We already know pollution from cars increases childhood asthma, and I imagine those pollutants could affect brain development as well.
Edit: Also I would be curious to know how dog barks affect children's brains. Of all the environmental noise, dogs are often the loudest and most jarring, anecdotally.
Motorcycles are absolutely the worst. Even when they drive as slow as possible, to make less noise, they're still noisier than some cars. This is insane. And what's frustrating is that this is considered a feature, not a bug. I don't know how we can get out of that particular culture. I'm not sure electric motorcycles would help at all.
“Loud pipes save lives” is a contentious topic that has some influence on this. Not being noticed in a car is very much less dangerous than on a bike, so it makes sense that more motorcycles are louder as for some of them, that is the goal. People also tend to ride motorcycles because they want to rather than have to, which makes them more likely to tweak their bikes and exhausts.
One of the things I like about driving an electric car is that I can accelerate stupid fast without causing a scene, but I have no interest in an electric motorcycle.
Dogs barking cannot be worse than cars, especially compensators with the pop pop pop engines or tires screeching. Live right by a doggy daycare and several busy arterials
Doggy daycares are generally run by people who love dogs and know how to work with them and make them behave. The problem dogs are the ones owned by people who don't care how they behave and just leave them outside and ignore them.
Edit: Also I would be curious to know how dog barks affect children's brains. Of all the environmental noise, dogs are often the loudest and most jarring, anecdotally.