A Method for Low-Delay Pitch Tracking and Smoothing

In this paper, a new method for pitch tracking is presented. The method is comprised of two steps. In the first step, accurate pitch estimates are obtained on a sample-by-sample basis by updates of the signal statistics with an exponential forgetting factor and subse- quent numerical optimization. In the second step, a Kalman filter is used to smooth the estimates and separate the pitch into a slowly varying component and a rapidly varying component. The former represents the mean pitch while the latter represents vibrato, slides and other fast changes. The method is intended for use in applica- tions that require fast and sample-by-sample estimates, like tuners for musical instruments, transcription tasks requiring details like vi- brato, and real-time tracking of voiced speech.