Are FFEs supposed to growl?

[TedMH]

My car growls a lot. It goes GRRRRRRRRRRRRR. Kind of a low-frequency sort of electric-sounding vibration that I think comes from under the hood. It’s pretty loud.
I haven’t been able to identify cause and effect. It seems to happen most of the time when I open the passenger door after the car’s been sitting in the garage for a few hours or more, but it also happens sometimes when I’m backing out of the driveway or pulling into it. It’s annoying. But it doesn't seem to affect the car’s performance at all.
I could be wrong but it seems to be doing it more and more as time goes by. I’ve had the car since June and it has about 2100 miles so far.
Do your cars growl, too?

 

[davideos]

I think it is your vacuum system. Since the electric vehicle doesn't suck air to combust fuel, there is no natural vacuum system to give power assist to the brakes. I've also heard that other hybrids also have electric vacuum pumps.

It is loud and I don't like it per se, but I don't typically hear it from inside the car. The noise will occur when the vacuum gets low...like when using your brakes...or when you are about to use the brakes...like sometimes when opening a car door. I wish it were quieter...and if there were an aftermarket version that was quieter, I think I'd buy it.

I hope that's what you are hearing. If I misunderstood, I have no idea.

 

[EVA]

You might want to stop by a dealer and check out the sound on another car, just to be sure your car doesn't have a problem. Loud is so relative with this car - things that would normally not bother me, seem insanely loud in this car because it is so quiet.

It is likely the vacuum pump exactly like Davideos said.