Production of bite-block vowels: acoustic equivalence by selective compensation.
Acoustic and articulatory data are reported for steady state vowels produced both normally and with a bite block. The formant patterns of the bite-block vowels were found to approximate those of the naturally spoken vowels. Measurements derived from lateral view still x-ray films showed that the bite blocks induce drastic articulatory reorganization. Using a mandibular frame of reference, we found that speakers compensated for a large bite block by using supershapes of the tongue and the lips (for [u] and [o]). Comparing the two productions using a maxillary frame of reference, we noted that compensation was maximum at the points of maximum constriction and incomplete or partial at points where the vocal-tract area was large. A computer simulation of our speakers' compensatory strategy revealed that they behaved optimally according to acoustic theory. These findings suggest that a vowel target is coded neurophysiologically in terms of acoustically significant area-function, specifically, by information related to cavity configuration at points of maximum constriction.
D000328:Adult; D006801:Humans; D007103:Immobilization; D007568:Jaw / Q000502:physiology*; D007830:Larynx / Q000502:physiology; D008046:Lip / Q000502:physiology; D008297:Male; D009055:Mouth / Q000502:physiology; D009068:Movement; D010614:Pharynx / Q000502:physiology; D010700:Phonetics; D013060:Speech / Q000502:physiology*; D013061:Speech Acoustics