Visual information affects adaptation to novel talkers: Ethnicity-specific and ethnicity-independent learning of L2-accented speech.

Prior work demonstrates that exposure to speakers of the same accent facilitates comprehension of a novel talker with the same accent (accent-specific learning). Moreover, exposure to speakers of multiple different accents enhances understanding of a talker with a novel accent (accent-independent learning). Although bottom-up acoustic information about accent constrains adaptation to novel talkers, the effect of top-down social information remains unclear. The current study examined effects of apparent ethnicity on adaptation to novel L2-accented ("non-native") talkers while keeping bottom-up information constant. Native English listeners transcribed sentences in noise for three Mandarin-accented English speakers and then a fourth (novel) Mandarin-accented English speaker. Transcription accuracy of the novel talker improves when: all speakers are presented with east Asian faces (ethnicity-specific learning); the exposure speakers are paired with different, non-east Asian ethnicities and the novel talker has an east Asian face (ethnicity-independent learning). However, accuracy does not improve when all speakers have White faces or when the exposure speakers have White faces and the test talker has an east Asian face. This study demonstrates that apparent ethnicity affects adaptation to novel L2-accented talkers, thus underscoring the importance of social expectations in perceptual learning and cross-talker generalization.