1. A method for Chinese speech pitch extraction, comprising: pre-computing an anti-bias auto-correlation of a Hamming window function; for at least one frame, saving a first candidate as an unvoiced candidate, and detecting other voiced candidates from the anti-bias auto-correlation function; and calculating a cost value for a pitch path according to a voiced/unvoiced intensity function based on the unvoiced and voice candidates, saving a predetermined number of least-cost paths, and outputting at least a portion of contiguous frames with low time delay.