As someone who both works in a warehouse around machines that beep when backing up and who welcomes change, progress, and science; I don't think that the white noise is a better option. there are a lot of sounds on a lot of machines that sound like "shhh." While the science is obviously sound (no pun intended) in the way of white noise being harder to drown out and being easier to hear at lower volumes; it would appear that they didn't account for one realm of science and that's the sociology/psychology of what sound is actually alerting to humans. A 1khz beep naturally grabs your attention. White noise is everywhere and humans learn to just tune it out.