| 摘要 |
Method and apparatus to determine if a sound produced by an event is due to glass breakage comprises producing a plurality of frequency band-limited signals from an electrical signal characteristic of the sensed sound and characterising the event by comparing at least one characteristic value derived from the band-limited signals with a relatively narrow range of values and with a relatively wide range of values. The event is characterised as a glass-breakage event if the value is within the narrow range, as a non-glass breakage event if the value is outside the wide range and as an event to be further analysed, to determine whether glass breakage has occurred, if the value is within the wide range but outside the narrow range. Sound characteristics in three frequency ranges and four time periods, associated with various aspects of glass impact and breakage, are used in the determination and a variety of measurements and comparisons are performed on the band-limited signals, their integrals and derivatives to validate, exclude or further process an event. |
