Evidence-Based Recommendation for Bilateral Cochlear Implantation in Adults

Purpose Most adult cochlear implant (CI) users in developed countries benefit from the use of a hearing aid in conjunction with their implant device (bimodal hearing). Benefits have also been documented for the use of bilateral CIs for speech perception in quiet, localization, and speech perception in noise. This study attempted to quantify speech perception results for bimodal and bilateral CIs in adults and provide a guide for those considering a 2nd CI. Method Speech perception outcomes were reviewed for 1,394 adults with acquired hearing loss who received a CI at the Melbourne Cochlear Implant Clinic between 2000 and 2015. Results Bimodal and bilateral users significantly outperformed unilateral CI users on consonant-vowel-consonant word recognition in quiet. For the bilateral group, word recognition scores with the 1st CI were predictive of 2nd CI word scores. The analysis suggested that bimodal users who were gaining less than 19% benefit from the nonimplanted ear were likely to perform better with a 2nd implant. Conclusions CI users who score less than 19% on consonant-vowel-consonant words in the nonimplanted ear have a good chance of benefiting from a 2nd implant. Consideration of many other factors including age, hearing goals, medical factors, and the risk to residual hearing also needs to play a part in recommending a 2nd CI.