Objective: This study aimed to determine the speech perception ability of congenitally and prelingually deaf children after cochlear implantation.
Study Design: 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.
Methods: 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.
Setting: The study was conducted at a tertiary referral pediatric cochlear implant center in the United Kingdom.
Results: 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.
Conclusion: 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.