Influence of native language phonetic system on audio-visual speech perception

This study examines how native language (L1) experience affects auditory–visual (AV) perception of nonnative (L2) speech. Korean, Mandarin and English perceivers were presented with English CV syllables containing fricatives with three places of articulation: labiodentals nonexistent in Korean, interdentals nonexistent in Korean and Mandarin, and alveolars occurring in all three L1s. The stimuli were presented as auditory-only, visual-only, congruent AV and incongruent AV. Results show that for the labiodentals which are nonnative in Korean, the Koreans had lower accuracy for the visual domain than the English and the Mandarin perceivers, but they nevertheless achieved native-level perception in the auditory and AV domains. For the interdentals nonexistent in Korean and Mandarin, while both nonnative groups had lower accuracy in the auditory domain than the native English group, they benefited from the visual information with improved performance in AV perception. Comparing the two nonnative groups, the Mandarin perceivers showed poorer auditory and AV identification for the interdentals and greater AV-fusion with the incongruent AV material than did the Koreans. These results indicate that nonnative perceivers are able to use visual speech information in L2 perception, although acquiring accurate use of the auditory and visual domains may not be similarly achieved across native groups, a process influenced by L1 experience.