The influence of age at implantation on performance with a cochlear implant in children

Abstract

Objective: This study involved the assessment of speech recognition abilities as a function of age at implantation and length of cochlear implant use in children who received the Nucleus CI22M cochlear implant.

Study design: Two separate analyses were performed. The first analysis involved the assessment of speech recognition performance as a function of length of time with a cochlear implant in 48 patients evaluated at 7 years of age. The second analysis involved the assessment of speech recognition performance as a function of age at implantation in 53 patients evaluated 36 months after implantation. Patients were divided into four groups based on length of implant use or age at implantation, and the results were analyzed by a repeated-measures analysis of variance.

Setting: This study was carried out at a tertiary academic medical center.

Patients: Patients consisted of children implanted with a Nucleus Multi Channel cochlear implant programmed with the SPEAK encoding strategy. Their ages at the time of evaluation ranged from 5.5 to 7.8 years. Their ages at implantation ranged from 2.4 to 14.5 years.

Interventions: All patients received a Nucleus Multi Channel cochlear implant programmed with the SPEAK encoding strategy. Word and sentence recognition tests were administered at various ages and at several postimplantation intervals.

Main outcome measures: Performance as a function of length of cochlear implant use and as a function of age at implantation.

Results: Patients performed significantly better as length of cochlear implant use increased and age at implantation decreased. When patients were tested at a fixed postimplantation time interval (36 months), there was an overall trend for patients who received the implant at a younger age to perform better in spite of being younger at the time of evaluation. However, these effects were not statistically significant for all speech recognition tests that were administered.

Conclusions: These results confirm previous findings indicating continued improvement of speech recognition with time in implanted children. Furthermore, the results support the concept of the advantage of a younger age at implantation.