Glottal Source Estimation using an Automatic Chirp Decomposition
This work addresses a specific challenge in speech processing for researchers and engineers, representing an incremental improvement over prior methods.
The paper tackles the problem of glottal source estimation from speech signals by extending the Zeros of the Z-Transform (ZZT) method to use a contour different from the unit circle, resulting in a technique that is much more robust to errors in Glottal Closure Instant (GCI) location.
In a previous work, we showed that the glottal source can be estimated from speech signals by computing the Zeros of the Z-Transform (ZZT). Decomposition was achieved by separating the roots inside (causal contribution) and outside (anticausal contribution) the unit circle. In order to guarantee a correct deconvolution, time alignment on the Glottal Closure Instants (GCIs) was shown to be essential. This paper extends the formalism of ZZT by evaluating the Z-transform on a contour possibly different from the unit circle. A method is proposed for determining automatically this contour by inspecting the root distribution. The derived Zeros of the Chirp Z-Transform (ZCZT)-based technique turns out to be much more robust to GCI location errors.