Our study aimed to explore the contribution of transportation activities to environmental noise levels near an international airport. A-weighted equivalent and maximum noise levels (LAeq, 6hr; LAmax, 6hr; LAeq, 1hr) were monitored at six different locations characterized by their varying proximity to transportation sources. The values for LAeq, 6hr were in the range of 55.3 to 75.6 dBA, and LAmax, 6hr were 4.1 to 9.1 dBA higher than their respective LAeq, 6hr values. Standard deviations were low across all sites and indicators (0.20-1.83 dBA). We found that at each site measured, the WHO’s noise exposure guidelines of 55 dBA were exceeded, including sites located in residential areas or near a school. In one residential area near the airport (but away from other transportation sources), noise levels were 63.1 dBA. In another residential area closer to the airport, the contribution of airport noise to environmental noise was estimated to be 72.3 dBA, which is roughly as high as the contribution of two other transportation sources (highway and railway) in this area. In proximity to the Montreal International Airport, noise levels may have been elevated by airport operations and by noise from flights, the latter of which likely has a weaker effect on, and the former of which is unlikely to contribute to, noise levels at locations farther from the airport. At farther distances however, aircraft passages raised noise levels to a greater extent above those levels when no flight was passing, reflecting a sporadic quality of aircraft noise.