Second language vowel perception.

This study explored the relation between first language (L1) and second language (L2) vowel perception using synthesized front vowel stimuli that varied in F1 and F2. Bilinguals identified vowel sounds in their L1 (Spanish) and L2 (English) on different days. Individuals’ responses provided English and Spanish F1×F2 maps of the front vowel space that could be compared to each other and to the maps of Spanish monolinguals to determine whether bilinguals have separate perceptual maps for each language, whether age at L2 acquisition or length of L2 use affects the maps, and whether L2 acquisition alters the L1 map. The results indicate that L1 and L2 maps of early L2 learners are more distinct from each other than those of late L2 learners. This finding supports the hypothesis that there is a critical age after which the sounds of a language cannot be learned authentically. No support was found for the notion that L2 acquisition affects L1 perceptual targets. An interesting peripheral finding is that bilinguals can produce vowel distinctions that they cannot perceive in isolated synthesized vowels.