Phonetic variability in bilinguals’ acquisition of native-vowel category contrasts.

Abstract

Previous research has shown that bilingual infants and toddlers follow a slightly different developmental pattern in building and stabilizing some native vowel contrastive categories, compared to monolingual populations. Once in the lexical stage, bilingual toddlers do not always show the expected mispronunciation effect when presented with familiar words in which a vowel change has been introduced. To better understand bilinguals’ protracted process in setting the boundaries for certain, perceptually close, native vowel categories, a phonetic analysis of the input characteristics was undertaken. Speech samples containing target words with Catalan midfront vowel sounds were recorded from two groups of Catalan-speaking mothers from monolingual and bilingual environments, differing in the use of their L2 (Spanish). First and second formant values of the target vowels were obtained and compared between groups. The vowels were always correctly and contrastively produced, but bilinguals’ formant values differed significantly from monolinguals’: categories were closer in space and greater variability in production was found. Young bilinguals’ sensitivity to phonetic variability in the words they hear may constrain the development of neat representations of contrastive vowel categories in the early lexicon. [Work supported by CONSOLIDER 2010 Program (CSD2007-012).]