SPEECH RECOGNITION METHOD AND SYSTEM WITH IMPROVED VOICE-ACTIVATED PROMPT INTERRUPT CAPABILITY

The present invention provides a system for a voice prompt talkover capability. The system and method include a speech recognizer (36), an echo canceler (24), a delay finder (27) and a utterance extraction mechanism (30). The delay finder (27) determines the propagation delay between outgoing signal and the incoming signal and stores the signal in a delay buffer (23) in accordance with the delay and the filter length of the echo canceler. The echo canceler (24), using the incoming signals, the delay buffer and the delay enhance the incoming signal by removing the echo. The utterance extractor (30) determines the start of an utterance based on energy in the vectors of the LPC buffer (28). Upon the detection of an utterance the utterance extractor (30) initiates the start of recognition and terminates operation of the echo canceler (24) and the prompt play out (14). A recognition result is returned from the speech recognition processor (36) to the application (12).