Hearing loss related to zinc deficiency in rats.

Based on the observation that the zinc concentration in the cochlea of guinea pigs is very high, Shambaugh in North America has suggested that zinc plays an important role in hearing. Zinc deficiency is not infrequently present in growing children and elderly people, and thus might result in a hearing loss, which should be treated with zinc supplementation. The present experiment examined the effects of a zinc-deficient diet on hearing in 7-week-old rats. The auditory brainstem response threshold was measured in four rats before, during and after a zinc-deficient diet. Concentrations of zinc in the brain and in several other organs were measured, and the cochleas were examined microscopically. No hearing loss or morphological change in the cochlea of these animals was detected, although a clear zinc-deficient status was reached.