MICROPHONE APPARATUS, UTTERANCE DETECTOR, UTTERANCE DETECTING METHOD, AND VOICE OUTPUTTING METHOD

摘要

PROBLEM TO BE SOLVED: To realize a microphone apparatus which efficiently detects the uttering interval of a speaker. SOLUTION: An ultrasonic wave transmitting section 111 transmits ultrasonic waves to a speaker S. A sound wave ultrasonic wave receiving section 112 receives mixed waves of the sound waves of utterance of the speaker S and ultrasonic waves which hit the speaker S and reflected back from the speaker S. The received mixed waves are separated into the sound waves and the ultrasonic waves by the LPF121 and the BPF122 of a band separating section 12. A detection circuit 13 detects the signal waves separated as ultrasonic waves and conducts half-wave rectification and smoothing. A differentiation circuit 14 detects the time change of the detected signal waves to extract waveforms corresponding to the movement of the lips of the speaker S. An utterance discrimination section 15 discriminates whether the signal level of the signal waves equivalent to the time change detected by the differentiation circuit 14 exceeds a prescribed threshold value or not and turns ON the voice output of a speaker switch 16 on the basis of the discrimination result. COPYRIGHT: (C)2006,JPO&NCIPI