The main noise from cars is tire noise. But if traffic moves slowly enough (which it does in a Chinese city during rush hour), you won't hear much. Even since

The main noise from cars is tire noise. But if traffic moves slowly enough (which it does in a Chinese city during rush hour), you won't hear much. Even since 2002 I've had to dodge quiet e-bikes in Beijing. They just sneak up on you without any noise, and they have a lot more momentum than a human powered bike.