This study examines how visual speech information affects native judgments of the intelligibility of speech sounds produced by non-native (L2) speakers. Native Canadian English perceivers as judges perceived three English phonemic contrasts (/b-v, θ-s, l-É1;/) produced by native Japanese speakers as well as native Canadian English speakers as controls. These stimuli were presented under audio-visual (AV, with speaker voice and face), audio-only (AO), and visual-only (VO) conditions. The results showed that, across conditions, the overall intelligibility of Japanese productions of the native (Japanese)-like phonemes (/b, s, l/) was significantly higher than the non-Japanese phonemes (/v, θ, É1;/). In terms of visual effects, the more visually salient non-Japanese phonemes /v, θ/ were perceived as significantly more intelligible when presented in the AV compared to the AO condition, indicating enhanced intelligibility when visual speech information is available. However, the non-Japanese phoneme /É1;/ was perceived as less intelligible in the AV compared to the AO condition. Further analysis revealed that, unlike the native English productions, the Japanese speakers produced /É1;/ without visible lip-rounding, indicating that non-native speakers' incorrect articulatory configurations may decrease the degree of intelligibility. These results suggest that visual speech information may either positively or negatively affect L2 speech intelligibility.
|Number of pages||11|
|Journal||Journal of the Acoustical Society of America|
|Publication status||Published - 2014 Sept 1|
ASJC Scopus subject areas
- Arts and Humanities (miscellaneous)
- Acoustics and Ultrasonics