Response to Audiovisual Nonnative Phonemic Contrasts Does Not Decline in Infancy

Previous research has demonstrated that sensitivity to unimodal nonnative speech
contrasts generally narrows during the first year. Although other work has demonstrated
a processing advantage for multimodal stimuli, research on infants' responsiveness to
nonnative contrasts so far has not examined whether concurrent auditory and visual
speech information can modulate perceptual narrowing. Thus, the current study
investigated the influence ofbimodally specified speech sounds on infants' sensitivity to
a nonnative phonemic contrast. Six-month-old and 10- to 12-month-old infants were
tested in a habituation/test procedure for discrimination of an audiovisual nonnative
speech contrast (Hindi /tal dental vs. /Tal retroflex stop). Findings showed that infants at
both ages exhibited evidence of discrimination following habituation to one of the speech
sounds. These findings suggest that the usually observed decline in responsiveness to
nonnative speech contrasts is limited to audibly specified contrasts and that concurrent
visual speech information enhances the discriminability of such contrasts.