Influences of Phonetic Sequences and Stress on Fundamental Frequency Contours of Isolated Words

Abstract

At vowel onset following unvoiced consonants in /həCVC/ utterances spoken by two talkers, F0 began high (30% higher than in /ə/), and fell about 7% in the first 5 csec. At closure of voiced oral obstruents, F0 suddenly dipped about 10%, remained flat, suddenly rose about 25% at opening of closure, and, after vowel onset, gradually rose (an average of 8% in the first 10 csec). The high/low feature of the vowel and the manner and place of prevocalic consonant articulation had progressively less effect on vowel F0 values. The final consonant had no apparent effect on F0 contours in the vowel. As previous synthesis work has suggested, the fall or rise of F0 in the initial portion of a vowel appears to be a cue to the state of voicing of previous consonants. Initial and peak F0 values in the vowel also can indicate state of consonant voicing. However, F0 contours in bisyllabic words with contrasting stress patterns and similar phonemic sequences (e.g., permit, permit) showed that (1) an initially falling F0 in a vowel may indicate either previous unvoiced consonant or an unstressed vowel, and (2) a rising F0 contour may indicate either a word-initial vowel, a preceding voiced consonant, or a stressed vowel.