SPEECH ACTIVITY DETECTION USING ACOUSTIC AND FACIAL CHARACTERISTICS IN AN AUTOMATIC SPEECH RECOGNITION SYSTEM

An automatic speech recognizer only responsive to acoustic speech utterances is activated only in response to acoustic energy having a spectrum associated with the speech utterances and at least one facial characteristic associated with the speech utterances. In one embodiment, a speaker must be looking directly into a video camera and the voices and facial characteristics of plural speakers must be matched to enable activation of the automatic speech recognizer.