Acoustic Evidence for Gestural Overlap in Consonant Sequences*

Acoustic evidence for temporal overlap of the two closure gestures in the environment VC#CV was investigated. It was hypothesized that evidence of C2 would be found in the VC formant transitions and would increasingly dominate the transitions as rate (and by hypothesis, overlap) increased. Twenty repetitions (ten at a normal rate and ten at a rapid rate) of word pairs where the first word ended in IdJ and the second began with Ip/, IV, or IkJ were elicited in a sentence context from four subjects. F2 and F3 transitions from the midpoint of VI to just before closure were then measured. In all environments, C2 had a clear influence on the VC formant transitions. The rate effects were less clear. For the Id#k / environment, a significant correlation was found between more prominent velar transitions and increasing ratio of vowel duration to consonant closure duration, which may be considered a measure of increasing consonant overlap. The acoustic influence of C2 on VI suggests considerable temporal overlap of the two closure gestures, and at least for the d#k case, increasing overlap as a function of fluency. 1