Early auditory-evoked responses: filter effects.

Abstract

The early auditory-evoked responses have been recorded in 4 human subjects and 3 cats using a filter band-pass of 2-5 000 Hz. The responses have been subsequently analogue-filtered at different low-pass and high-pass settings. Reduction of low-pass cut-off produces latency increases of similar magnitudes for all waves. Raising the high-pass cut-off results in dramatic changes in the responses, the peaks of the waves being apparently deflected onto the succeeding wave flanks, thus resulting in false latency reductions. The individual waves are affected at different filter settings dependent on their frequency content.