The questionable relation between cochlear pigmentation and noise-induced hearing loss.

Some evidence has suggested that susceptibility to noise-induced hearing loss may be inversely proportional to the amount of melanin in the cochlea. However, published data have not been consistent in demonstrating this relation, and some results may be contaminated by lack of genetic control in experimental animals. In this investigation, noise-induced hearing loss was evaluated in pigmented and albino C57BL/6J mice that differed only in their ability to produce melanin. Surface-recorded electric responses to sound were used to assess auditory sensitivity. Results indicated no difference between the two groups either in pre-exposure thresholds or in magnitude of noise-induced threshold shift.