The positive rate of recruitment phenomenon in tinnitus patients and hyperacusis patients

Abstract

Hyperacusis and tinnitus often occur in the same patient. It is unclear whether hyperacusis and tinnitus are separate phenomena or possess the same etiology. This study analyzed 80 tinnitus patients and 24 hyperacusis patients who had no hearing disturbance. These patients underwent an SISI (short increment sensitivity index) test, MCL/UCL (most comfortable loudness level/uncomfortable loudness level) test, Bekesy audiometry and Metz test, and were examined the positive rate of the recruitment phenomenon. The positive rates of recruitment phenomenon were 25-63% and 33-38% in tinnitus and hyperacusis patients, respectively, showing no differences. The positive rate in the symptomatic ear was slightly higher in the hyperacusis ears (15.5%) than in the tinnitus ears (10.3%).