There is a version that does kssssh kssssh kssssh instead. It’s a lot less obnoxious but not standard yet so only a few trucks have it. It’s much nicer.
I forget where I’ve heard this so sorry in advance for the unsourced claim, but I think white noise is much better for humans to place in space. Higher frequency beeps can bounce around much more than a broad spectrum white noise blast.
Anecdotally they tend to travel much less, and generally be less annoying too. I can hear a beeping truck from ages away in my flat, but not once have I thought “god I wish that kssh kssh would stop”.
