OPTIMAL ONE-DIMENSIONAL AND 2-DIMENSIONAL FILTERING OF TRANSIENT-EVOKED OTOACOUSTIC EMISSIONS

In the clinical use of evoked otoacoustic emissions the identification of the cochlear response and the reduction of the duration of the rec ording session are of great concern, especially if the recorded respon ses are to be used in hearing screening tasks. The aim of this paper i s two-fold: to examine the potential and limits of optimal band-pass f iltering to reduce the noise and increase identification of the cochle ar response, and to introduce a technique of two-dimensional processin g for reducing the acquisition time of TEOAEs. Band-pass filtering mus t guard against the loss of significant frequency components of the re sponse; that is, the signals have to be filtered only when the filter bandwidth meets given conditions. As to test duration, preliminary res ults clearly indicate that two-dimensional filtering can substantially reduce the acquisition time, with only negligible losses in the basic response features, when a set of responses recorded at different stim ulus levels is filtered.