Benefits of unilateral cochlear implantation in adults with asymmetric hearing loss: Audiologic and patient-related outcome measures

Purpose: To investigate the benefits of cochlear implantation in adults with single-sided deafness (SSD) and asymmetric hearing loss (AHL).Study design: Prospective within-subjects repeated-measures.Setting: Two tertiary cochlear implant centers.Patients: Fourteen adults with severe-to-profound sensorineural hearing loss in the worse hearing ear and up to moderate SNHL in the better hearing ear.Intervention: Cochlear implantation in the worse hearing ear.Main outcome measures: Consonant-nucleus-consonant (CNC) test, AzBio sentence test in noise, and lateralization testing were conducted preoperatively and at 3-, 6-, and 12-months post-activation. Patient-related outcomes were measured using the Speech, Spatial, and Qualities of Hearing Scale and Glasgow Benefit Inventory. Tinnitus Handicap Inventory was administered to subjects with tinnitus.Results: Mean length of hearing loss in the worse hearing ear was 3.5 years. The mean CNC change scores from baseline were 54.8, 55.9, and 58.9 percentage points at 3-, 6-, and 12-months (p < 0.001). AzBio sentence test in noise demonstrated improved scores in all spatial configurations, although statistically significant in S0N0 (speech front, noise front) only. Lateralization testing showed significant improvement of 22.9, 24.5, and 24.0 percentage points at 3-, 6-, and 12 months post-activation (p = 0.002). All patient-related outcome measures revealed significant improvement.Conclusion: This study demonstrates improved speech perception in noise, sound lateralization, quality of life, and reduction in tinnitus perception in adults with SSD/AHL who undergo cochlear implantation. Our results add to the growing body of evidence that cochlear implant should be offered to this population.