Acoustic characteristics of English intonation in Mandarin-English bilinguals

In addition to segmental level contrast, Mandarin Chinese uses two levels of prosodic contrast, tone at word level and intonation at utterance level, to convey linguistic meaning. Mandarin speakers need to adjust fundamental frequency (f0) to maintain intelligibility at both word- and utterance-level. For English speakers, f0 changes at utterance level for intonation were not confined by word-level tonal requirements. The present study investigated the acoustic characteristics of English intonation produced by Mandarin-English bilinguals at different developmental stages. Six- and nine-year-old Mandarin-English bilingual children and adults (seven per group) completed the speech production tasks. Stimuli were three types of carrying sentences (statement, question with and without inversion) in English. Carrying sentences end with monosyllabic target words that are phonetically similar in Mandarin (e.g., [di], 帝 Dee). Average f0 and magnitude of f0 change were measured within word and over the entire utterance, and compared among age groups. Results indicated (1) average f0 was the highest in questions without inversion, followed by questions with inversion. Statements showed the lowest average f0. (2) Magnitude of f0 change was larger in speakers with more English exposure and in older children. Sentence type, language experience, and developmental age appear to influenced average f0 and magnitude of f0 change.