Audiometer: Evoked Response
Raghbir Singh Khandpur · Compendium of Biomedical Instrumentation · 2019
This chapter discusses the purpose, principle, specifications, and applications of evoked response audiometer. An evoked response audiometer is a diagnostic device that is used in the place of conventional audiometers especially for the purpose of diagnosing possible defects in the vestibulocochlear nerve and brainstem auditory pathways, infant hearing screening and evaluation and determination of hearing loss type and degree. The stimulus generator is a wide range pure tone audiometer whose frequency output can be selected in the range from 250 to 8000 Hz. Modern evoked response audiometers are built around microcomputers. In the two-channel recorder, one channel is used to display the averaged response after it has been processed by the computer and the other displays unprocessed EEG. The amplitude of the evoked response may be normalized to that of the on-going EEG monitoring signal using a gain control.