Production of the Canadian English /ɹ/ by Mandarin-speaking second-language learners: Lip articulation and acoustic measures

Producing a speech sound in a second language (L2) can be challenging when it has a counterpart in the learner's first language (L1) but involves nuanced differences. The Canadian English /ɹ/ involves a slight lip rounding, absent in its Mandarin counterparts. This study asks whether and how Mandarin-L1 speakers' English /ɹ/ productions differ from English-L1 speakers. Forty Mandarin-L1 international students and 40 English-L1 speakers will be recruited to produce controlled non-words, words, and sentences containing /ɹ/. Their third formants (a characterizing acoustic measure of /ɹ/) and lip opening, spreading, and protrusion measures will be extracted from audio and facial kinematic recordings. Pilot analyses focused on 2 speakers' short non-word productions, paired with 3 vowels (/a i u/) in 3 positions (pre-, post-, inter-vocalic), 5 repetitions each (45 productions of each speaker). Linear regression indicated that the Mandarin-L1 speaker was not different from the English-L1 speaker in their third formants (p > 0.05) but produced less lip spreading and more protrusion (p < 0.001). Although the L2 learner achieved similar acoustic outcomes, their /ɹ/ articulation featured excessive lip rounding, a non-mandatory feature in English, indicating phonetic-level differences due to L1–L2 interaction. Full analyses will identify patterns related to L1, task complexity, and individual differences.