Tinnitus: the dark side of the auditory cortex plasticity.

Music has increasingly been used as a tool for investigation of human cognition and its underlying brain mechanisms. However, music can be used also for neurorehabilitation. Chronic tinnitus is a symptom with high prevalence, especially in industrialized countries. There is evidence that the tinnitus perception is related to unfavorable cortical plastic changes. Maladaptive auditory cortex reorganization may contribute to the generation and maintenance of tinnitus. Because cortical organization can be modified by behavioral training, potentially via reversing maladaptive auditory cortex reorganization, we attempted to reduce tinnitus loudness by exposing chronic tinnitus patients to self-chosen, enjoyable music that was modified ("notched") to contain no energy in the frequency range surrounding the individual tinnitus frequency and thus attracting lateral inhibition to the brain area generating tinnitus. On this basis, we have developed and evaluated a customized music training strategy that appears capable of both reducing cortical tinnitus-related neuronal activity and alleviating subjective tinnitus perception.