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 range and bandwidth in cases of narrow band noise tinnitus, loudness in dB above hearing threshold at the indicated frequency, mixing-point, and minimum masking level. In most cases, tinnitus pitch or frequency range is between 5 kHz and 10 kHz, and loudness between 5 and 15 dB above the hearing threshold. Another relevant parameter of tinnitus is residual inhibition, the temporary suppression or disappearance of tinnitus following a period of masking. The degree of residual inhibition may indicate how effective tinnitus maskers would be as a treatment modality. An assessment of hyperacusis, a frequent accompaniment of tinnitus, may also be