Perceptual switching in bilinguals

Three groups of subjects, monolingual English speakers, monolingual Spanish speakers, and English–Spanish bilinguals, identified a series of naturally produced syllables which varied in voice onset time (from /ba/ to /pa/). The two monolingual groups differed substantially in their identification performance, with English speakers tending to label most of them as /ba/ and Spanish speakers tending to label most of them as /pa/. The bilingual subjects heard the test stimuli in both an English and a Spanish context, each designed to induce a particular language ’’set.’’ These subjects perceived a reliably greater number of the test items as /ba/ in the English context than in the Spanish. The magnitude of this perceptual switching effect depends on the listener’s degree of bilingualism.