The impact of cochlear implantation on phonological awareness in deaf children
In recent years, it has been reported that cochlear implantation (CI) benefits deaf children's speech perception, language development and speech production. Early fitting of an implant results in improved outcomes. This thesis explores the development and determinants of phonological awareness (PA) in paediatric Cl users. Phonological awareness is important for literacy acquisition in hearing children. In hearing children phonological awareness develops first at the syllable level then at the intra-syllabic level of onset-rime and finally at the phoneme level. It is expected that paediatric Cl users will follow the same developmental trajectory. The impact of the timing of cochlear implant fitting on phonological awareness and the relationship between phonological awareness and word reading are also investigated. Three new tests of phonological awareness were developed for the thesis. Nineteen children with implants were seen twice over a 12 month period. Nine of these children were fitted with their implant early (below 3.6 years) and ten were fitted later (between 5 and 7 years). Several comparison groups were included; a group of profoundly deaf children with hearing aids, a group of severely deaf children, a group of hearing children with specific language impairment and two groups of typically developing hearing children. One hearing group was matched for reading level and the other group was matched for chronological age to the Cl group. Phonological awareness in Cl users developed along a similar trajectory to hearing children. Syllable awareness was equivalent in the Cl group to both groups of hearing children, awareness of rhyme and phonemes was significantly delayed, but was equivalent to the profoundly deaf children using hearing aids. The difference between the early and late Cl groups on PA performance was small. There was some evidence of a link between PA and word reading, but overall, receptive vocabulary emerged as the most robust longitudinal predictor of reading ability in deaf children.