A Time Warping Approach to Fundamental Period Estimation

A time warping approach for estimating the fundamental period of a speech signal is described. The problem of estimating the period of a signal corrupted by background noise is formulated in terms of a minimum error function which defines a matching score between two signal segments and, depending on the error criterion, leads to well-known estimation schemes. To allow for the fact that the speech signal is only a quasi-periodic waveform with time-varying structure from period to period, a nonlinear time warping function is introduced. Using a dynamic programming technique, a computationally simple recursive algorithm is obtained which has the capability of tracking the time-varying period.