The sound intensity-related behaviour of the brain stem response P6 in different forms of hearing disorders

Abstract

For clinical purpose it seems appropriate to emphasize especially P6 among the auditory evoked responses (AER). The latency of this positive wave after approximately 6 ms shows a close correlation of the sound intensity: approximately 9.5 ms at the hearing threshold, approximately 5.8 ms at 100 dB CHL (click hearing level). The different forms of hearing disorders always reveal typical latency patterns. Thus, middle ear hearing loss can be distinguished form inner ear hearing loss, and among sensory lesions those of moderate hearing loss exhibit another pattern than those of severe hearing loss. In the same way among neural disorders two types can be separated from each other, probably caused by different ways of genesis. Thus, ERA (electric response audiometry) becomes an objective pendant to the suprathreshold tests and an integrated part of clinical audiometry.