Amplitude modulated S-Tones can be superior to noise for tinnitus reduction

Recent evidence has suggested that amplitude modulated tones might have some advantages over broadband noise. Method: Fifty-six subjects listened to S-Tones at a carrier frequency matched at the tinnitus pitch (amplitude modulation rate of 40 Hz) and to broadband noise. Subjects rated their tinnitus loudness before, during, and after a 120-s duration masker. Results: The results suggested that S-Tones were generally more effective at reducing tinnitus loudness than noise. In about one third (21/56) of the subjects, there was no significant effect from any masker. In other subjects, 54.3% (19/35) showed a greater reduction for the S-Tones, 20% (7/35) showed a greater reduction with the noise, and 25.7% (9/35) showed similar performance between the 2 stimuli. The S-Tones showed a statistically significant benefit (p <.01) versus noise at reducing the patient's tinnitus perception. Using low-level stimuli that were rated much softer than the subjects' baseline tinnitus, the S-Tones reduced the tinnitus loudness by 1.9 times the amount that noise did (about 28% on average, whereas the noise reduced the tinnitus by about 15%). Conclusion: S-Tones at the tinnitus pitch-match frequency are more likely to be effective than broadband noise at reducing tinnitus loudness.