To develop an evidence-based technique for providing recommendations to candidates for cochlear implantation with significant residual hearing and to assess the efficacy of the approach.
Modified selection criteria were derived from an analysis of the postoperative performance for a large group of adult cochlear implant users. In particular, the distributions of results for implant users with significant preoperative open-set speech perception were reviewed. This suggested that the candidates had a good chance (>75%) of overall improvement if they obtained open-set sentence scores in quiet of up to 70% in the best-aided condition and scores of up to 40% in the ear to undergo implantation.
A group of 45 adult implantation candidates who fit the modified criteria and who underwent preimplantation and postimplantation assessment to compare actual results with those predicted from the distributions.
The speech perception results showed that 36 subjects (80%) had improved open-set sentence scores with the cochlear implant compared with their best-aided preoperative performance (mean improvement, 20.5%). Forty-four (98%) had improved open-set sentence scores for the ear undergoing implantation (mean improvement, 65.3%).
The general concept of using the distribution of speech perception results to make evidence-based recommendations for candidates for cochlear implants is supported by this study. The approach can be used across different subpopulations, including older children with significant residual auditory skills, and for different outcome measures. It is important that the data used to provide recommendations and modify selection criteria are from an unselected sample of implant users of adequate size. This study highlights the continuing need to evaluate speech perception performance carefully before and after cochlear implantation.