Aircraft noise contours—From everything for everyone to nothing for anyone

Aircraft noise exposure contours were originally intended as a tool to facilitate compatible land use in the vicinity of airports. The simple concept was for authorities to use historic data and reasonable predictions for near future demands to create a map that identified areas of high aircraft noise impacts. Municipalities and planners would refer to this map to determine appropriate zoning around the airport, restricting noise sensitive development in high noise exposure areas. With time, different demands and applications of the noise contours emerged. Some stakeholders demanded longer term forecasts to allow for planning farther into the future. Some co-opted contours as a PR tool to suggest reduced impacts on communities. Some began using noise contours as a tool to protect against encroachment. Others began to look to noise contours as a representation of daily acoustic conditions in areas surrounding the airport. In Canada, a lack of oversight and guidance for the selection of inputs parameters for noise models, make it such that noise contours have become a product illustrating whatever their creator intends, lacking objectivity and scientific rigour. This research demonstrates how noise contours can be designed to achieve desired results by modulating different input parameters.