Influence of Postvocalic Consonants on Vowel Duration in Esophageal Speech

Abstract

The durations of vowels preceding voiced-voiceless stops in utterances produced by three esophageal speakers and three normal speakers were measured. Vowels were significantly longer before voiced stops than before voiceless stops for both esophageal and normal speakers. For either postvocalic consonant environment, the average absolute durations of the vowels of the esophageal speakers were longer than those of the normal speakers. Speaker-group comparisons revealed no significant difference in vowel duration preceding voiceless stops; however, the average absolute duration of vowels preceding voiced stops was significantly longer for the esophageal group. Speaker-group comparisons revealed no significant differences in the relative differences in vowel duration preceding voiced-voiceless stops. The data were interpreted to support the view that the vowel length variation observed is a language-specific behavior governed by a phonological rule of the English language, rather than simply a language-universal behavior governed by inherent physiological characteristics of the speech-production mechanism. Moreover, it was suggested that this phonological rule is a lengthening rule, which lengthens vowels before voiced consonants, rather than a shortening rule, which shortens vowels before voiceless consonants.