Evaluation of some nonrecursive digital filters for signals of auditory evoked responses.

Auditory brain stem evoked responses are routinely used in audiology and otoneurology. Because recordings include more or less noise, the signals of evoked responses need digital filtering to suppress the noise. Nonrecursive digital filters are often the best since they can be organized to have no phase shift, which is essential in order not to distort sensitive parameters, as latency, in evoked responses. We have studied effects of some nonrecursive digital filters on the latency parameters of evoked responses. It turned out that digital filtering can have considerable influence on latencies, and thus the choice of appropriate filters is crucial.