I recently learned that (at least in the US) those loud motorcycles are actually illegal, and that it is near-standard practise that motorcycles are sold with cheap but compliant mufflers which everyone knows (wink wink) will be replaced with aftermarket loud (but illegal for road) mufflers.

I applaud the research of this young student, showing that noise pollution is not just a nuisance, but a real health concern. Young ears getting permanently damaged is one aspect. Entire neighborhoods losing nights of sleep is another.

Relevant article where police mention that they simply are not given a proper decibel meter: https://patch.com/california/berkeley/ask-a-cop-why-deafenin...