A multicenter phase III RCT of 213 patients with idiopathic sudden sensorineural hearing loss (ISSHL) and tinnitus found no benefit from acoustic therapy during the acute 10-day hospitalization period, regardless of whether steroid therapy was combined with batroxobin. However, patients with severe ISSHL who continued home-based sound therapy for 6 months experienced substantially higher tinnitus remission rates (45.5% vs 20%). This effect did not extend to patients with mild or moderate hearing loss.

The study suggests that extended, frequency-matched sound therapy may support neural adaptation in patients with large cochlear deficits, while the short-term inpatient regimen appears ineffective. Despite limitations—chiefly inadequate sample size—the safety profile was favorable, and the findings highlight a potential therapeutic window for severe ISSHL–related tinnitus that warrants targeted, well-powered follow-up trials.