EVs make artificial sound outside at low speed for that reason. I'm not sure but I would assume this is government mandated.

This is different though, this here is for the user to be able to judge how much the cpu/motor is working. And yes, not only do some EVs offer you fake indoor noises, a lot of gas cars also do it as engines get more silent/sound worse to meet modern regulation. https://www.youtube.com/watch?v=4lQPc9VXBzk