Beyond lips : components of speechreading skill

The purpose of the present thesis was threefold. First, to study perceptual and cognitive correlates to individual differences in speechreading performance. Second, to examine certain aspects of word-decoding/discrimination in the speechreading process. Third, to investigate whether hearing-impaired individuals compensate for their hearing loss by means of improved speechreading ability. The results demonstrate that individual differences on a set of perceptual and cognitive component processes were related to speechreading either directly or indirectly, and could also be classified as influencing speechreading generally or specifically. Based on this 2 by 2 taxonomy, it was thus possible to establish which kind of relationship and what kind of effect a certain cognitive component is responsible for in speechreading. The results also indicate that there are similarities between visual and auditory speech perception in the temporal order that words are recognized. A process model for speechreading was also developed and further test implications were delineated. The results do not indicate that hearing-impaired individuals compensate for their hearing loss by means of an improved speechreading ability, neither do they rely on a different set of cognitive components for successful speechreading.