Diagnosis of abnormal hearing adaptation by brainstem potentials.
Adaptation of the human brainstem potentials was investigated using three types of stimulation: paired clicks, varied click rates, and a gap in a continuous tone. Brainstem responses to the second of a pair of clicks is hardly influenced by pathological adaptation. In patients with a normal subjective threshold decay (Carhart test) peak V latencies of the brainstem potential for high click rates and for the tone gap were within the normal range. For a threshold decay of more than 20 dB, latencies were significantly prolonged. In cases of an unlimited Békésy decay the brainstem response was missing for the tone gap stimulus. Fast rate and tone gap stimulation are suitable for a sensitive illustration of the threshold tone decay.
D000222:Adaptation, Physiological; D001299:Audiometry / Q000379:methods; D001309:Auditory Threshold; D001933:Brain Stem / Q000502:physiology; D005072:Evoked Potentials, Auditory; D006311:Hearing Disorders / Q000175:diagnosis* / Q000503:physiopathology; D006801:Humans; D011930:Reaction Time