The effect of facial musculature on cross modal perception

Abstract

Speech processing has been shown as a cross modal interaction of different sensory systems. The present study explored cross modal perceptions in speech, particularly facial musculature in vowel categorization, discrimination and audiovisual processing. The study hypothesized that facial musculature congruence would bias perception of speech towards assigned lip condition and thus influencing speech perception. The study used a between-subjects design (Lip-rounding x Lip-spreading x Neutral Lip) with 60 participants. Participants were given audio identity tasks, audio discrimination tasks and audiovisual tasks to investigate individual components of speech perception. The purpose of the study was masked using a cover story. This study found significant cross modal interaction between facial musculature and perception of speech and explained observed results referencing to the facial feedback hypothesis and motor theory of speech. These findings suggest facial musculature influences speech perception at a subconscious level. Limitations and implications to future research were also discussed.