Brain Stem Auditory Evoked Response

Abstract

Brain stem auditory evoked responses (BAER) elicited by bone-conducted click stimuli were studied in 37 subjects. This technique was plagued with problems such as: low amplitude, poor wave configuration, and calibration difficulties. The authors found the technique of limited value in differentiating conductive from neurosensory hearing disorders in all but severely affected subjects. It can, however, evaluate cochlear function in the presence of a known severe conductive hearing loss, ie, external ear atresia. If an abnormal bone-conducted BAER is obtained the etiology of this abnormality (cochlear vs. retrocochlear) cannot be ascertained because a wave I is rarely elicited in individuals with neurosensory hearing disorders. In subjects with a severe conductive hearing loss, air-conduction elicited markedly prolonged wave V latencies. Such a marked prolongation was not observed in individuals with peripheral neurosensory loss and when present signified that a subject had a major conductive component to his hearing disorder. The authors also believe that all control subjects should be established as normal with an audiogram and not by an otologic history or auditory (subjective) click thresholds.