  It was recently shown that complex cepstrum can be effectively used for
glottal flow estimation by separating the causal and anticausal components of
speech. In order to guarantee a correct estimation, some constraints on the
window have been derived. Among these, the window has to be synchronized on a
Glottal Closure Instant. This paper proposes an extension of the complex
cepstrum-based decomposition by incorporating a chirp analysis. The resulting
method is shown to give a reliable estimation of the glottal flow wherever the
window is located. This technique is then suited for its integration in usual
speech processing systems, which generally operate in an asynchronous way.
Besides its potential for automatic voice quality analysis is highlighted.
