Visual cue salience depends on place of articulation and syllabic context

Abstract

This study is on audio-visual perceptual intelligibility of consonants in intervocalic clusters (VC1C2V). Previous studies have yielded inconsistent findings on perceptual salience of different stop consonants and very few have tested salience in clusters. Consequently, it has been unclear as to whether greater or less perceptual salience leads to greater degree of place assimilation. In Korean, labials are often produced with more gestural overlap than velars in C1. I tested whether labials are perceptually more or less salient in both audio and audio-visual conditions. VC and CV syllables spoken by both English and Korean speakers were first embedded in noise and spliced together for non-overlapping VCCV sequences. Korean listeners identified the two consonants in either audio or AV presentations. A confusion matrix analysis for each stop consonant shows that in C1 there is asymmetric improvement with the addition of videos for labial consonants only, while in C2 this asymmetry was not found. The result suggests that listeners make differential use of visual cues depending on place of articulation and syllabic context. Also, the result supports the talker enhancement view of sound change, which assumes that talkers are aware of perceptual salience and enhance (with less gestural overlap) the weak contrast.