The problem is that the driver might have so many beeps, that they decide to ignore yet another beep. I suppose a beep that sounds very different would get the

The problem is that the driver might have so many beeps, that they decide to ignore yet another beep. I suppose a beep that sounds very different would get their attention, like for pilots in plane cockpits. A terrible stand-up comedian suggestion would be to reuse the plane's "retard, retard!" for parents who forget their kids...