Hearing loss of a central type secondary to carbon monoxide poisoning.

The effect of carbon monoxide poisoning on the threshold sensitivity of the responses from the auditory cortex, inferior colliculus, and cochlea to acoustic stimuli in guinea pigs was studied. The toxicity of carbon monoxide is believed to be secondary to tissue hypoxia and is partially reversible. Loss of auditory threshold sensitivity in carbon monoxide poisoning is most prominent at the auditory cortex. The loss of sensitivity at the inferior colliculus is the next most severe. There is no loss of sensitivity at the cochlea. The relative vulnerability of the central auditory pathway to carbon monoxide poisoning as compared with the end organ is demonstrated.