A home owner in Cropredy who lives just above the lock gave me the same hassle - I'm always very careful about what time I'm running my engine, especially in Winter (as this occasion was). I dunno why, I think because it gets darker earlier I just think to cut it off at 7pm rather than the guideline 8pm.
Anyway he comes blustering over, knocking on the boat (I was entertaining friends at the time) and starts going off on one about the engine noise. The moorings were 48 hours but had been rented to me by BW as a winter mooring, which he refused to believe lol.... He even went so far as to state 'I know you lot, you have your own little communities and communes and I've got nothing against that, but the amount of boats coming along here is getting ridiculous.' lol
I pointed out to him that I did in fact own a house in the next village and only visited the boat on weekends, but he wouldn't let go.
Eventually I asked him how long he'd lived here before the canal came along and spoiled his peace and quiet and he just left.
Two days later my boat got broken into....