Hmm.. Have to wonder something...
How long have they owned their house, and what were the traffic flows like before they changed them to the previous setup they had? It's possible they fell into the same situation homeowners in Las Vegas did, and are whining about it.
For those not in the know, there used to be absolutely nothing west and south of the 19 and 25 departure corridor out of LAS for a good 7 - 8 DME. So there really was no complaint about noise. Then housing developments started to pop up, and people moved into them, and now they are complaining about noise from departure paths that were established there... for YEARS before those homes were even thought of, let alone built.
It could just be lack of common sense. If you're living near an airport, or under the departure or arrival paths of planes, EXPECT NOISE.