The vowel systems of Quichua-Spanish bilinguals. Age of acquisition effects on the mutual influence of the first and second languages.

This study investigates vowel productions of 20 Quichua-Spanish bilinguals, differing in age of Spanish acquisition, and 5 monolingual Spanish speakers. While the vowel systems of simultaneous, early, and some mid bilinguals all showed significant plasticity, there were important differences in the kind, as well as the extent, of this adaptability. Simultaneous bilinguals differed from early bilinguals in that they were able to partition the vowel space in a more fine-grained way to accommodate the vowels of their two languages. Early and some mid bilinguals acquired Spanish vowels, whereas late bilinguals did not. It was also found that acquiring Spanish vowels could affect the production of native Quichua vowels. The Quichua vowels were produced higher by bilinguals who had acquired Spanish vowels than those who had not. It is proposed that this vowel reorganization serves to enhance the perceptual distinctiveness between the vowels of the combined first- and second-language system. Copyright 2003 S. Karger AG, Basel