Abstract:

Two groups of Japanese speakers were trained to identify AE /r/ and /l/ using two different types of training: audio visual and auditory only. In audiovisual training, a movie of the talker's face was presented together with the auditory stimuli, whereas only auditory stimuli were presented in audio-only training. Improvement in /r/--/l/ identification from pretest to post-test on three types of tests (audio-only, visual only and audiovisual) did not differ substantially across the two training groups. Interestingly, the audio-only group showed improved identification in the visual-only tests, suggesting that training in the auditory domain transferred to the visual domain. A McGurk-type test using /r/ and /l/ stimuli with conflicting audio and visual information was also conducted. Identification accuracies on this test showed a greater effect of conflicting visual information at post-test than at pretest for the audio--visual training group, but not for the audio-only training group, suggesting that audio-visual training facilitated integration of auditory and visual information. Taken together, these results suggest that the internal representation of second-language phonetic categories incorporates both auditory and visual information. Implications for theories of perceptual learning and phonological development will be discussed.