The production of unstressed vowels in English by early and late
Korean- and Japanese-English bilinguals was investigated. All groups were
nativelike in having a lower fundamental frequency for unstressed as
opposed to stressed vowels. Both Korean groups made less of an intensity
difference between unstressed and stressed vowels than the native speakers
(NSs) of English as well as less of a difference in duration between the
two types of vowel than the NSs. The Japanese speakers, whose native
language has a phonemic length distinction, produced more nativelike
durational patterns. Finally, the vowel quality (first and second formant
frequencies) of unstressed vowels was different from the NS group's
for the late bilinguals, for whom unstressed vowels were widely dispersed
in the vowel space according to their orthographic representations, and
from the early Korean bilinguals, who substituted the Korean high central
vowel. The results are discussed in terms of the effect of the
phonological status of first language phonetic features and age of
acquisition.This work was supported by the
Korea Research Foundation (KRF-2003-042-A00048) and partially supported by
the National Institutes of Health (DC05132). A draft of this research was
presented at the English phonology workshop division held for the 50th
anniversary of the English Language and Literature Association of Korea
(June 2004). The authors would like to thank four anonymous SSLA
reviewers and Jonathan Loftin for their helpful comments on the
manuscript.