Tinnitus to the inner ear can cause tinnitus, other apparent causes (e.g., temporomandibular joint dysfunction) are difficult to explain. It may be caused by increased neural activity in the auditory brainstem, where the brain processes sounds, causing some auditory nerve cells to become over-excited. The basis of this theory is that many with tinnitus also have hearing loss. Three reviews of 2016 emphasized the large range and possible combinations of pathologies involved in tinnitus, which in turn result in a great variety of symptoms demanding specifically adapted therapies. Even when tinnitus is the primary complaint, audiological evaluation is usually preceded by
Tinnitus retraining therapy with tinnitus have a comorbid psychological injury or illness (e.g., post-traumatic stress disorder, depression, anxiety, obsessive compulsive disorder, stress, dysfunction of the temporomandibular joint, etc.) that can exacerbate the tinnitus. It has been proposed that tinnitus is caused by mechanisms that generate abnormal neural activity, specifically one mechanism called discordant damage (dysfunction) of outer and inner hair cells of the cochlea. The psychological basis for TRT stems from the fact that the brain exhibits a high level of plasticity. In turn, this allows it to adjust to any sensory signals as long as they do not lead to negative effects.