Speech perception in children after cochlear implantation

This study aimed to determine the speech perception ability of congenitally and prelingually deaf children after cochlear implantation.

A prospective study was undertaken on a consecutive group of 119 congenitally and prelingually deaf children up to 5 years after implantation. The study group was confined to children between 2 and 7 years of age at the time of implantation. All were implanted with multichannel cochlear implant systems. No child was lost to follow-up, and there were no exclusions from the study other than one child with auditory nerve aplasia.

The Iowa Matrix Closed Set Sentence Test and Connected Discourse Tracking were used to assess closed- and open-set speech perception, respectively, without lip reading.

The study was conducted at a tertiary referral pediatric cochlear implant center in the United Kingdom.

It was possible to formally test closed-set speech discrimination on 83, 55, 32, 21, and 15 children at 12, 24, 36, 48, and 60 months, respectively. On the Iowa Matrix Test, the median score was 0% at 12 months, reaching a plateau of 99% at 36 months. On Connected Discourse Tracking, the median scores at 12, 24, 36, 48, and 60 months were 0, 0, 21, 40, and 53 words per minute, respectively.

Congenitally and prelingually deaf children who receive cochlear implants before the age of 7 years have significant closed-set speech perception abilities develop in <3 years after implantation. Their ability to perform open-set tasks without lip reading is limited in the first 2 years but shows significant improvement, not reaching a plateau, at the 4-5-year interval after implantation.