| 摘要 |
<p>An acoustic alarm recognition unit (1, Fig.1) comprises a microcontroller (100, Fig.1) having a sound input (110, Fig.1). In a learning mode the microcontroller processes S602 sound data representing an acoustic alarm received at the sound input to produce a test measure S604 of the acoustic alarm and to determine a test value S606 based thereon. In a live mode it processes S610 the received sound data to obtain a live measure thereof and to compare S620 the live measure with the test value to determine S630 if the acoustic alarm is sounding. Processing the sound (Fig.2) may include analogue-to-digital conversion (by ADC 116, Fig.1), band pass filtering, rectification, descriptive statistical analysis (e.g. calculating a time-varying frequency property) and may be carried out for multiple time periods (e.g. sliding windows). The unit may be used to within door control mechanisms, control panels, radio sounders or vibrating pillow alarms.</p> |
