[Cross correlation functions of acoustic evoked brain stem potentials]

A method for the analysis of brainstem acoustic evoked potentials (BAEP) is presented. The calculation of the normalized cross correlation function between BAEP recordings of the right and left side yields a quantitative and objective valuation of the symmetry of the electrical brainstem activity. Contrary to the usual interpretation of latencies and amplitudes the BAEP waveform is also considered. To demonstrate the regular properties of the normalized cross correlation function 20 healthy subjects were tested. Different stimulus and recording conditions, the influence of the BAEP signal length on which the calculation of the cross correlation function is based as well as filtering of the BAEP with varying cutoff frequencies are studied.