On a robust F0 estimation of speech based on IRAPT using robust TV-CAR analysis

Fundamental frequency (F₀) estimation is important in speech processing such as speech coding, synthesis, recognition and so on. A present F₀ estimation method performs well under clean condition, however the performance deteriorates significantly in noisy environment. As a result, robust F₀ estimation against additive noise is demanded. We have previously proposed F₀ estimation methods based on Time-Varying Complex AR (TV-CAR) analysis whose criterion is the weighted correlation of the complex residual obtained by the TV-CAR analysis, sum of the harmonics for the complex residual spectrum, or so on. On the other hand, E. Azarov et al. have proposed an improved method of RAPT (Robust Algorithm for Pitch Tracking) using an instantaneous harmonics that is called IRAPT (Instantaneous RAPT). The IRAPT can perform better estimation than RAPT. Since IRAPT uses band-limited analytic signal to obtain harmonic frequencies, the complex residual signal obtained by the TV-CAR analysis can also be applied to the IRAPT. In this paper, novel F₀ estimation method using the instantaneous frequency based on the robust ELS (Extended Least Square) TV-CAR residual is proposed and evaluated.