ASA 127th Meeting M.I.T. 1994 June 6-10

3aED5. Speaking rate and associated kinematic patterns of tongue movements.

Henry Y. Lu

Joseph S. Perkell

Melanie L. Matthies

Speech Commun. Group, Res. Lab. of Electron., MIT, 50 Vassar St., Rm. 36-595, Cambridge, MA 02139

Kinematically based measures of effort for tongue movements were examined for a speaker with a cochlear implant. Turning the speech processor of the implant on- and off-induced changes in the subject's speaking rate. An electromagnetic midsagittal articulometer (EMMA) was used to track movements of the tongue body toward and away from the steady-state target for the /u/ vowel in the utterance ``...who hid...''. Although the tongue body movements toward the /u/ were quite small---on the order of a millimeter---kinematic measurements for those movements still exhibited relationships that were strikingly similar to results of past findings, which have shown strong relations between movement distance and duration. Similarly, values for velocity profile shape (the ratio of peak velocity to average velocity) appeared to follow increases in movement duration. According to the measures of peak velocity and energy, the most ``effort'' for these small movements was exerted in the condition when the cochlear implant had been off for the longest time. Examination of the number of velocity peaks and of tongue body trajectories for each utterance revealed that ``smoother'' and less effortful movements appeared with greater frequency when the cochlear implant was on. [Work supported by N.I.D.C.D.]