Production of the English /ɹ/ by Mandarin-English Bilingual Speakers.

Rhotic sounds are some of the most challenging sounds for L2 learners to acquire. This study investigates the production of English rhotic sounds by Mandarin-English bilinguals with two English proficiency levels. The production of the English /ɹ/ by 17 Mandarin-English bilinguals was examined with ultrasound imaging and compared with the production of native English speakers. The ultrasound data show that bilinguals can produce native-like bunched and retroflex gestures, but the distributional pattern of tongue shapes in various contexts differs from that of native speakers. Acoustically, the English /ɹ/ produced by bilinguals had a higher F3 and F3-F2, as well as some frication noise in prevocalic /ɹ/, features similar to the Mandarin /ɹ/. Mandarin-English bilinguals did produce language-specific phonetic realizations for the English and Mandarin /ɹ/s. There was a positive correlation between language proficiency and English-specific characteristics of /ɹ/ by Mandarin-English bilinguals in both articulation and acoustics. Phonetic similarities facilitated rather than hindered L2 speech learning in production: Mandarin-English bilinguals showed better performance in producing the English /ɹ/ allophones that were more similar to the Mandarin /ɹ/ (syllabic and postvocalic /ɹ/s) than producing the English /ɹ/ allophone that was less similar to the Mandarin /ɹ/ (prevocalic /ɹ/). This study contributes to our understanding of the mechanism of speech production in late bilinguals.