The Use of Auditory and Visual Information in Phonetic Perception

Abstract

Although speech perception is usually considered an auditory process, studies have shown that visual information provided by the movements of a talker’s mouth and face strongly influences what an observer perceives even when the auditory signal is clear and unambiguous. The now classic “McGurk effect” is an excellent example: the auditory syllable /bi/ presented in synchrony with a videotape of a talker saying the syllable /gi/ is usually perceived as /di/, a syllable not presented to either modality. This phenomenon has important implications for theories of speech perception which must account for how and why auditory and visual signals are integrated during phonetic processing. The purpose of the current talk is to describe some of the research that has contributed to our understanding of how visual and auditory information are used in phonetic perception. Specifically, this paper focuses on three issues: (1) what factors influence the integration of auditory and visual information; (2) the nature of the auditory and visual information used in phonetic perception; and (3) the interaction of the two sources of information during phonetic processing. The implications of these findings for theories of speech perception are discussed.