Transportation general
Number of People Residing in Areas of Significant Noise Exposure Around U.S. Airports
KEY: dB = decibels; DNL = day-night sound level; R = revised.
a Noise-level contours are graphical representations of noise levels on a map, similar to elevation contours on a topographic map. Noise-level contours are lines that join points of equal sound levels. Areas between given noise-level contour lines would have a noise level between the two contour values. The U.S. Department of Transportation, Federal Aviation Administration (FAA) has identified DNL 65 dB as the...