Earlier quoted context omitted.
Cities aren't inherently louder than countryside. Car traffic is noisy, but the volume is proportional to the speed. Cars going 30 km/h aren't THAT noisy. You don't hear them through the windows. Cars going 90 km/h are VERY noisy and at that point it doesn't matter if they are electric or not - you mostly hear the tires and the aerodynamics. Using car horns at cities is forbidden anyway, unless there's a crash or a d…
All else being equal, more people = more noise. Since all else isn’t equal, you could design cities that are quieter than the most suburbs. But you could also design suburbs that are quieter than most cities. In the US at least I linked a study that showed cities are far louder on average.
Once you have density high enough you can't live in separate houses. People move to commieblocks or other kinds of multitenant buildings. This shifts everything closer together, makes public transport profitable and having a car becomes optional. These kinds of neighborhoods are quieter than the countryside usually. It looks like this: https://spoldzielnialsm.pl/wp-content/uploads/2018/05/Obecni... https://4.bp.blogspot.com/-ud9-Z0UHVHg/W7-qUjfNT9I/AAAAAAAAi...
Or if you're insane you can mandate enough parking space that this doesn't happen and instead you have highrises in the sea of parking lots.