| 摘要 |
A noise sensing method and an intrusion detection device using same are disclosed. The method uses a microphone (2) and comprises processing (50-140) a signal (20) picked up by the microphone to reveal a signal energy change characteristic ( DELTA E/E > K) indicating the presence of a suspicious noise. In one embodiment, every time a new sampling value (xi=j+n) of the signal picked up by the microphone (2) is received, a sampled energy value (Eyn) is calculated (100), the ratio ( DELTA E/E) is calculated (110, 130) of the difference to the sum of the sampled energy value (Eyn) corresponding to the new sampling value and the sampled energy value (Ey(n-1)) corresponding to the previous sampling value, and said ratio is compared (140) with a predetermined constant (K), a noise being sensed whenever the ratio ( DELTA E/E) is greater than said constant. For intrusion detection, an alarm is activated (150-210) when at least two suspicious noises have been sensed, preferably in a predetermined time interval (Tref).
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