New methods of pitch extraction

Three new methods will be described for the extraction of the fundamental pitch from a speech signal. These are: 1) spectrum flattening followed by a minimum phase correction to synchronize harmonics 2) spectrum flattening followed by auto-correlation, and 3) nonlinear distortion followed by autocorrelation. The last two methods will be shown to be exceptionally rugged, in that they can tolerate a considerable amount of high-pass filtering and additive noise with little degradation in performance.