Speech perception in visually impaired individuals might be diminished as a consequence of monomodal cue acquisition

Several studies suggest that both the auditory and the visual modalities are important for speech perception, while absence of the visual modality (e.g., due to visual impairment) causes perceptual deficits. By contrast, a body of research portrays that visual cues are not mandatory for the perception of speech movements and thus visually impaired individuals may demonstrate enhanced perceptual abilities. The present paper supports the hypothesis that second language speech perception in individuals with visual impairments might be diminished in comparison to speech perception in individuals with normal sight. Although there is evidence against this hypothesis, we assume that most of the earlier work did not take into account several factors which may affect speech perception, while research on second language phone perception by individuals with visual impairments is limited.