Acoustic characteristics of glides /j/ and /w/: Interactions with phonation frequency.

Abstract

As part of a larger study of acoustic characteristics of glides, patterns in the movements of the fundamental frequency of phonation (F0) were measured during utterances of the glide segments /j/ and /w/. Two male and two female American English speakers produced intervocalic glides in six different vowel contexts and five different prosodic contexts. F0 contours show pronounced valleys during glide segments, in which the frequency of phonation is decreased relative to the surrounding prosodic contour. These valleys occur more frequently for higher fundamental frequencies, as in female speech. Effects of surrounding vowel and prosodic contexts were also observed, with F0 valleys more often occurring during glides when the following vowel is pitch accented or when the height of the surrounding vowels is high. The results are interpreted in terms of acoustic loading on the glottal source; the effects of which are most pronounced when a narrow vocal tract constriction (as in a glide segment) lowers the first formant frequency into the range of F0. This interaction with F0 may provide an enhancing acoustic cue to the presence of glides in the speech stream, particularly for female speakers or high-vowel contexts. [Work supported in part by NIH Grant No. DC00075.]