This study assessed the effect of English-language experience on non-native speakers' production and perception of English vowels. Twenty speakers each of German, Spanish, Mandarin, and Korean, as well as a control group of 10 native English (NE) speakers, participated. The non-native subjects, who were first exposed intensively to English when they arrived in the United States (mean age = 25 years), were assigned to relatively experienced or inexperienced subgroups based on their length of residence in the US (M = 7.3 vs. 0.7 years). The 90 subjects' accuracy in producing English /i I ε æ/ was assessed by having native English-speaking listeners attempt to identify which vowels had been spoken, and through acoustic measurements. The same subjects also identified the vowels in synthetic beat-bit (/i/-/I/) and bat-bet (/æ/-/ε/) continua. The experienced non-native subjects produced and perceived English vowels more accurately than did the relatively inexperienced non-native subjects. The non-native subjects' degrees of accuracy in producing and perceiving English vowels were related. Finally, both production and perception accuracy varied as a function of native language (L1) background in a way that appeared to depend on the perceived relation between English vowels and vowels in the L1 inventory. © 1997 Academic Press Limited.
