Several workers have investigated the susceptibility of cochlear potentials to oxygen deprivation. The results showed that cochlear microphonics, action potentials, and DC resting potential are oxygen-dependent. Bekesy 1 demonstrated that both cochlear microphonics and DC resting potential, as recorded from scala media, followed the same time-course decay during anoxia. Wever et al. 2 reported that in the cat the amplitude of cochlear microphonics diminished when the concentration of oxygen in the respirating gas mixture was below 4%. Lawrence and Wever 3 reported a detectable lesion in the organ of Corti of cats exposed to severe oxygen deprivation. However, Falbe-Hansen et al. 4 did not find such changes in guinea pigs and cats exposed to either acute or prolonged oxygen lack. Bornschein and Gernandt 5 showed that by repeating the exposure to anoxia, the neural components can be removed selectively from cochlear microphonics. But according to other investigations 6 this method