Linguistic experience and audio-visual perception of non-native fricatives

This study examined the effects of linguistic experience on audio-visual (AV) perception of non-native (L2) speech. Canadian English natives and Mandarin Chinese natives differing in degree of English exposure [long and short length of residence (LOR) in Canada] were presented with English fricatives of three visually distinct places of articulation: interdentals nonexistent in Mandarin and labiodentals and alveolars common in both languages. Stimuli were presented in quiet and in a café-noise background in four ways: audio only (A), visual only (V), congruent AV (AVc), and incongruent AV (AVi). Identification results showed that overall performance was better in the AVc than in the A or V condition and better in quiet than in café noise. While the Mandarin long LOR group approximated the native English patterns, the short LOR group showed poorer interdental identification, more reliance on visual information, and greater AV-fusion with the AVi materials, indicating the failure of L2 visual speech category formation with the short LOR non-natives and the positive effects of linguistic experience with the long LOR non-natives. These results point to an integrated network in AV speech processing as a function of linguistic background and provide evidence to extend auditory-based L2 speech learning theories to the visual domain