ASA 130th Meeting - St. Louis, MO - 1995 Nov 27 .. Dec 01

2aSC21. Modeling the articulatory dynamics of two kinds of stress.

K. Bretonnel Cohen

Mary E. Beckman

Dept. of Linguistics, Ohio State Univ., 1712 Neil Ave., Columbus, OH 43210-1298

Jan Edwards

Marios Fourakis

Ohio State Univ., Columbus, OH 43210

A study reported at an earlier meeting of this society examined fine-grained timing cues to three levels of stress by comparing jaw kinematics in intonationally accented syllables (with full vowels), unaccented syllables (with full vowels), and completely stressless (reduced-vowel) syllables. For all four speakers in the study, measured values for movement duration, displacement, and peak velocity were consistently largest in the accented syllables and smallest in the reduced-vowel syllables. This study examines the relationships among these kinematic measures using two different models of the underlying gestural dynamics. The first generated shorter (less stressed) syllables by decreasing the latency of the closing gesture relative to the opening gesture without changing the targeted gestural speed or displacement. The second generated shorter syllables by changing the targeted gestural speed, but decreasing targeted displacement more, so as not to increase the predicted velocities. The first model generated predicted durations, which were closer to the observed distribution of durations among the three stress types, whereas the second generated predicted displacments that were closer to the observed distribution of displacements. Neither generated the observed distribution of velocities, suggesting that a hybrid model is necessary.