Perseption of noise
It is not the noise itself that is the problem but the way in seen by the person that it is irritating.
You will note that above light aircraft and motorcycles are the focus of this because those complaining about the noise can't see the reason why people should want to partake in motorcycling or recreational aviation. Added to this some just don't like to see people enjoying themselfs whatever the recriational activity, for these people the fact that legislation has reduced considerably the noise from modern motorcycles and aircraft is not the issue, it is just they don't like you enjoying yourself.
I at one time lived on the final approach at Wycombe air park and was regularly accosted by those drumming up support for restrictions on flying because of noise, I had to point out to these people that the sound of lawn mowers drowned out the noise from the aircraft and that maybe they should start by taking action against the source of the loudest noise.................the reply to my comment was that lawn mowers are essential and light aircraft are not ! With logic like that I could ban every thing from opera to football on grounds of noise pollution.
The trouble is that for some obsessive people the noise is just a way of justifying a way of stoping other people enjoying themselfs, a number of years back I was asked by a model flying enthusiast if I would help him launch a radio controlled glider with a bungee. He had taken to flying the glider because the local councelers had band powered model flying on some days of the week because of noise complaints. It was not long before the police turned up because someone had complained about the noise, clearly they had seen a model aircraft, and decided to stop the fun, a noise complaint being the logical way to do this.
Fortunately having inspected the noisy glider the police decided to caution the person complaining about the noise for waisting police time...........following this inccident the complaints about noise from model aircraft almost stopped.
I do have some sympathy for those on the ground, there was one guy who regularly practiced aerobatics over the same location on weekday evenings, it is hardly suprizing the locals did not like this, as a body of aviation enthusiasts we should fly consideratly and if we do so it will only be the fanatics that complain, the problem is to isolate them from the people who sign the activists petitions just to get them off the doorstep.