Reconsidering Cochlear Implant Candidacy in Asymmetric Hearing Loss: A Scoping Review of Functional and Quality-of-Life Gains.

BACKGROUND

Asymmetric hearing loss (AHL)-defined as severe-to-profound hearing loss in one ear with better hearing in the other-can significantly impair communication and quality of life (QoL). Although cochlear implantation (CI) is an established treatment for sensorineural hearing loss, restrictive FDA and Medicare criteria often exclude AHL patients who could benefit. Emerging evidence suggests CI improves auditory function and QoL in this population.

OBJECTIVES

Perform a scoping review of the literature on CI in adults with AHL, focusing on audiometric and QoL outcomes.

METHODS

A scoping review was conducted per PRISMA guidelines. Databases searched included Ovid MEDLINE, Embase, CENTRAL, CINAHL, and Web of Science. Eligible studies involved adult AHL patients undergoing CI reporting preoperative and postoperative audiometric or QoL data. Two reviewers independently screened and extracted data.

RESULTS

Twenty-five studies met inclusion criteria, reporting 23 audiometric and 21 different QoL measures. The Consonant-Nucleus-Consonant (CNC) test was the most used, with average preoperative scores in the implanted ear ranging from 3.6% to 18.3% to 49.3% to 66.2% at 12 months. Sentence recognition in quiet (AzBio) increased from 13% to 25% preoperatively to as high as 84% bimodally. In noise (+5dB SNR), bimodal AzBio scores rose from 27% to 30% preoperatively to 49% to 68% at 6 months, with sustained 12-month benefit. QoL measures-including the Speech, Spatial and Qualities of Hearing Scale (SSQ) and Nijmegen Cochlear Implant Questionnaire (NCIQ)-showed significant improvements in 92% and 100% of studies, respectively.

CONCLUSIONS

CI provides substantial auditory and QoL benefits for adults with AHL, supporting reconsideration of candidacy criteria to expand access.