Effect of speaking rate on individual talker differences in voice-onset-time

Abstract

Recent findings indicate that individual talkers systematically differ in phonetically relevant properties of speech. One such property is voice-onset-time (VOT) in word-initial voiceless stop consonants: at a given rate of speech, some talkers have longer VOTs than others. It is also known that for any given talker, VOT increases as speaking rate slows. We examined whether the pattern of individual differences in VOT holds across variation in rate. For example, if a given talker has relatively short VOTs at one rate, does that talker also have relatively short VOTs at a different rate? Numerous tokens of /ti/ were elicited from ten talkers across a range of rates using a magnitude-production procedure. VOT and syllable duration (a metric of speaking rate) were measured for each token. As expected, VOT increased as syllable duration increased (i.e., rate slowed) for each talker. However, the slopes as well as the intercepts of the functions relating VOT to syllable duration differed significantly across talkers. As a consequence, a talker with relatively short VOTs at one rate could have relatively long VOTs at another rate. Thus the pattern of individual talker differences in VOT is rate dependent. [Work supported by NIH/NIDCD.]