2pSC11. An acoustic evaluation of variation in the overlap of consonant and vowel gestures induced by speaking rate change.

Session: Tuesday Afternoon, May 14

Time: 3:45

Author: Kris Tjaden
Location: Dept. of Communicative Disorders, San Diego State Univ., 5500 Campanile Dr., San Diego, CA 92182
Author: Gary Weismer
Location: Univ. of Wisconsin, Madison, WI 53705


There is a growing body of empirical data supporting a gestural-based view of speech production in which adjacent speech gestures temporally and spatially overlap one another. Recent work suggests that certain acoustic measures are sensitive to changes in the overlap of adjacent consonant and vowel gestures [G. Weismer et al., J. Phon. 23, 111--126 (1995); E. Zsiga, J. Phon. 22, 121--140 (1994)]. Utilizing a graded speaking rate task, eight speakers produced 160 repetitions of ten target words embedded in a carrier phrase. F2 onset frequency, measured at the consonant--vowel boundary of test syllables, was used to index the degree of spectral-temporal overlap of adjacent consonant and vowel gestures. Regression analyses were used to evaluate the extent to which F2 onset predicted temporal variability in F2 formant trajectories due to speaking rate change. Results suggest that consonant and vowel gestures do not simply temporally slide away from each other with slowed speaking rate. Rather, modifications in the form and magnitude of vowel gestures are required to account for the present acoustic data. An empirically based acoustic model of variation in gesture overlap induced by speaking rate change is offered. Individual speaker differences also are discussed.

from ASA 131st Meeting, Indianapolis, May 1996