Track would opened in 1960 and no houses were within earshot back then so they have all been built afterwards. The 1964 aerial pic shows just a few houses but the 1968 shows almost as many as current.
http://www.historicaerials.com It's hardly a new noise nuisance, maybe just new people in those houses.
I think moving the nitro pits closer to the houses and cutting down 3/4 of the trees was a very bad idea. Turning the track end for end would have been a good idea but nothing became of that.