Exposure to low level noise prior to a high level exposure reduces noise-induced hearing
loss in mammals. This phenomenon is known as sound conditioning ortoughening'.
Reactive oxygen intermediates have been implicated in noise-induced cochlear damage. To
evaluate if in situ antioxidant processes may play a role in the toughening phenomenon
initiated by low level noise exposure we analyzed glutathione reductase, γ-glutamyl cysteine
synthetase, and catalase in stria vascularis and organ of Corti fractions from cochleae of …