Minimizing the effect of period determination on the computation of amplitude perturbation in voice

Abstract

Current methods of computing amplitude perturbation present in human voices depend upon being able to accurately determine fundamental period. In this paper, two methods of estimating the amplitude perturbation present in human voices, which do not depend on accurate determination of the boundaries between fundamental periods, are described. In both of these methods, amplitude perturbation is computed as the variance of an ensemble of periods calculated after these periods have been aligned in time. In one method, time alignment is accomplished using zero-phase transformation. In the second method, an unconstrained dynamic programming procedure is used. The accuracy of estimating amplitude perturbation by these two methods is evaluated using synthetic and natural voice signals and is also compared with an estimation using zero-padding based time alignment. The unconstrained dynamic programming method is shown to provide accurate estimation of voice amplitude perturbation over a variety of signal conditions.