Full-Scale Near-Field Acoustic Holography for Reduction of Annoyance and Disturbance

ABSTRACT:Noise levels of military jet aircraft have significantly increased as the power of the engines has increased creating a community noise issue around military airfields. Current noise monitoring requirements only measure sound pressure levels which do not correlate to human annoyance / disturbance. Sound Answers plans to apply their extensive Sound Quality background to establish new acoustic time- and frequency-based metrics which will correlate to human perception for annoyance/disturbance. Then, Sound Answers staff will apply their Noise & Vibration troubleshooting methods to evaluate various acoustic array technologies to identify the most efficient / cost effective method for cascading the new annoyance metric results to actual design features of the jet engine in an effort to reduce the annoyance levels of the new aircraft. The final deliverable will be a Matlab-based toolbox integrated into Sound Answers Time Frequency Analyzer Core (TFAC) software and will also be embedded in current commercial software packages used for acoustic monitoring at airports.BENEFIT:- Civil and Military Aircraft manufacturers, who can specify noise requirements to engine manufacturers in light of annoyance in the far-field. - Jet engine manufacturers, who can implement better near-field noise test procedures to validate their product, increase their noise diagnostic capabilities and be more effective in identifying areas of noise reduction - Government agencies, in the US and abroad, who can apply the new annoyance/disturbance metrics to improve the power of their Community Noise Impact tools.