CHANGES IN VOICE ONSET TIME IN YOUNG AND OLDER MEN

This investigation studied the effect of aging on the articulatory-laryngeal adjustments required for speech. Specifically, measurements of vocal onset time (VOT) were obtained from 45 healthy mate speakers. The speakers were divided into three groups of 15 subjects. The young control group contained healthy male speakers aged 25-39 years. Groups 1 and 2 included healthy older speakers aged 60-69 years and 70-79 years respectively. Each speaker produced ten tokens of six different CVC words embedded in a carrier phrase for spectrographic analysis. Measures of VOT were then obtained for bilabial, alveolar, and velar English prevocalic stop consonants. Findings revealed a clear and significant reduction of VOT for the phonemes /p/ and /t/ in the speech of older subjects. The results demonstrated that this acoustic measure can distinguish between groups of young and older male speakers. This voice characteristic may prove to be a major factor influencing listener perception.