People with noise related hearing loss, frequently experience ringing or other noise, is very difficult to treat. German researchers have developed a form of customized music therapy, to treat people with tinnitus.

The treatment was developed at the Muenster University hospital utilizes new information regarding tinnitus’ potential cause, a reformation of the portion of the brain, the auditory (hearing) cortex that is responsible for hearing. Also additional research suggests this abnormality may be altered by behavioral training.
Patients selected their favorite music, 12 hours a week, which was altered to filter out the frequency of the ringing sounds. Their tinnitus decreased significantly, compared to others who listened to music with frequencies that did not correspond to their specific ringing level.
Music therapy is currently used to treat many conditions. This is the first report of its successful use in treating tinnitus.

Source:
http://www.pnas.org/content/early/2009/12/15/0911268107.abstract