Hypoxia and auditory thresholds

This paper reports the effects of hypoxia on hearing. Pure tone hearing and speech discrimination were tested at ground level and during hypoxic states at simulated altitudes of 4,600 m (15,000 ft) and 6,100 m (20,000 ft) in a high-altitude chamber. Pure tone hearing was not significantly altered during hypoxia produced by this method. Speech discrimination showed alterations, possibly due to central nervous system hypoxia. It was concluded that hypoxia does not cause significant deterioration of hearing for pure tones.