A Robust Pitch Extraction System Based on Phase Locked Loops

We propose a new scheme for pitch estimation using phase locked loops (PLL). These devices possess desired properties for speech signal analysis, including instantaneous phase detection, and noise robustness. The method is based on a PLL arrange applied to the outputs of a bank of passband filters, each of them tuned to a portion of the spectrum of the signal. PLL devices provide us with robust information about the period of the speech signal harmonics. Combining this information with the spectrum of selected portions of the signal, it is possible to determine a reliable estimate of the period of the whole signal. Performance is evaluated by comparing our system to get_f0 algorithm, with various noise levels. We show that our system largely outperforms get_f0 under noisy speech conditions