Effects of in-situ calibration of click stimuli on the auditory brainstem response

We studied the effects on the auditory brainstem response (ABR) of applying a computerized calibration procedure for click stimuli that corrects for individual transducer characteristics and ear canal acoustics. The "calibrated" signal at the eardrum possesses a nearly flat spectrum from 500 to 10,000 Hz. ABRs were recorded from normal-hearing subjects using both calibrated and uncalibrated clicks. The preponderance of energy for the latter stimulus was between 1000 and 4000 Hz. When compared to the responses evoked by the uncalibrated signal, ABRs to calibrated clicks displayed shorter component latencies, increased component amplitudes, and a more sensitive wave V relative to behavioral threshold.