Transcutaneous Auricular Vagus Nerve Stimulation Combined With Tailor-Made Notched Music Training Therapy for Chronic Subjective Tinnitus: A Multicenter, Randomized, Controlled, Open-label Trial

This study is a prospective, multicenter, randomized, controlled, open-label clinical trial designed to evaluate the superiority of transauricular vagus nerve microcurrent stimulation (taVNS) combined with Tailor-Made Notched Music Training (TMNMT) compared with Tinnitus Retraining Therapy (TRT) in patients with chronic subjective tinnitus. A total of 386 participants aged 18-70 years with a tinnitus duration of at least 6 months and a Tinnitus Handicap Inventory (THI) score ≥38 will be enrolled, excluding individuals with severe hearing loss, organic cranial diseases, or other contraindications. Eligible participants will be randomly assigned in a 1:1 ratio to either the experimental group or the control group. The control group will receive standardized TRT, including habituation sound therapy and structured educational counseling, while the experimental group will receive TMNMT combined with taVNS (0.1 Hz pulse-train stimulation, sub-pain threshold intensity of 0.5-10 mA). Although the trial is open-label, outcome assessors and statisticians will remain blinded to group allocation. Baseline and follow-up assessments include THI, visual analog scale (VAS), Beck Anxiety Inventory (BAI), Beck Depression Inventory (BDI), Pittsburgh Sleep Quality Index (PSQI), audiological evaluations, and multimodal neuroimaging using EEG and fMRI. The primary outcome is the tinnitus improvement response rate at 3 months after treatment initiation, defined as a reduction of more than 7 points in the THI score from baseline. Secondary outcomes include treatment response rates at 6 and 12 months, changes in tinnitus severity and tinnitus-related comorbid symptoms, and neuroplasticity-related changes in central neural mechanisms.