Language Experience and Subjective Word Familiarity on the Multimodal Perception of Non-native Vowels

The present study investigated native (L1) and non-native (L2) speakers' perception of the French vowels /ɔ̃, ɑ̃, ɛ̃, o/. Thirty-four American-English learners of French and 33 native speakers of Parisian French were asked to identify 60 monosyllabic words produced by a native speaker in three modalities of presentation: auditory-only (A-only); audiovisual (AV); and visual-only (V-only). The L2 participants also completed a vocabulary knowledge test of the words presented in the perception experiment that aimed to explore whether subjective word familiarity affected speech perception. Results showed that overall performance was better in the AV and A-only conditions for the two groups with the pattern of confusion differing across modalities. The lack of audiovisual benefit was not due to the vowel contrasts being not visually salient enough, as shown by the native group's performance in the V-only modality, but to the L2 group's weaker sensitivity to visual information. Additionally, a significant relationship was found between subjective word familiarity and AV and A-only (but not V-only) perception of non-native contrasts.