Impact of language dominance on phonetic transfer in Cantonese-English bilingual language switching

Abstract

Previous studies have suggested that bilinguals were susceptible to phonetic interaction between their two phonetic systems during online speech processing. However, little is known about the phonetic control of bilinguals’ speech production. The study investigated how early Cantonese-English bilingual adults with various language dominance profiles (including Cantonese-dominant, English-dominant and balanced bilinguals) differed in terms of phonetic control in a language switching paradigm. With the measure of voice onset time (VOT), we found that unbalanced bilinguals and balanced bilinguals responded differently to language switching. Unbalanced bilinguals tended to shift their VOT production of dominant language towards their non-dominant language during language switching, but not in the opposite direction. However, we did not observe any effect of language switching on speech production in balanced bilinguals. The results support the Inhibitory Control Model, and extend the model from lexical level to phonetic level of bilingual speech production in unbalanced bilinguals. Moreover, the results also imply that the underlying mechanism for bilingual speech production for highly balanced bilinguals may or may not differ from unbalanced bilinguals.