Carol Y. Espy-Wilson
Elec. Comput. and Systems Eng. Dept., Boston Univ., 44 Cummington St., Boston, MA 02215
Suzanne Boyce
MIT, Cambridge, MA 02139
In Boyce and Espy-Wilson [J. Acoust. Soc. Am. 89, 1916(A) (1991)] the coarticulatory effects of American English /r/ on surrounding segments were reviewed, and data were presented to suggest that the articulatory gesture for /r/ is relatively incompressible. Here, data are reported from a larger study that supports the previous claims. Comparing the trajectories through the intervocalic consonant of /wavam/ and /wawam/ with /waram/, we estimate the duration of the /r/ trajectory to be around 150 ms. Further, the trajectory appears to be symmetrical. In addition to /r/'s in clusters with labial consonants, we looked at /r/'s following voiced stops /g/, /b/, and /d/. Given the commonly cited coarticulation hypothesis that (1) articulation will be initiated as soon as possible, and (2) that coarticulation will be more extensive when neighboring segments contain no incompatible gestures [W. Henke, unpublished Ph.D. dissertation, MIT (1966)], it was expected that /r/ trajectories would start earlier in words with labial consonants. However, it was found instead that /r/ trajectories remained the same for each consonant condition. This finding was aided by the fact that for each speaker in every condition at least one token was found where the full symmetrical /r/ trajectory could be observed. Results from 4 male and 4 female speakers of American English will be presented. Implications for coarticulation and speech recognition will be discussed.