Harmonics tracking and pitch extraction based on instantaneous frequency

This paper proposes a technique for estimating the harmonic frequencies based on instantaneous frequency (IF) of a speech signal. The main problem is how to decompose the speech signal into the harmonic components. For this purpose, we use a set of bandpass-filters, each of whose center frequencies changes with time in such a way that it tracks the instantaneous frequency of its output. As a result, the outputs of the band-pass filters become the harmonic components, and the instantaneous frequencies of the harmonics are accurately estimated. To evaluate the effectiveness of the approach, we apply it to pitch extraction. The pitch extraction is simply accomplished by selecting the correct fundamental frequency out of the harmonic frequencies. The most significant feature of the pitch extractor is that the extracted pitch contour is smooth and it requires no post-processing such as nonlinear filtering or any smoothing processes