Think is, the actual real world ones of these I've heard are much more graunchy ... they sound like a beeper running through a blown speaker, or a driver repeatedly crashing their gears trying to find reverse. Krrrrk, krrrrk, krrrrk....<br><br>It's still a less intrusive sound if you're trying to get to sleep and a truck reverses in an otherwise quiet area (the regular beep is, well, like an alarm clock or even a slower paced smoke alarm), yet distinctive and easily identified as a vehicle safety sound, but it's a long way from "fffffst, ffffst, fffffst".<br><br>Really, white noise is the wrong term for it, it's closer to brown, but the broken-up, rough nature of it actually turns it into something else entirely.