Effects of clear speech on duration and fundamental frequency of vowels produced by monolingual and bilingual talkers

Abstract

Prosodic characteristics of vowels produced by monolingual and bilingual talkers were investigated. Ten monolingual, 15 early Spanish-English bilingual (age of onset of immersion of age 12 or earlier), and ten late Spanish-English bilingual (age of onset of immersion of age 15 or later) talkers produced the target words ‘‘bead, bid, bayed, bed, bad,’’ and ‘‘bod’’ in conversational and clear speech styles. Vowel duration was computed, and F0 measurements were made at 20%, 50%, and 80% of the vowel duration. A significant group by style by vowel interaction showed that monolingual and early bilingual talkers enhanced inherent duration differences between target vowels by lengthening long vowels significantly more than short vowels in clear speech. The vowels of the late bilingual talkers, by contrast, became more alike in duration in clear than in conversational speech. The monolingual talkers showed a falling F0 pattern from 20% to 80% of the vowel duration in both styles; the late bilingual talkers showed a flat or rising F0 pattern in both styles; and the early bilingual talkers showed a flat or rising pattern in conversational speech, but a falling pattern in clear speech. [Work supported by NIH-NIDCD ♯5R03DC005561.]