The annoying version of that is in Roma St train station in Brisbane, Australia, they play a super high-pitched noise -- the theory is only young people can hear it, and after a while it starts to really annoy. The issue with it, is if you have good hearing and aren't a young "hoodlum" it'll drive you crazy if you're hanging around having a smoke, or meeting friends. I'm unsure if it's still there, it was a couple years ago now.