Cancellation of loudspeaker words in speech recognition

摘要

A voice recognition system for use with a communication system having an incoming line carrying an incoming signal from a first end to a second end operably attached to a speaker and the outgoing line carrying an outgoing signal from a microphone near the speaker. A first speech recognition unit (SRU) detects selected incoming words and a second SRU detect outgoing words. A comparator/signal generator compares the outgoing word with the incoming word and outputs the outgoing word when the outgoing word does not match the incoming word. The first SRU may be delayed relative to the second SRU. The SRU's may also search only for selected words in template, or may ignore words which are first detected by the other SRU. A signaler may also provide a signal indicating inclusion of one of the selected words in a known incoming signal with an SRU being responsive to that signal to ignore the included one command word in the template for a selected period of time.