Subjective tinnitus, the ringing or other noise that often accompanies noise-related hearing loss, is a tough problem to treat. But researchers in Germany have come up with a novel approach, a kind of music therapy in which the music is custom-tailored to the person with tinnitus.
The technique, by Hidehiko Okamoto, Henning Stracke and Christo Pantev of Westfalian Wilhelms-University and Wolfgang Stoll of Muenster University Hospital, makes use of recent findings about a possible cause of tinnitus: reorganization of the auditory cortex, the part of the brain responsible for perceiving sound, in response to noise exposure. Other research has shown that behavioral training may reverse faulty cortical reorganization.
The researchers allowed patients to choose their favorite music, which was then “notched” — a one-octave frequency band, centered on the frequency of the ringing experienced by the subject, was filtered out. The subjects listened to the music on average about 12 hours a week.
After a year, the researchers report in The Proceedings of the National Academy of Sciences, those who listened to this custom-notched music reported a significant improvement in their tinnitus — the ringing was not as loud — compared with others who listened to music that was notched at frequencies not corresponding to their ringing frequency.
The researchers suggest that two things might be happening in the auditory cortex to bring about the improvement. The neurons in the cortex related to the ringing frequency are presumably not being stimulated, because those frequencies are absent from the music. At the same time, nearby neurons may have been actively suppressing the tinnitus-related neurons, through a process known as lateral inhibition.