Abstract
In an earlier study (Ryalls, Zipprer and Baldauff, 1997) significant differences in Voice Onset Time (VOT) production were found between younger males and younger females, as well as between African-American and Caucasian-American speakers. In this study we attempted to replicate these significant effects for gender and ethnic background in a group of older speakers. Participants in this study were healthy normal speakers between 50 and 70 years of age and included 10 African-Americans and 10 Caucasian-Americans with 10 males and 10 females. Speakers in this study produced real words with each of the 6 stop consonants of English (/p/, /t/, /k/; /b/, /d/, /g/) combined with the three extreme vowels (/i/, /a/, /u/) in monosyllabic words ending with a voiceless stop. Each of these 18 stimuli were then read at least five times in random order within a repetition and recorded onto Digital Audio Tape (DAT). The Brown University Laboratory Interactive Speech System (BLISS, Mertus, 1999) was used to display waveforms and measure VOT for three of the repetitions for a total of 54 measures per speaker. An Analysis of Variance indicated no significant effects for either ethnic background or gender. However, a comparison with the previous VOT data from younger speakers revealed a significant difference with the present data from older speakers. The results of this study are discussed in the context of past findings in the published literature.