Contribution of articulatory kinematics to visual perception of stop consonants

Abstract

Little is known about visual cues that are critical to the accurate categorization, and perceived quality, of individual phonemes. The current study provided a preliminary evaluation of the relationship between orofacial movements and visual perception of phonemes distinguished by place of articulation. A female talker produced VCV utterances for /b/, /d/, and /g/ consonants; a natural range of variation was obtained by producing each consonant in several vowel contexts. Peak displacement, peak closing velocity, and peak opening velocity were measured from the upper lip, lower lip, and jaw. Observers identified place and rated the perceived quality, or goodness, of each token as an example of the consonant category (1=poor,7=good). As expected, observers identified bilabials with near-perfect accuracy, whereas they often confused alveolars and velars. More importantly, kinematic variation affected category goodness, particularly for /b/. Linear regression analyses indicated that goodness ratings within the /b/ category were highly correlated with lower lip and jaw displacement. In fact, articulatory displacement predicted these goodness ratings more effectively than did vowel context. Implications for understanding visual place cues are discussed. [Work supported by NICHD.]