Objective: The heterogeneity of tinnitus perception and its impact necessitates a tailor-made management approach in each individual. The current study examined the effects of residual inhibition in combined amplification and sound therapy in individuals with tinnitus and co-existing hearing loss.
Materials and methods: A retrospective analysis was performed on patients with tinnitus and co-existing hearing loss between 2016 and 2019. A total of 72 patients provided with combined amplification and sound therapy were divided into 3 groups based on residual inhibition (RI): (i) complete RI, (ii) Partial RI, and (iii) negative RI. Tinnitus severity was measured using the Tinnitus Functional Index (TFI) before treatment, and 1 and 6 months after the intervention. A multi-level mixed-effect model was used to examine the treatment effects including both the main and interaction effects of time and RI on the tinnitus severity.
Results: Of the 72 participants, 55 (76%) and 61 (85%) had clinically significant change (13-points in TFI) at 1-month and 6-months post-intervention, respectively. In the complete, partial, and negative RI group, the reduction in tinnitus impact was 100%, 78%, and 74%, respectively. A multi-level mixed model analysis showed that the main effects of time and RI along with their interaction were significant.
Conclusions: The study results suggest that combined amplification and sound therapy is beneficial in individuals with tinnitus and co-existing hearing loss in reducing their tinnitus severity, and this benefit was more in individuals with complete RI. However, these results need to be further confirmed by controlled trials.