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.