Sound enrichment therapy is more effective for long-term tinnitus suppression with 10 Hz amplitude modulation

Tinnitus is a complex clinical condition that lacks a well-established treatment because its underlying mechanisms remain poorly understood. This study investigated the long-term efficacy of a personalized 10 Hz amplitude-modulated (AM) sound enrichment protocol in comparison with an unmodulated (UM) protocol. Seventy-one participants with chronic tonal tinnitus were assigned to either a modulated group (MG, n = 27), which underwent a 10 Hz AM sound complex, or an unmodulated group (UMG, n = 44), which underwent an unmodulated sound complex. Stimuli were individually customized by spectrally shaping a noise band to compensate for each participant's audiometric hearing loss and by increasing energy around their specific tinnitus pitch. Outcomes included the Tinnitus Handicap Inventory (THI), tinnitus loudness level (TLL), and minimum masking level (MML), assessed at baseline and at 1, 3, and 6 months. Both groups showed significant improvements in THI, TLL, and MML over 6 months (p < .001). However, the MG demonstrated a significantly greater reduction in MML compared with the UMG (F(1,69) = 4.001, p = .049). A higher proportion of participants in the MG reported complete tinnitus suppression (18.51%) compared with the UMG (4.54%). Customized sound enrichment is an effective long-term treatment for tinnitus associated with hearing loss. Incorporating 10 Hz amplitude modulation provides an additional benefit by reducing MML, suggesting that patients become less sensitive to tinnitus perception. These findings highlight the importance of an individualized approach and support the use of modulated stimuli such as 10 Hz AM sound in long-term treatment protocols.