Rapid acquisition and tracking of evoked potentials by two dimensional spectral filtering

A two dimensional spectral filtering method is used to enhance auditory brainstem response recordings obtained serially from normal subjects. Spectral filtering using a Gaussian filter gain profile is shown to introduce less distortion than that produced by rectangular filtering profiles. With the proposed filtering method, the authors were able to reduce the number of sweeps averaged to produce a discernable recording from 1024 to 32 or 16. This reduction in recording time allows fast tracking of ABR transitions which would be impossible with current techniques. Experiments performed on simulated data and data obtained from normal subjects at changing intensities show that dynamic tracking of ABR waves with fast updates (1-2 seconds) are realizable