Objective: Assess hearing, tinnitus, and quality-of-life outcomes in adults with single-sided deafness (SSD) who underwent cochlear implantation.
Data Sources: PubMed, MEDLINE, Embase, Cochrane Central Register of Controlled Trials, Web of Science, and Scopus databases were searched from January 2008 to September 2021 following PRISMA guidelines.
Study Selection: Studies reporting hearing, tinnitus, and quality-of-life outcomes in adult patients (≥18 years old) with SSD were evaluated.
Data Extraction: Study characteristics, demographic data, hearing (speech recognition in quiet and noise, sound source localization), tinnitus, and quality-of-life outcomes were collected.
Data Synthesis: From an initial search of 1147 articles, 42 studies that evaluated cochlear implant (CI) use in 906 unique adults with SSD (50.6 ± 23.3 years age of implantation) were included. The mean duration of deafness was 6.3 ± 9.6 years. Most adults showed 43% (95% CI, 39.7 to 47.3, P< 0.001, CNC) to 48% (95% CI, 42.4 to 53.2, P< 0.001, AzBio) improvement in speech recognition in quiet and 19-24% (P <0.001) in noise with significant variation in target-to-masker configurations. Sound source localization, quantified as root-mean-squared error, improved with CI use (Mean difference [MD] -17.6º; 95% CI, -20.3º to -14.9º, P<0.001). Patients experienced a significant reduction in Tinnitus Handicap Inventory scores (MD -28.5; 95% CI -34.2 to -22.8, P<0.001) and improvements in Spatial, Speech, and Qualities of Hearing scores (MD 2.1; 95% CI, -1.7 to 2.5, P<0.001).
Conclusions: Cochlear implantation offers significant reduction in tinnitus severity and enhancement of speech recognition in quiet and noise, sound source localization, and perceived quality-of-life in adults with SSD.
*Professional Practice Gap & Educational Need: 1) Lack of comprehensive and up-to-date systematic review of the existing literature on outcomes of CI use in adults with SSD. 2) Most studies reporting outcomes of CI in SSD are nonrandomized trials with a small sample size which interferes with the generalizability of the data and recommendations. 3) Need for well-defined clinical guidelines.
*Learning Objective: 1) Attendees will understand the hearing benefits of cochlear implantation in adults with single sided deafness, particularly speech recognition in noise and sound localization. 2) Attendees will understand the benefits of cochlear implantation in improving tinnitus and quality of life associated with SSD.
*Desired Result: To conduct a systematic review of existing literature and perform a meta-analysis of the pooled data on outcomes of CI in SSD, particularly CI effect on speech recognition in noise, sound localization, tinnitus suppression, and improvement of quality of life.