Speech production intelligibility of early implanted pediatric cochlear implant users

To investigate the influence of age, and age-at-implantation, on speech production intelligibility in prelingually deaf pediatric cochlear implant recipients.

Forty prelingually, profoundly deaf children who received cochlear implants between 8 and 40 months of age. Their age at testing ranged between 2.5 and 18 years. Children were recorded repeating the 10 sentences in the Beginner's Intelligibility Test. These recordings were played back to normal-hearing listeners who were unfamiliar with deaf speech and who were instructed to write down what they heard. They also rated each subject for the intelligibility of their speech production on a 5-point rating-scale. The main outcome measures were the percentage of target words correctly transcribed, and the intelligibility ratings, in both cases averaged across 3 normal-hearing listeners.

The data showed a strong effect of age at testing, with older children being more intelligible. This effect was particularly pronounced for children implanted in the first 24 months of life, all of whom had speech production intelligibility scores of 80% or higher when they were tested at age 5.5 years or older. This was true for only 5 out of 9 children implanted at age 25-36 months.

Profoundly deaf children who receive cochlear implants in the first 2 years of life produce highly intelligible speech before the age of 6. This is also true for most, but not all children implanted in their third year.