Long-Term Auditory, Tinnitus, and Psychological Outcomes After Cochlear Implantation in Single-Sided Deafness: A Two-Year Prospective Study.

Background/

Objectives

Single-sided deafness (SSD) impairs speech perception, reduces spatial hearing, decreases quality of life, and is frequently accompanied by tinnitus. Cochlear implantation (CI) has become an established treatment option, but long-term prospective evidence across multiple functional and psychological domains remains limited. This study investigated auditory performance, subjective hearing outcomes, tinnitus burden, and psychological well-being over a two-year follow-up in a large SSD cohort.

Methods

Seventy adults with SSD underwent unilateral CI. Assessments were conducted preoperatively and at 6 months, 1 year, and 2 years postoperatively. Outcome measures included the Freiburg Monosyllable Test (FS), Oldenburg Inventory (OI), Nijmegen Cochlear Implant Questionnaire (NCIQ), Tinnitus Questionnaire (TQ), Perceived Stress Questionnaire (PSQ), Generalized Anxiety Disorder scale (GAD-7), and General Depression Scale (ADS-L). Longitudinal changes were analyzed using Wilcoxon signed-rank tests with effect sizes; Holm-adjusted p-values were applied for baseline-to-follow-up comparisons.

Results

Speech perception improved markedly within the first 6 months and remained stable through 2 years, with large effect sizes. All OI subdomains demonstrated early and sustained improvements in subjective hearing ability. Several hearing-related quality-of-life domains assessed by the NCIQ, particularly social interaction, self-esteem, and activity participation, showed medium-to-large long-term improvements. Tinnitus severity decreased substantially, with marked reductions observed by 6 months and maintained thereafter; the proportion of tinnitus-free patients increased at follow-up, although tinnitus symptoms persisted in a substantial subset of participants. Perceived stress was reduced initially at the early follow-up and remained below baseline thereafter. Anxiety and depressive symptoms mostly stayed within nonclinical ranges, showing no lasting changes after adjusting for multiple comparisons.

Conclusions

In this prospective cohort, cochlear implantation was associated with durable improvements in auditory outcomes, tinnitus burden, and selected patient-reported quality-of-life domains over two years. Although significant functional and patient-centered improvements were noted, persistent tinnitus and diverse psychosocial outcomes underscore the need for personalized counseling and comprehensive follow-up that incorporate patient-reported outcomes and psychological assessments.