To independently evaluate phase-shift treatment for predominant tone tinnitus.
Prospective, single-blinded crossover study.
61 subjects with predominant tone tinnitus participated in 2 weeks of control and 2 weeks of phase-shift treatment. Frequency and intensity matching, pre- and post-treatment tinnitus handicap inventory (THI) scores, and patient diaries were outcome measures.
Initial volume comparisons show a strong relationship between treatment and decrease in tinnitus intensity, with 57% of patients achieving successful treatment. Thirty-seven percent decreased by one THI grade, 5% by two. Utilizing patient diaries, 42% of patients reported periods of complete residual inhibition (CRI) ranging from 1 hour to 7 days (average 2 days). No periods of CRI were reported in control weeks.
Phase-shift treatment significantly benefited the majority of our patients. These outcomes suggest that this device may be a valuable tool. Further long-term studies with home therapy are warranted.