Representation of speech signals using Hartley group delay function

Abstract

This paper presents an alternate representation of phase information in speech signals using Hartley transform. Hartley Group Delay Function (HGDF) is computed on similar lines of Fourier Group delay function. Cepstral smoothing is applied so as to reduce the spiky nature of the group delay functions. The smoothened HGDF (SHGDF) is reported to have better resolution in group delay spectrum. A speaker verification system is designed as an application for the proposed signal representation. SHGDF is then presented as input to feed forward neural network. Performance curves using MFCCs, MODGFs and proposed SHGDF as features for the neural network are compared. It is found that the SHGDF functions provide better average performance for the speaker recognition system.