Phonological capacities in deafened adults and individuals with a severe hearing-loss: Some functional consequences

In the present paper we will give an overview of a number of studies where the purpose has been to examine deafened adults ́ phonological representation of sounds and possible functional consequences of an imperfect phonological representation. Deafened adults ́ performance on cognitive tasks that require phonological processing has been compared with that of normal hearing individuals. The results indicate that the phonological representation in deafened adults deteriorates as a function of absence of external auditory stimulation. The magnitude of the deterioration is further correlated with duration of deafness, where long duration leads to poorer performance. The quality of the deafened adults ́ phonological representation is related to performance in communicative tasks such as visual speechreading, tactile supported speechreading and speech understanding with cochlear implants. The results will be discussed with respect to (a) what factors that cause the deterioration in the phonological representation and (b) what kind of role a phonological representation serves in speech understanding for this group of individuals.