The Challenges of Treating Higher Frequency Tinnitus
The authors of a Notched Music Therapy study discuss why they believe that Notched Music does not work in people with a tinnitus frequency over 8,000 hZ (A.K.A. 8 khZ):
An additional crucial finding was that the TMNMT efficacy depended on the tinnitus frequency. Even though we had relatively amplified high frequency music energy during the filtering process (Figure 4), and despite having utilized a headphone that reliably transduced very high frequencies, the TMNMT was on average only effective for patients with tinnitus frequencies ≤8 kHz, but not for patients with frequencies above this value. From a theoretical viewpoint, this finding is plausible for several reasons:
(i) the sensitivity of the human cochlea is comparably low for very high frequencies . Thus, much larger sound pressure levels must be used to make very high frequencies audible.
(ii) Age-related hearing loss progresses from the highest to the lower frequencies . Hence, this factor adds to the cochlea’s general relative insensitivity for very high frequencies.
(iii) Music usually contains relatively little very high frequency energy.
(iv) Eventually, during listening the patients might involuntarily have paid most attention to the rather low frequencies (for instance to the voices of the singers), which are more relevant for music perception and enjoyment than the rather high frequencies. Taken together, these arguments demonstrate that it would be challenging to effectively suppress the activity of target neurons coding very high tinnitus frequencies, and it remains to be investigated whether the TMNMT could principally work for tinnitus patients with tinnitus frequencies >8 kHz. On the one hand, it appears reasonable to assume that for such cases the treatment stimulus should contain a sufficient amount of high frequency energy. On the other hand, we presume that it would be important that the treatment stimulus and strategy remained interesting or motivating enough to activate attention- and reward-related networks of the brain thought to promote plastic change. One possibility would be to further enrich the music spectrum in the high frequency range, for instance by adding high-pass noise.
Please note – Notched White Noise has shown efficacy in individuals with a tinnitus frequency up to 13,000 hZ (A.K.A. 13 khZ), hence our recommended treatment protocol: