I have traveled extensively in the city, both on legs and bike, and I commute on my bike daily. The noise polution is already at a point where you cannot tell if a small efficient cars is approaching. Hell, you can barely hear a Mercerdes AMG with a massive 6L engine. Unless the goal is to make people aware of a car in otherwise reasonably quite environments, it's pointless to require. That said, Teslas do not have to emit any fake noises in Denmark, and I can STILL hear the tire noise when it's driving past me.