Auditory-Visual Speech Perception as a Direct Process: The McGurk Effect in Infants and Across Languages

Abstract

The McGurk effect, in which auditory [b] dubbed onto visual [g] is perceived as [d] or [D] (as in them), is used in two experiments on humans’ integration of auditory and visual speech information. In the first it was found that 4-month-old infants perceive the McGurk effect. In the second a group of English- and another of Thai-speaking adults were tested on the auditory [m] plus visual [N] (=[n]) version of the effect. Despite the phonological irrelevance of initial [N] in English, both groups perceived a [na] fusion to the same extent. Thus the McGurk effect transcends phonological constraints. The results suggest that auditory and visual speech information is integrated in a common metric which is unaffected by phonological experience.