Objective: This study aimed to evaluate the long-term speech intelligibility of young deaf children after cochlear implantation.
Study Design: The study design was a prospective study following a large group of consecutively implanted deaf children with up to 5 years' cochlear implant use.
Setting: The study was conducted at a pediatric tertiary referal center for cochlear implantation.
Patients: All children in the study were congenitally deaf or deafened before 3 years of age. They each received a Nucleus multichannel cochlear implant before the age of 7 years. Eighty-four subjects were evaluated up to 5 years after cochlear implantation.
Intervention: Cochlear implantation followed by an internsive program of local and center-based assessment and rehabilitation was performed.
Main Outcome Measures: A speech intelligibility rating scale evaluated the spontaneous speech of each child before and at yearly intervals for 5 years after implantation.
Results: After cochlear implantation, the difference between the speech intelligibility ratings increased significantly each year for 4 years (Mann-Whitney U-test). For the first 2 years, the average rating remained “prerecognizable words‘’ or “unintelligible speech.‘’ It was not until the 3-year interval that the average intelligibility rating became category 3 (intelligible speech If someone concentrates and lip-reads). At the 4-year interval, 85% of children had some intelligible connected speech. This improvement continued, and at the 5-year interval, the median speech intelligibility was category 4 (intelligible speech to a listener with a little experience of deaf speech) and the mode was category 5 (intelligible speech to all listeners).
Conclusion: Congenital and prelingually deaf children gradually develop intelligible speech that does not plateau 5 years after implantation.