Real-zeros in pitch detection

The real-zero-crossings of a speech signal are developed as the basis for estimating the pitch period of voiced speech. The speech signal is pre-processed by a small, special-purpose system which establishes thresholds for rejection of silent periods and produces measurements of the time interval between real-zeros of the signal. These measurements allow a reduction of computational complexity which permits an autocorrelation estimate of pitch and voiced-unvoiced decisions to be made in near real-time using a mini-computer. The pitch estimates are shown to be robust.