Now make your toes as tight as you can, really scrunch them up. Hold them like this for a moment – and relax. Now do the same with your ankles, then your calf muscles, your thighs… work all the way up your body to your head, making sure you tense, hold for a moment, and then release the tension. Once you’ve done this with your whole body, focus again on your breathing – notice the rhythm, it should be even and calm.
Individuals were recruited from within and around Hamilton, Ontario via online announcements and audiology clinics. Applicants were initially interviewed via telephone to screen for all inclusion and exclusion criteria for the study in order to determine whether they qualified for on-site screening. The on-site screening, and characterization of participants’ hearing thresholds and tinnitus profiles were conducted in a lab at McMaster University using a computer-based tinnitus assessment tool. Participants were randomly allocated to the treatment or placebo-control group. The assignment of the treatment or placebo music package was completed by a distributor site independent of the research study site. Participants and research personnel were blinded to which music package the participants received.
Sound-masking devices provide a pleasant or benign external noise that partially drowns out the internal sound of tinnitus. The traditional sound-masking device is a tabletop sound machine, but there are also small electronic devices that fit in the ear. These devices can play white noise, pink noise, nature noises, music, or other ambient sounds. Most people prefer a level of external sound that is just slightly louder than their tinnitus, but others prefer a masking sound that completely drowns out the ringing.
Until recently, most tinnitus patients had little reason to believe doctors would ever be able to completely cure or reverse the affliction. Drug therapies had consistently failed, and so had more invasive procedures — including some surgeries to remove the auditory nerve that transmits sound from the ear to the brain, according to past research. (1,2)
TRT depends upon the natural ability of the brain to "habituate" a signal, to filter it out on a subconscious level so that it does not reach conscious perception. Habituation requires no conscious effort. People frequently habituate many auditory sounds -- air conditioners, computer fans, refrigerators, and gentle rain, among them. What they have in common is that they have no importance, so they are not perceived as ''loud.'' Thus, the brain can screen them out.
The researchers next tested whether tinnitus could be reversed in noise-exposed rats. The animals received VNS paired with various tones other than the tinnitus frequency 300 times a day for about 3 weeks. Rats that received the treatment showed behavioral changes indicating that the ringing had stopped. Neural responses in the brain's auditory cortex returned to their normal levels as well, indicating that the tinnitus had disappeared.
This tinnitus treatment we developed makes use of software that customizes a music-based therapy for each individual tinnitus sufferer. The software achieves this by incorporating a computational model of the “tinnitus brain.” This model captures changes in the auditory brain which may be causing the tinnitus.5,7 We do this by taking into account the individual’s audiogram and a pitch match of their tinnitus, which generates a tinnitus profile unique to him or her. The software then uses the model to predict how each music track can be altered spectrally to reduce tinnitus for that specific tinnitus profile. Delivering the treatment using headphones that could produce high frequencies (above 10–12 kHz) was an integral part of treatment effectiveness. With such headphones, the treatment could work by taking advantage of the same kind of brain plasticity that may contribute to the person's tinnitus in the first place without being limited by a lack of high-frequency sounds.8 By incorporating the latest tinnitus research into our software, we developed a treatment approach that provides greater promise in treating tinnitus than existing treatments with a one-size-fits-all approach.
Exposure to loud noise. Loud noises, such as those from heavy equipment, chain saws and firearms, are common sources of noise-related hearing loss. Portable music devices, such as MP3 players or iPods, also can cause noise-related hearing loss if played loudly for long periods. Tinnitus caused by short-term exposure, such as attending a loud concert, usually goes away; both short- and long-term exposure to loud sound can cause permanent damage.