DUAL-STEP SOUND PATTERN MATCHING

A sound or speech recognition system is made faster by first using data-reduced patterns to find candidates in preliminary testing, and then making a final decision by testing against full-data patterns. Specifically, a signal is transformed to a time-sequence of spectral vectors, which forms a full-data pattern. Then, a predetermined number of vectors representing the beginning or front-end of the signal are duplicated and summed to form a sum spectral vector which is used as the data-reduced pattern for preliminary testing.