Mixed hearing loss

Audiologists are concerned with three kinds of hearing loss conductive hearing loss, in which sound waves are not properly transmitted to the inner ear sensorineural hearing loss, in which the cochlea or the auditory nerve is damaged and mixed hearing loss, which is a combination of these. 

Mixed hearing loss is a blend of sensorineural and conductive hearing loss and generally results in increases in all ABR frequency thresholds. 

All the BTEXs cause neurological effects. Neurological effects are the basis for MRLs for both acute and chronic exposures to toluene and mixed xylenes, and for intermediate exposures to benzene neurological effects are not as sensitive for ethylbenzene. The neurological effects consist primarily of central nervous system depression. Toluene s neurotoxicity also includes ototoxicity. Evidence of hearing loss has been seen in both occupationally exposed humans and in animals. There is limited evidence that chronic inhalation exposure to benzene may affect the peripheral nervous system this evidence is from a single study of occupationally exposed humans who also had aplastic anemia. 

When hearing loss is present following NCE administration, one of three categories is typically observed conductive, sensorineural, or mixed ... 

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