Whereas, there may be a more obvious steeply sloping loss at high frequencies for a high frequency dead region. Although it is likely that the slope represents the less pronounced downward spread of excitation, rather than accurate thresholds for those frequencies with non-functioning hair cells. Mid-frequency dead regions, with a small range, appear to have less effect on the patients ability to hear in everyday life, and may produce a notch in the PTA thresholds. Although it is clear that PTA is not the best test to identify a dead region. Psychoacoustic tuning curves (PTC) and threshold equalizing noise (TEN) tests
Although some debate continues regarding the reliability of such tests, it has been suggestedthat psychoacoustic tuning curves (PTCs) and threshold-equalising noise (TEN) results may be useful in detecting dead regions, rather than PTA. PTCs are similar to neural tuning curves. They illustrate the level of a masker (dB SPL) tone at threshold, as a function of deviation from center frequency (Hz). They are measured by presenting a fixed low intensity pure tone while also presenting a narrow-band masker, with a varying center frequency. The masker level is varied, so that the level of masker needed to just mask the test signal is found for the masker at each center frequency. The tip of the PTC is where the masker level needed to just mask the test signal is the lowest.
A typical source of acoustic trauma is a too-loud music concert. Workplace noise: The OSHA standards 1910.95 General Industry Occupational Noise Exposure and 1926.52 Construction Industry Occupational Noise Exposure identify the level of 90 dB(A) for 8 hour exposure as the level necessary to protect workers from hearing loss. Disease or disorder
Inflammatory
Suppurative labyrinthitis or otitis interna (inflammation of the inner ear)
Diabetes mellitus  A recent study found that hearing loss is twice as common in people with diabetes as it is in those who dont have the disease. Also, of the 86 million adults in the U.S. who have prediabetes, the rate of hearing loss is 30 percent higher than in those with normal blood glucose. It has not been established how diabetes is related to hearing loss. It is possible that the high blood glucose levels associated with diabetes cause damage to the small blood vessels in the inner ear, similar to the way in which diabetes can damage the eyes and the kidneys. Similar studies have shown a possible link between that hearing loss and neuropathy (nerve damage). Tumor
Cerebellopontine angle tumour (junction of the pons and cerebellum) – The cerebellopontine angle is the exit site of both the facial nerve(CN7) and the vestibulocochlear nerve(CN8). Patients with these tumors often have signs and symptoms corresponding to compression of both nerves.