Physiological control of sibilant durations

Abstract

In an earlier paper [S. Hamlet and M. Stone, J. Acoust. Soc. Am. 61, S7 (A) (1977)] tongue overshoot was reported to occur on /s/ and /z/, when subjects first attempted to speak with a dental prosthesis with 4 mm of alveolar thickness. The duration of frication for /s/ under that condition was no longer than for /s/ spoken when wearing a thin prosthesis, or when speaking without a prosthesis. Duration of /z/ was greater than in natural speech. Multiple explanations exist: (1) Timing of tongue contact for /s/ may have been altered as a compensatory attempt. (2) Duration of /s/ frication may be governed more closely by laryngeal adjustments than by tongue gestures. Special modifications of a palatography system were made so that measurements of duration of tongue contact could be made with an accuracy of 1 or 2 msec. Measurements of cessation and onset of voicing were made from pretracheal accelerometer signals. Preliminary results are discussed, based on a small number of subjects. [Work supported by NIH.]