Effects of oxygen inhalation on noise-induced threshold shifts in humans and chinchillas.

Experiments with both humans and chinchillas indicate that the temporary threshold shift after ten-minute stimulation with 100 dB sound pressure level 1 kHz tone diminished more quickly if the subject breathed pure oxygen and it diminished even more quickly when 95% oxygen-5% carbon dioxide was inhaled rather than ambient air. This effect was observed for both poststimulatory and per-stimulatory gas inhalation.