My Zoe has a noisemaker, it sounds like a Zombie. Pull the right fuse and it's no longer an issue. Mine is off always, and I can tell you so far I have not run, or almost run anybody over.
You get some comments about "wow, that's creepy" when you crawl off, but you have to be going very slowly to be making next-to-no noise. Even with no engine noise, there is an awful lot of other stuff wirring around, cooling and heating stuff. Noisy transformers etc.
I have had plenty of pedestrians oblivious to my petrol car with its noisy sports exhaust pootling behind them . As in reality, petrol engines don't make an awful lot of noise either when crawling.
The noisemaker in the Zoe turns off at 18mph, because it's redundant. Most the external noise from cars aren't engines, it's tyres. Just go into the country a bit and listen out for traffic, aside from obnoxious motorcyclists, the noises you hear is the thrum of rubber on tarmac.