Dominance, mode, and individual variation in bilingual speech production and perception

Early Spanish-English bilinguals and English controls were tested on the production and perception of negative, short-lag, and long-lag Voice Onset Time (VOT). These VOT types span Spanish and English phonetic categories. Phonologically, negative and short-lag VOT stops are distinct phonemes in Spanish, while both are realizations of voiced stops in English. Dominance was critical: more English-dominant bilinguals produced more short-lag VOT stops in response to negative VOT stimuli, and were less accurate than more balanced bilinguals at discriminating negative from short-lag VOT. Bilinguals performed similarly to monolinguals overall, but they produced more negative VOT tokens and shorter short-lag VOT in response to negative VOT. Their productions were also less well correlated with perception and showed more variation between individuals. These results highlight the variable nature of bilingual production and perception, and demonstrate the need to consider language dominance, individual variation, as well as modalities and tasks when studying bilinguals.