Effects of Carbon Dioxide and Oxygen Levels on Auditory Sensitivity and Frequency Tuning as Measured by the Stimulus Frequency Otoacoustic Emission Test
Technical rept. 2002-2004
NAVAL SUBMARINE MEDICAL RESEARCH LAB GROTON CT
Pagination or Media Count:
Exposure to hazardous noise results in increased reactive oxygen species ROS activity within the cochlea that causes damage to the outer hair cells, the result is noise-induced, sensorineural hearing loss. Evoked otoacoustic emissions EOAEs are an electrophysiological measure of inner ear activity that reflects cochlear outer hair cell functioning during the processing of auditory stimuli. Stimulus frequency OAE SFOAE have the potential to assess both the sensitivity and the tuning capabilities of the cochlea. This study assessed the sub-clinical effects of increased oxygen andor carbon dioxide levels on inner ear processing of sound as reflected by SFOAE absolute amplitude and changes in the phase of the SFOAE response as test frequencies are increased. The results of this study indicate cochlear processing is affected by breathing higher than normal levels of oxygen and carbon dioxide, but generalization of the results is limited by the small number of subjects tested. Further research is needed with a larger sample size to determine if significant changes in SFOAE amplitudes have a harmful or protective effect on cochlear functioning.
- Anatomy and Physiology