Effects of stress and final consonant voicing on vowel articulation and formant patterns

Abstract

Stress level and voicing of a postvocalic consonant are two factors known to influence vowel duration. In the present study, vowel durations, jaw and lower lip movement data, and formant data were examined for a set of b‐vowel‐consonant utterances differing in stress and final consonant voicing. As expected, vowel durations were greater for stressed utterances and for utterances containing voiced final consonants (voiced utterances). Articulator lowering and raising gestures were more rapid and more extensive for stressed versus unstressed utterances. At the acoustic level, stressed uterances demonstrated more rapid initial formant transitions and more extreme steady‐state frequencies than unstressed utterances. In contrast, increases in vowel duration due to voicing were not accompanied by increases in the velocity or magnitude of articulatory gestures. In addition, voiced utterances did not demonstrate steeper formant transitions or more extreme steady‐state frequencies than voiceless utterances. The results demonstrate that stress‐related and voicing‐related changes in vowel duraton are accomplished by separate and distinct transformations with observable consequences at both the articulatory and acoustic level. [Work supported by NINCDS and the Stuttering Center, Baylor College of Medicine.]