Earlier quoted context omitted.
In potentially-dangerous-animal country (e.g. grizzly bears, mountain lions, etc), it could be a safety mechanism...I was told repeatedly you need to make some kind of distinctive noise regularly so they won't get startled by you rounding a bend.
lol. that's like harley riders with unmuffled motors "for safety". On the other hand, I remember being in japan and watching some construction vehicles in tokyo. They were surprisingly quiet. After a while I realized what it was - in the united states all construction vehicles have these annoying "beep-beep-beep" sounds while they're working (for safety). I wonder if one day they can play those only when someone walk…
Should only be while they're backing up. It signals to anyone around that the vehicle is in reverse. At least the ones I'm familiar with.