ONCC officials attributed the aircraft noise reduction around O’Hare International Airport to quieter aircraft fleets; greater adherence to the nighttime O’Hare Fly Quiet Program, which is designed to reduce aircraft noise over residential areas through the use of preferred departure runways and flight paths; and other technological and operational improvements.
The City of Chicago’s Airport Noise Monitoring System (ANMS) measures noise at 30 sites around O’Hare, and the ONCC reports those results to its members and the public on a monthly basis.
The largest decline was reported at site #3 in Bensenville, where the 2006 Day-Night Average Noise Level (DNL) was 61.0, down 6.3 from the 67.3 DNL recorded when the baseline readings were taken in 2000. Other large improvements were recorded in Melrose Park (-5.2), Northlake (-4.9), Schiller Park (-4.4), Park Ridge (-4.0), Elk Grove Village (-3.1), Des Plaines (-2.7), Mt. Prospect (-1.9), and Arlington Heights (-1.6).
DNL is a noise measure used to describe average aircraft noise levels over a 24-hour period, typically an average day over the course of a year. It penalizes aircraft operations that occur between the hours of 10 pm and 7 am by 10 decibels to account for increased annoyance when ambient noise levels are lower and people are trying to sleep. It is currently the accepted measure for aircraft noise analysis.
A decibel level of 70 is about equivalent to the noise from a vacuum cleaner at 10 feet. A level of 60 is like normal speech at 3 feet, and a level of 50 like a dishwasher in the next room.
ONCC Chairperson, Arlington Heights Mayor Arlene J. Mulder, said the report affirms the effectiveness of the Chicago Airport System’s noise mitigation programs and the ONCC’s multifaceted approaches to address aircraft noise issues. “We are glad to see continuing progress in our efforts to mitigate the noise coming from O’Hare air traffic. We still have much work to do, but we truly appreciate the efforts and contributions of many other stakeholders in realizing these noise decreases, including pilots, controllers, airline and maintenance managers,” Mulder said.
The O’Hare Noise Compatibility Commission (oharenoise.org) began working in 1996 to bring together the parties that are most able to reduce aircraft noise with representatives of communities affected by aircraft noise in a partnership to address jet noise at its impact and sources.
The Commission's current membership includes the villages of Arlington Heights, Bartlett, Bellwood, Elmwood Park, Franklin Park, Harwood Heights, Hoffman Estates, Maywood, Melrose Park, Mount Prospect, Niles, Norridge, Palatine, River Grove, River Forest, Rosemont, Schaumburg and Stone Park; and the cities of Des Plaines, Northlake, Oak Park, Park Ridge, Rolling Meadows and Chicago; Cook County; and school districts 59 (Elk Grove Village, Des Plaines, Arlington Heights, Mount Prospect), 63 (Des Plaines, Niles, Morton Grove and Glenview), 80 (Norridge), 81 (Schiller Park), 84 (Franklin Park), 84½ (River Grove), 85½ (River Grove), 86 (Harwood Heights), 87 (Berkeley, Northlake, Bellwood), 88 (Bellwood, Melrose Park, Stone Park) 89 (Maywood, Melrose Park and Broadview), 214 (Elk Grove Village, Des Plaines, Arlington Heights, Mount Prospect, Rolling Meadows, Prospect Heights, Wheeling, Buffalo Grove), 234 (Norridge, Harwood Heights), 299 (Chicago Public Schools) and 401 (Elmwood Park).