Listening to tailor-made notched music reduces tinnitus loudness and tinnitus-related auditory cortex activity

Abstract

Maladaptive auditory cortex reorganization may contribute to the generation and maintenance of tinnitus. Because cortical organization can be modified by behavioral training, we attempted to reduce tinnitus loudness by exposing chronic tinnitus patients to self-chosen, enjoyable music, which was modified ("notched") to contain no energy in the frequency range surrounding the individual tinnitus frequency. After 12 months of regular listening, the target patient group (n = 8) showed significantly reduced subjective tinnitus loudness and concomitantly exhibited reduced evoked activity in auditory cortex areas corresponding to the tinnitus frequency compared to patients who had received an analogous placebo notched music treatment (n = 8). These findings indicate that tinnitus loudness can be significantly diminished by an enjoyable, low-cost, custom-tailored notched music treatment, potentially via reversing maladaptive auditory cortex reorganization.

Fig. 1.

Target treatment. A frequency band of one octave width centered at the individual tinnitus frequency was removed from the music energy spectrum via digital notch filter. Exemplary music (MP3 format) is available as Movie S1.

Fig. 2.

Placebo treatment. A moving notch filter (dotted arrow) of one octave width was applied to the music energy spectrum. The energy in the frequency band ranging from 0 to 707 Hz and the energy in the 1-octave frequency band surrounding the individual tinnitus frequency remained strictly unchanged (dark gray areas). The energy in the remaining frequency ranges was subject to filtering (light gray areas). Exemplary music (MP3 format) is available as Movie S2.

Fig. 3.

Normalized tinnitus loudness change after 6 and 12 months of treatment (or monitoring) relative to baseline (0) for the three patient groups (target, placebo, and monitoring). Positive change values reflect impairment, negative change values reflect improvement. The bars indicate group averages, each x indicates an individual data point. The error bars denote confidence intervals. The data were normalized as following: {[(tinnitus loudness_AVG months 1–6 or months 7–12/tinnitus loudness_baseline) − 1] × 100}. As indicated by the confidence interval bars, only the changes in the target group were statistically significant.

Fig. 4.

Normalized tinnitus-related auditory cortex evoked activity change after 6 and 12 months of treatment (or monitoring) relative to baseline (0) for the three patient groups (target, placebo, and monitoring). Positive change values reflect increment, negative change values reflect decrement. The bars indicate group averages, each × indicates an individual data point. The error bars denote confidence intervals. ASSR change values are reflected by white bars, N1m change values are reflected by gray bars. The data were normalized as following: {[(ASSR or N1m_tinnitus frequency after 6 or 12 months/ASSR or N1m_control frequency after 6 or 12 months)/(ASSR or N1m_tinnitus frequency baseline/ASSR or N1m_control frequency baseline) − 1] × 100}. As indicated by the confidence interval bars, only the changes in the target group were statistically significant.