Cross-language switching in Dutch-English bilinguals

A major issue in L2 research is whether bilinguals develop separate or merged phonetic systems. This study tested whether native speakers of Dutch, a language in which /p,t,k/ are realized with short-lag VOT values, would label the members of a VOT continuum ranging from /da/ to /ta/ differently when listening in a Dutch as opposed to English set. High-, mid-, and low-proficiency subgroups (ten each) were formed from a group of 50 Dutch university students on the basis of (a) global accent judgments by native British English listeners, (b) self-rating of ability to pronounce English, and (c) the VOT measured in their production of English /t/. A language specific set was established by having the subject produce and process Dutch or English speech prior to, or during, each half of the experiment. The mean location of the phoneme boundaries was only slightly longer in the English (35.6 ms) than Dutch set (33.5 ms). The effect of the language set was significant, but not the effect of proficiency or set x proficiency, indicating that the extent to which L2 learners adopt different, language-specific criteria in making phonetic judgments does not depend on language proficiency. However, the Dutch subjects showed a considerably larger shift in producing /t/ in English (60.3 ms) versus Dutch (22.8). English VOT was positively correlated with the global accent ratings, and subjects judged to have the least authentic English accent failed to distinguish /t/ in English and Dutch. [Work supported by NIH grant NS20963.]