I second the house fan idea. I have new neighbors that must be musicians or something because everyday between two and four they play the same song over and over and over. My husband keeps telling me not to complain but it drives me crazy. The weird part is it isn't even that loud. Our unit has to be completely silent for us to even really hear it, otherwise it's just faint. Sometimes I even put my ear to the wall because I can "feel" that they're playing music. The only thing that completely covers it is the fan. I know I'm being a weirdo about it, but I can't help it.