Production of phonetic and phonological contrast by heritage speakers of Mandarin.

This study tested the hypothesis that heritage speakers of a minority language, due to their childhood experience with two languages, would outperform late learners in producing contrast: language-internal phonological contrast, as well as cross-linguistic phonetic contrast between similar, yet acoustically distinct, categories of different languages. To this end, production of Mandarin and English by heritage speakers of Mandarin was compared to that of native Mandarin speakers and native American English-speaking late learners of Mandarin in three experiments. In experiment 1, back vowels in Mandarin and English were produced distinctly by all groups, but the greatest separation between similar vowels was achieved by heritage speakers. In experiment 2, Mandarin aspirated and English voiceless plosives were produced distinctly by native Mandarin speakers and heritage speakers, who both put more distance between them than late learners. In experiment 3, the Mandarin retroflex and English palato-alveolar fricatives were distinguished by more heritage speakers and late learners than native Mandarin speakers. Thus, overall the hypothesis was supported: across experiments, heritage speakers were found to be the most successful at simultaneously maintaining language-internal and cross-linguistic contrasts, a result that may stem from a close approximation of phonetic norms that occurs during early exposure to both languages.