I've got a Honda Accord Hybrid and it certainly doesn't play any noises when it's not running the ICE, regardless of the vehicle's speed. I can still hear the electric motors if I try, but they're not always on either.
Personally, I'm quite happy with a car that doesn't make a ton of useless noise. Not a lot of pedestrians where I live, but plenty of drivers who don't bother to look where they're going. And my car still has the regular horn attached to warn oblivious idiots that they're trying to commit suicide. Quieter environments are better for your health too.