Using Post analysis of a noise sample stream in place of noise monitor based thresholds in the detection of aircraft noise

Aircraft noise monitoring systems typically use a fixed threshold on noise monitors for varying times of the day to define what periods of time are to be analysed as possible aircraft noise events. The setting of thresholds leads to significant drawbacks in the continuous measurement of aircraft noise such as:  Missed aircraft noise due to the threshold being above quieter aircraft levels  Non aircraft noise being associated as aircraft noise The experience and capability of personnel that are responsible for the monitoring therefore become paramount in adapting to a continually changing sound environment to ensure reasonable accuracy in reporting aircraft noise. The objectives of the research undertaken by B&K has been to improve the accuracy of recorded aircraft noise and to minimise reliance on personnel, by replacing threshold based measurements with a recursive searching algorithm based on post analysis of a noise sample continuum. The outcome of this work has resulted in an aircraft noise event extraction methodology which mitigates the aforementioned drawbacks of existing systems while minimising the dependency on personnel operating aircraft noise monitoring systems.