Production of lexical stress in non-native speakers of American English: kinematic correlates of stress and transfer.

PURPOSE To assess the influence of second language (L2) proficiency on production characteristics of rhythmic sequences in the L1 (Bengali) and L2 (English), with emphasis on linguistic transfer. One goal was to examine, using kinematic evidence, how L2 proficiency influences the production of iambic and trochaic words, focusing on temporal and spatial aspects of prosody. A second goal was to assess whether prosodic structure influences judgment of foreign accent. METHOD Twenty Bengali-English bilingual individuals, 10 with low proficiency in English and 10 with high proficiency in English, and 10 monolingual English speakers, participated. Lip and jaw movements were recorded while the bilingual participants produced Bengali and English words embedded in sentences. Lower lip movement amplitude and duration were measured in trochaic and iambic words. Six native English listeners judged the nativeness of the bilingual speakers. RESULTS Evidence of L1-L2 transfer was observed through duration but not amplitude cues. More proficient L2 speakers varied duration to mark iambic stress. Perceptually, the high-proficiency group received relatively higher native-like accent ratings. Trochees were judged as more native than iambs. CONCLUSIONS Even in the face of L1-L2 lexical stress transfer, nonnative speakers demonstrated knowledge of prosodic contrasts. Movement duration appears to be more amenable than amplitude to modifications.