Acoustic influence of L1 Spanish on L2 English vowel production

Abstract

The strength of influence of the L1 vowel inventory on L2 vowel acquisition is well-documented: learners who identify an L2 phoneme as belonging to an L1 category may fail to establish a distinct category for the new phoneme (Flege, 2002), while those who establish a new category for an L2 vowel may ultimately exhibit more native-like pronunciation (Bohn & Flege, 1992). In learning an L2 with many more vowel categories than the L1, as Spanish-English bilinguals must, speaker-specific category assimilation and discrimination are important contributors to the level of accentedness and intelligibility. This study examines the influence of L1 vowels on L2 production via formants and duration of stressed and unstressed L1 Spanish/L2 English vowels. Ten advanced Spanish-English bilinguals completed a shadowing task in both languages, producing five vowels from each language in various target words. Examined in the aggregate, most vowels remained spectrally distinct along both the F1 and F2 dimensions, with a few categories collapsed across one dimension or the other; unstressed vowels raised in both languages, but raised further in English than Spanish. However, interspeaker differences in the patterns of category assimilation necessitate an individual analysis, highlighting the high level of variation in acquisition across individuals.