Single Event Noise Data


​Installed in 1996, the Airport Noise Management System (ANMS) enables the Chicago Department of Aviation (CDA) to monitor the amount of noise generated over the communities surrounding O'Hare by the aircraft operating at the Airport. The ANMS collects, analyzes and processes data from a number of sources of information including a network of 33 noise monitors around O'Hare, FAA radar data, weather data and noise complaints. For more information on the system, click here​.

The CDA’s noise monitors record noise events based on threshold exceedance. Each noise event starts at the time the noise level exceeds a decibel threshold, typically slightly above the background or ambient noise level, and ends at the time the noise level returns to the threshold. For every noise event (aircraft or community) recorded by the ANMS, the CDA is reporting three noise metrics.

These three noise metrics are industry standard metrics and are calculated at the noise monitor. The metrics include the Lmax (Maximum Sound Level), the Leq (Equivalent Sound Level)​, and the SEL (Sound Exposure Level). The Lmax is the peak noise event in decibels, the Leq is the average sound level for the event in decibels, and the SEL is the average sound level for the event in decibels accounting for both intensity and duration. SEL takes all of the energy under the line in a sound pressure level versus time graph and compresses it to a 1 second value.

The single event noise data is uploaded to this webpage on a weekly basis as a .txt file. Each file contains: the monitor Site ID, the start date and time of the event, the date and time of the peak noise for the event, the duration in seconds of the event, and the Lmax, the Leq, and the SEL of the noise event in decibels.

The following data is preliminary data and is subject to change. Preparation​ of the monthly noise data includes quality assurance and quality control procedures for the data and reports. The final data will be incorporated in the monthly ANMS Reports.

April 16 to April 22, 2017​
April 9 to April 15, 2017​
April 2 to April 8, 2017​
March 26 to April 1, 2017​
March 19 to March 25, 2017​
March 12 to March 18,2017​
March 5 to March 11, 2017
February 26 to March 4, 2017
February 19 to February 25, 2017 ​
February 12 to February 18, 2017
February 5 to February 11, 2017
January 29 to February 4, 2017
January 22 to January 28, 2017
January 15 to January 21, 2017
January 8 to January 14, 2017
January 1 to January 7, 2017​
December 25 to December 31, 2016
December 18 to December 24, 2016
December 11 to December 17, 2016
December 4 to December 10, 2016
November 27 to December 3, 2016
November 20 to November 26, 2016
November 13 to November 19, 2016​
November 6 to November 12, 2016
October 30 to November 5, 2016
October 23 to October 29, 2016