articulators
Four primary places of articulation: Labiodental Linguadental Alveolar Postalveolar
Affricates
ch/dz
English has only two affricates (ch) and (j)
A stop with a fricative release
Acoustically present a combination of stop and fricative features
Silent gaps
Bursts of noise
Extended duration of aperiodicity
Glides
w, y
Nasals
m, n, ng
Liquids
l, r
Vocal Folds & Vocal Tract
Vocal Tract = Resonator
Mixed Periodic and Aperiodic
Voiced Plosives
Voiced Fricatives
Voiced Affricates
Resonant Consonants & SemiVowels
Glides - /w/ “we” (almost resembles [ui]) /j/ “you” (resembles [iu])
Liquids - /r/ “right” /l/ “light”
Vocal tract modifier is the tongue and lips
The vocal tract is relatively open for semivowels; classified as consonants because they are always located next to vocalic nuclei – never /twn/ or /pjk
Nasals
Velopharyngeal port – vocal tract modifier
Also resonant consonants
Three nasal consonants /m/, /n/, /ng/
Levator palatini is the muscle primarily responsible for closing the velopharyngeal port
Pharyngeal wall movement accompanies velopharyngeal closure
Velopharyngeal Port Closure
Maximum velar elevation and backing occur during the articulation of oral consonants – particularly stops and affricates
Leakage of air into the nasal cavity makes it impossible to produce stops and fricatives acceptably
Production of Nasals
Velum is low – VP port is open
Oral cavity is occluded in one of three ways
/m/ lips are brought together
/n/ tip of tongue touches the upper alveolar ridge
/ng/ tongue dorsum touches the posterior part of the hard palate or anterior of soft palate
“some”, “sun”, “sung” – feel the difference in placement
Sound is resonated in the closed oral cavity, the pharyngeal cavity and the nasal cavity
Nasal Acoustics
Acoustically they are weak sounds
Their articulation creates antiresonances- frequency regions in which the amplitudes of the source components are severely attenuated (a filtering affect)
The elongation of the vocal tract caused by the opening of the velopharyngeal port
results in a broader band of frequency response and broadly tuned resonators are more highly damped than narrowly tuned ones