# Efficacy and safety of a modified sound therapy for patients with subjective tinnitus (MOST): a multicentre, double-blind, randomised controlled trial

## TL;DR

A study tested sound therapies for tinnitus and found that a personalized sound therapy showed the most improvement in tinnitus severity over nine months.

## Contribution

The study introduces a modified digital frequency-customised relieving sound therapy as a promising treatment for chronic tinnitus.

## Key findings

- Digital frequency-customised relieving sound (DFCRS) showed superior efficacy compared to unmodified music.
- Tinnitus severity significantly decreased over time in all groups, with effects sustained posttreatment.
- Only one participant achieved complete remission, highlighting the need for further refinement of treatment methods.

## Abstract

Tinnitus is a common and often debilitating auditory condition with limited treatment options. While sound therapy is widely used, robust evidence from long-term randomised trials is scarce. We aimed to evaluate the 9-month efficacy and 3-month posttreatment durability of four sound therapies for adults with chronic subjective tinnitus and identify predictors of response.

In this multicentre, double-blind, randomised controlled clinical trial, participants (aged 18–80 years) with chronic subjective tinnitus from three academic hospitals in China were included. Participants were randomly 1:1:1:1 assigned to receive one of four daily 2-h interventions: unmodified music (UM), UM plus pitch-centered narrowband noise (UM + NBN), high-frequency–enhanced music (HFEM), or digital frequency-customised relieving sound (DFCRS). Primary outcome was tinnitus severity assessed by Tinnitus Handicap Inventory (THI). Assessments occurred at baseline, 1, 2, 3, 6, and 9 months, with a 3-month posttreatment follow-up. Two prespecified primary endpoints were defined: (a) complete remission, operationalised as a THI score of 0 at any follow-up visit within the 9-month period. Participants achieving this endpoint were considered clinically cured, and sound therapy was discontinued; or (b) if complete remission was not achieved by the end of 9 months, the magnitude of improvement was defined as the change in THI score from baseline to the 9-month endpoint. The primary analysis followed the intention-to-treat (ITT) principle, This trial is registered with the Chinese Clinical Trial Registry, ChiCTR2000039007.

Between May 14, 2021, and November 30, 2022, 440 participants (median age 45 years [IQR, 35–56]; 222/440 [50·5%] male; median tinnitus duration 13 months [IQR, 7–36]) were enrolled and randomly assigned (UM, n = 111; UM + NBN, n = 110; HFEM, n = 108; DFCRS, n = 111). Baseline characteristics were balanced between the groups. Only one participant in the HFEM group achieved complete remission, with a THI score of 0 at the 6-month follow-up. THI scores significantly decreased over time in all groups (median 50·00 [IQR 36·00–62·00]) at baseline to 9-month follow-up (35·00 [24·00–48·00]; p < 0·0001), with effects sustained posttreatment. Significant group × time interactions occurred (UM: F(5, 618) = 11·45; UM + NBN: F(5, 605) = 7·17; HFEM: F(5, 599) = 8·3; DFCRS: F(5, 619) = 12·65; all p < 0·0001) in all arms. DFCRS demonstrated superior efficacy (parameter estimate −4·37, 95% CI −6·25 to −2·48; p < 0·0001), when compared to UM as reference. No adverse events were reported in any group.

In this exploratory trial, personalised acoustic therapy may provide promising efficacy for chronic tinnitus. Although interpretation is tempered by the absence of a blank control arm and objective adherence monitoring, these limitations highlight opportunities for future studies to refine methods and validate treatment benefits more robustly.

The Ministry of Science and Technology, the Shanghai Shenkang Development Centre, the 10.13039/501100003399Shanghai Science and Technology Committee, and the 10.13039/501100001809National Natural Science Foundation of China.