Speech development and auditory performance in children after cochlear implantation

Background: The aim of this study was to determine the auditory performance of congenitally deaf children and the effect of cochlear implantation (CI) on speech intelligibility. Methods: A prospective study was undertaken on 47 children in a pediatric tertiary referral center for CI. All children were deaf prelingually and were younger than 8 years of age. They were followed up until 5 years after implantation. Auditory performance was assessed by using the categories of auditory performance (CAP) scale and speech intelligibility rating which evaluated the spontaneous speech of each child before and at frequent intervals for five years after implantation. Results: Pre-lingually deaf children showed significant improvement in auditory performance after implantation. Six months after implantation 91% of children had the ability to respond to speech sounds. At the end of year one, 96% of children could discriminate speech sounds and 84% of children who reached the three year interval could understand common phrases without lip-reading. After cochlear implantation, the difference between the speech intelligibility rating increased significantly each year for 3 years (p<0.05) and did not plateau up to 5 years after implantation. The changes in auditory performance and speech development were parallel. Conclusion: The results indicated the ability of cochlear implantations to significantly improve auditory receptive skills and subsequently speech development in young congenitally deaf children.