To study the effects of age at implantation and duration of implant use on the performance of spoken word recognition of pediatric cochlear implantees in a tonal language setting over a period of 5 years.
Sixty-four children, given implants between the ages 1:01 and 14:09 (years:months), were divided into three age groups. They were tested on open-set word recognition ability at seven time intervals from before surgery to 5 years after surgery. Analyses of variance with repeated measurements were used to examine the effect of their age at implantation and the duration of implant use.
Duration of implant experience was significant in spoken word recognition across the three age groups (p < 0.01). Children given implants below the age of 3 years caught up with the performance of the older children at 12 months after implantation. The difference in score reached statistical significance at 2 and at 3 years after surgery (p = 0.03, p = 0.00).
The performance of Cantonese-speaking children was similar to that of English-speaking children in that better outcomes were associated with longer implant experience as well as when implantation occurred at a younger age. The children implanted before the age of 3 and who had an implant experience of more than 2 years outperformed the children who were given implants after the age of 6 and also sustained these higher scores throughout 5 years of postimplant testing.
This study investigated the effects of age at implantation and duration of implant use on the performance of spoken word recognition on 64 Cantonese-speaking cochlear implant children over a period of five years. Continuous improvement was noted in all children in the five-year period irrespective of their age at implantation. Children implanted before the age of three improved at a slower rate before one full year of implant use. By two years of implant use, the performance of the young children outperformed the children who were implanted after the age of six, and also sustained these higher scores throughout five years of post-implant testing. The findings suggest that Cantonese- speaking children performed in a similar way to their English-speaking counterparts in that better word recognition outcomes were associated with longer implant experience and an earlier age of implantation.
The Institute of Human Communicative Research, The Chinese University of Hong Kong, SAR.
Address for correspondence: Kathy Yuet Sheung Lee, Ph.D., Division of Otorhinolaryngology, Department of Surgery, The Chinese University of Hong Kong, Prince of Wales Hospital, Shatin, Hong Kong, SAR.
Received October 15, 2004; accepted March 29, 2005