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

3pSP6. Inferring degree of coarticulation and relational invariance of stop place in CV's using locus equations.

Court S. Crowther

Dept. of Linguist., UCLA, 3125 Campbell Hall, Los Angeles, CA 90024-1543

Locus equations relating target and onset frequency of F2 (F2t and F2o, respectively) have been successful in distinguishing stop consonant place of articulation independent of vowel context [e.g., Sussman et al., J. Acoust. Soc. Am. 90, 1309--1325 (1991)]. These linear equations are of the form F2o=a(F2t)+c. The slope parameter a is generally interpreted as indicating not only place of articulation, but extent of coarticulation [e.g., D. Krull, PERILUS V, 43--61 (1987)] as well. The intercept parameter c often is not interpreted explicitly, except in cases where the slope is found to be near zero. The locus equation technique is considered from several different viewpoints. Locus equations are analyzed empirically by examining changes that occur in estimated slope and intercept when a trained phonetician simulates different degrees of C-V coarticulation. Differences in extent of coarticulation are also measured using electropalatography, and these measurements are compared with slope and intercept parameters derived from the acoustic data. Finally, the Locus equation technique is compared with other methods for inferring coarticulation, including absolute comparisons of individual F2o and F2t frequency differences. [Work supported by NIH.]