Actually it's because of the litigious society we live in, that no one pays attention to the beeps.  Every vehicle now has multiple flashing lights, and beeping, and neon yellow paint.  Because everything has these safety features, people have become accustomed to them so they are largely ignored.  Same thing will happen to this white noise thing over time, at which time someone will think up a new noise, or they will go back to regular beeping.