Vowel space and formant dynamics of vowels produced by monolingual and bilingual talkers in conversational and clear speech styles

Abstract

Formant frequency characteristics of vowels produced by monolingual and bilingual talkers were compared. Ten monolingual, 15 early Spanish-English bilingual (age of onset of immersion is 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. Measurements of F1 and F2 were made at 20%, 50%, and 80% of vowel duration. Significant group effects for F1 and F2 at 50% of vowel duration showed similar locations and distances between the vowels for the monolingual and early bilingual talkers, except that F2 values were significantly higher for the early bilingual than for the monolingual talkers for the vowels in the target words ‘‘bead, bid,’’ and ‘‘bed.’’ Smaller between-vowel distances were found for both F1 and F2 for the late bilingual talkers, especially for the vowels in the target words ‘‘bead, bid, bayed,’’ and ‘‘bed.’’ Changes observed in clear speech were relatively modest for all three groups. Comparisons between formant dynamic vectors and angles across groups and style and between talkers showing large versus small degrees of clear speech intelligibility benefit will be presented. [Work supported by NIH-NIDCD No. 5R03DC005561.]