Frequency warped ARMA analysis of the closed and the open phase of voiced speech

Abstract

Frequency-warped analysis techniques are attractive in many speech applications since they have a clear connection to human hearing. In this paper we propose a warped version of a pole-zero analysis obtained from several periods of voiced speech. We approach the estimation of the coefficients associated to the poles and zeros by minimizing a cost function, which is based on the 'warped' reconstruction error. The results reinforce our previous work letting us an extension of the initial equations by introducing the concept of auditory perception in the formulation. This facilitates an improvement in the analysis of the phases associated to consecutive periods. With the experiments we address several objectives. First, to evaluate the importance of the time extension due to warping. Second, to obtain an optimum warping factor from a reconstruction error point of view. Third, to study the behaviour of our analysis with the period length. And fourth, to study the distribution of the error in frequency. Our results indicate that the use of warped techniques is beneficial in speech analysis.