Formant Tracking by Majority Weighting of Period Measurements

Abstract

A formant-tracking method based on the measure of majority period is discussed. This tracker employs as input data the instantaneous period measures of formants that have been selected by appropriate formant-range filters. These periods are subjected to an electronic circuit that, by a unique feedback arrangement, suppresses periods that deviate beyond a fixed threshold distance from the mean period. The resulting circuit output very nearly tracks the majority period of the set of periods that originally comprised the input data. The method also incorporates a means of weighting the majority period formant measure toward the median of the formant range. By this means, the tendency to be captured by adjacent formants is significantly reduced. The paper describes the method of implementation and the application of the method to formant tracking in the second-formant range. [Research supported in part by U. S. Army Electronics Research and Development Laboratory.]