Tinnitus most common causes is noise-induced hearing loss. Other causes include ear infections, disease of the heart or blood vessels, Ménière's disease, brain tumors, emotional stress, exposure to certain medications, a previous head injury, and earwax. It is more common in those with depression. The diagnosis of tinnitus is usually based on the person's description. A number of questionnaires exist that may help to assess how much tinnitus is interfering with a person's life. The diagnosis is commonly supported by an audiogram and a neurological examination. If certain problems are found, medical imaging, such as with MRI, may be performed. Other
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