A Tale of Two Features: Perception of Cantonese Lexical Tone and English Lexical Stress in Cantonese-English Bilinguals.

This study investigated the similarities and differences in perception of Cantonese tones and English stress patterns by Cantonese-English bilingual children, adults, and English monolingual adults. All three groups were asked to discriminate pairs of syllables that minimally differed in either Cantonese tone or in English stress. Bilingual children's performance on tone perception was comparable to their performance on stress perception. By contrast, bilingual adults' performance on tone perception was lower than their performance on stress perception, and there was a similar pattern in English monolingual adults. Bilingual adults tended to perform better than English monolingual adults on both the tone and stress perception tests. A significant correlation between tone perception and stress perception performance was found in bilingual children but not in bilingual adults. All three groups showed lower accuracy in the high rising-low rising contrast than any of the other 14 Cantonese tone contrasts. The acoustic analyses revealed that average F0, F0 onset, and F0 major slope were the critical acoustic correlates of Cantonese tones, whereas multiple acoustic correlates were salient in English stress, including average F0, spectral balance, duration and intensity. We argue that participants' difficulty in perceiving high rising-low rising contrasts originated from the contrasts' similarities in F0 onset and average F0; indeed the difference between their major slopes was the only cue with which to distinguish them. Acoustic-perceptual correlation analyses showed that although the average F0 and F0 onset were associated with tone perception performance in all three groups, F0 major slope was only associated with tone perception in the bilingual adult group. These results support a dynamic interactive account of suprasegmental speech perception by emphasizing the positive prosodic transfer between Cantonese tone and English stress, and the role that level of bilingual language experience and age play in shaping suprasegmental speech perception.