In 2017, there will be 41 Chicago Department of Aviation(CDA) permanent noise monitors registering aircraft noise throughout the O'Hare International Airport region.
The CDA routinely checks the calibration and performs annual preventative maintenance for every noise monitor in the Airport Noise Management System (ANMS). Noise monitors are sited in consultation with community representatives and based primarily on the criteria outlined in the fact sheet titled Criteria for the Permanent Noise Monitors at O'Hare International Airport.
Once the noise events are collected and downloaded to the CDA's ANMS, they are correlated to actual aircraft operations. The process that correlates noise events to aircraft operations uses defined parameters to match every eligible noise event to specific aircraft operations. Noise events that fall outside these parameters are classified as community noise.