Spectral correlates of glottal waveform models: an analytic study

Abstract

This paper deals with the spectral representation of the glottal flow. The LF and the KLGLOTT88 models of the glottal flow are studied. We compute analytically the spectrum of the LF-model. Then, formulas are given for computing spectral tilt and amplitudes of the first harmonics as functions of the LF-model parameters. We consider the spectrum of the KLGLOTT88 model. It is shown that this model can be modeled in the spectral domain by an all-pole third-order linear filter. Moreover, the anticausal impulse response of this filter is a good approximation of the glottal flow model. Parameter estimation seems easier in the spectral domain. Therefore our results can be used for modification of the (hidden) glottal flow characteristic of natural speech signals, by processing directly the spectrum, without needing time-domain parameter estimation.