Airport Noise Management System (ANMS)

Aircraft Noise Reports

The report summarizes noise measurements from each of 32 permanent noise monitors located around O’Hare Airport in Day-Night Average Sound Levels (DNLs). DNL is a 24-hour time-averaged sound exposure level with a 10-decibel (dB) nighttime (10 p.m. to 7 a.m.) weighting to account for lower background noise levels during nighttime hours.