English lexical stress produced by native (L1) Bengali speakers compared to native (L1) English speakers: an acoustic study

摘要

English lexical stress is acoustically related to combination of duration, intensity, fundamental frequency (F_0) and vowel quality. Errors in any or all of these correlates could interfere with production of the stress contrast, but it is unknown which correlates are most difficult for L1 Bengali speakers to acquire. This study compares the use of these correlates in the production of English lexical stress contrasts by 10 L1 English and 20 L1 Bengali speakers. The results showed that L1 Bengali speakers produced significantly less native like stress patterns, although they used all four acoustic correlates to distinguish stressed from unstressed syllables. L1 English speakers reduced vowel duration significantly more in the unstressed vowels compared to L1 Bengali speakers and degree of intensity and F_0 increase in stressed vowels by L1 English speakers was higher than that by L1 Bengali speakers. There were also significant differences in formant patterns across speaker groups, such that L1 Bengali speakers produced English like vowel reduction in certain unstressed syllables, but in other cases, L1 Bengali speakers had tendency to either not reduce or incorrectly reduce vowels in unstressed syllables. The results suggest that L1 Bengali speakers' production of English lexical stress contrast is influenced by L1 language experience and L1 phonology.