Abstract: Different evoked potentials from the auditory system in response to acoustic stimulation were recorded in guinea pigs, monkeys and human subjects.The evoked responses were processed by a computer with the application of the time-varying filtering(TVF) technique which in essence is a time-varying output weighting of the signal after passing through a set of band-Pass filters in correspondence to the time-vary-lug signal/noise ratio of each response.Comparison revealed that the brain stem responses, the cochlear action potentials, the primary responses of the auditory cortex,the periaural responses as well as the slow cortical responses in both animals and hvmans, the response waveform is much clearer in results of the TVF p prdoessing than in those of the ordinary averaging with the TVF processing, the background noise may be markedly suppressed in some cases even to a flat line. The TVF technique hence may serve as a useful means in evoked response recording and its application seems especially efficient in response threshold determination.