| 摘要 |
PROBLEM TO BE SOLVED: To provide a sound block detector by which a sound block can be surely detected even in the sound signal of a low S/N. SOLUTION: The sound signal collected by a microphone 11 and amplified by a line amplifier 12 is converted to a digital value by an A/D 101 and stored in a storage part 102. After a noise is removed, the digitized sound signal improves the S/N by taking a self-correlation in a short time and when the period of the S/N greater than a threshold is continued for a prescribed period, the sound block is decided. Further, in order to surely detect the head and end of the sound block, the preceding part and the following part of the sound block are forcibly opened for a predetermined period. Besides, in order to prevent the threshold from becoming too great by storing noises, the prescribed multiple of a moving average value for the predetermined period of a non-sound block is successively updated as a threshold. COPYRIGHT: (C)2003,JPO
|
