For a while I worked for a company who did contracts for the FAA for noise abatement studies as part of their Part 150 Airport Noise Compatibility Planning. We used computer modeling to determine noise maps, using existing scheduled flights and aircraft types at that airport. A B737-200 was noisier than a B737-800 for example. Maps like this were developed:





We also modeled the departure tracks, or noise abatement tracks for the airports studied. Here at Newark for example, if you look at the departures to the south, you can see the turn westward just S of Elizabeth. Houses within a certain db level were purchased by the FAA and torn down, and houses further away received noise proofing.


Here is a link to the Newark noise maps: Final Noise Exposure Map Report - EWR Airport


While today's jets are quieter than older ones, they still make noise. Also, Part 150 studies aren't done very often, maybe every 10-15 years so the data to allow a change to a noise abatement procedure takes a while. The biggest issue is that changing a departure moves the noise from one set of people to another - it is very politically charged and generally can't get done. So the noise abatement procedures don't change.


Here's a list from the FAA of big airports and links to their noise abatement pages: https://www.faa.gov/airports/environ...exposure_maps/