This project aims to evaluate the clinical efficacy of Yiyuancong, an independently developed traditional Chinese medicine (TCM) formula based on the homology of medicine and food, in participants with sudden sensorineural hearing loss (SSNHL) and to elucidate its potential underlying mechanisms. This study is designed as a multicenter, randomized controlled trial (RCT), utilizing dynamic randomization for participant allocation. Due to the requirement for the experimental group to continuously administer the TCM preparation for 1-2 months, this study is conducted as an open-label (non-blinded) trial. All participants will undergo audiological evaluations at baseline, day 7 of treatment, and upon completion of the first and second treatment courses.
Based on previous research regarding integrated traditional Chinese and Western medicine for SSNHL, the estimated effect size (ES) for the improvement of pure-tone thresholds compared with Western medicine alone ranges from 0.5 to 0.8. Assuming an effect size of 0.5 for the difference in pure-tone audiometry (PTA) improvement between the experimental and control groups, with a significance level (α) of 0.05 (one-tailed) and a statistical power (1-β) of 0.8, the required sample size calculated via G\*Power software is 51 per group. Accounting for a 20% dropout rate, the investigators plan to enroll 64 participants per group (total N = 128).