The study examined the phonological processing skills in a group of adults who have acquired a severe hearing loss in adult life. These severely hearing-impaired individuals performed at a significantly lower level on the rhyme judgement tasks and the letter span task, but on a par with the control group on other cognitive tests. A correlation analysis showed that duration of hearing loss is negatively related to performance on the rhyme judgement tasks and letter span task. The results indicate that the phonological processing skills in individuals who have acquired a severe hearing loss in adult life deteriorates. The results are discussed with respect to theoretical and clinical implications.

Phonological processing was examined in a group of individuals with an acquired severe hearing loss and compared to a group of matched normal hearing individuals. The hearing-impaired group was significantly slower and less accurate when performing a visual rhyme-judgement task, and produced fewer rhyming word pairs on a rhyme-generation task than the normal hearing group. In contrast, the hearing-impaired group performed on a par with the normal hearing group on verbal working memory tasks. It is concluded that specific aspects of the phonological system deteriorate in this population as a function of auditory deprivation. In particular, the phonological representations are impaired and this impairment also affects the ability to rapidly perform phonological operations (i.e., analyse and compare). In contrast, phonological processing involved in verbal working memory is preserved in this population.

In the present study cognitive performance in 15 deafened adult cochlear implant candidates was examined and related to level of speech understanding after 12 months of experience with the implant. The implant group performed on par with normal hearing controls in all cognitive tasks used in the study with one exception: Performance was significantly lower in cognitive tasks where use of a phonological representation of sound is a key task-demand. Observations of the implanted individuals' level of speech understanding indicate that only those individuals who, pre-operatively, were in possession of phonological representations comparable to that of normal hearing could follow and understand a speaker that was out of sight. The results are discussed with respect to (a) deterioration in the phonological representation of sounds as a function of absence of external auditory stimulation, and (b) the role of cognitive factors in predicting success in speech understanding with the implant.

This study examined the extent to which different measures ofspeechreading performance correlated with particular cognitiveabilities in a population of hearing-impaired people. Althoughthe three speechreading tasks (isolated word identification,sentence comprehension, and text tracking) were highly intercorrelated,they tapped different cognitive skills. In this population,younger participants were better speechreaders, and, when agewas taken into account, speech tracking correlated primarilywith (written) lexical decision speed. In contrast, speechreadingfor sentence comprehension correlated most strongly with performanceon a phonological processing task (written pseudohomophone detection)but also on a span measure that may have utilized visual, nonverbalmemory for letters. We discuss the implications of this pattern.