ASA 129th Meeting - Washington, DC - 1995 May 30 .. Jun 06

5aSC9. Functional data analyses of lip motion.

J. O. Ramsay

Dept. of Psych., McGill Univ., 1205 Dr. Penfield Ave., Montreal, PQ H3A 1B1, Canada

K. G. Munhall

Queens University, Kingston, ON, Canada

V. L. Gracco

Haskins Labs., New Haven, CT 06511

D. J. Ostry

Montreal, PQ H3A 1B1, Canada

The vocal tract's motion during speech is a complex patterning of the movement of many different articulators according to many different time functions. Central issues are the accurate description of the shape of the vocal tract and determining how each articulator contributes to this shape. Techniques are described that provide useful tools for describing multivariate functional data such as the measurement of speech movements. The choice of data analysis procedures has been motivated by the need to partition the articulator movement in various ways: movement start- and end-effects separated from shape effects, effects due to different syllables, and the splitting of within-sensor variation from between-sensor overall variation. The techniques of functional data analysis seem admirably suited to the analyses of phenomena such as these. Familiar multivariate procedures such as analysis of variance and principal components analysis have their functional counterparts, and these reveal in a way more suited to the data the important sources of variation in lip motion. Finally, it is found that the analyses of acceleration were especially revealing in considering the character of possible control mechanisms. [Work supported by NIH Grant DC-00594.]