Tinnitus or "vibratory" tinnitus. Subjective tinnitus is the most frequent type of tinnitus. It can have many possible causes, but most commonly it results from hearing loss. When the tinnitus is caused by disorders of the inner ear or auditory nerve it is called otic (from the Greek word for ear). These otological or neurological conditions include those triggered by infections or drugs. A frequent cause is noise exposure that damages hair cells in the inner ear. When there does not seem to be a connection with a disorder of the inner ear or auditory nerve, the tinnitus is called nonotic
Tinnitus retraining therapy large proportion of dropouts; reported 'success' ratios may not take these subjects into account. There are few available studies, but most show that tinnitus naturally declines over time (years) in a large proportion of subjects surveyed, without any treatment. The annoyance of tinnitus also tends to decline over time. In at least some, tinnitus spontaneously disappears. A Cochrane review found only one sufficiently rigorous study of TRT and noted that while the study suggested benefit in the treatment of tinnitus, the study quality was not good enough to draw firm conclusions. A separate Cochrane review of sound therapy (though they