I have no idea how it works in London or Miami, but here in Los Angeles many Billions (with a capital B!) have been spent appeasing anti-airport activists over the last 50 or 60 years. Noise studies, preferential runway programs, eminent domain property acquisitions and condemnations... What taxpayers didn't pay for, big airlines did. Of course airlines just pass increased costs on to their customers along with a markup, but that's another story.
As previously noted, much of the actual noise generated has been mitigated by quieter engines over the years, but that just raises the expectations bar higher yet! Where I live, in one of the neighborhoods surrounding LAX, LAWA has been forced to provide noise remediation measures to thousands of residential structures in the area. These measures consist of triple pane windows, ventilation systems so the windows can remain closed and in-wall noise insulation in some cases. Additionally, cash payment has been made to the city of El Segundo to settle "damages". A far cry from just telling local residents to "shut up"!
I've lived in the communities near LAX for 20 years and prefer it to other places I've lived in SoCal. Most people living down here hardly even notice LAX once they are acclimated. As a kid, we lived about 3 miles out just off the extended centerline of the Northern runway. DC-8s, 707s, classic 747s... Now THAT was loud! The average noise level here next to LAX must be about 10 db lower than it is for the hundreds of thousands living within 1,000' of the 405 freeway!
westhawk