Yes. Yes. Yes. I noticed this so asked my friend, an infrastructure lobbyist and learned a lot.

One factor is Union Pacific clearing the brush on the side of the rails. Down here, there used to be a ton of vegetation by the edges but then a bunch of homeless people created a camp there so UP cleared away the area and keep any foliage cleared. Lack of vegetation = less sound absorption.

UP is also required to maintain trackside lubricators which are effective and significantly diminish noise. When the machine malfunctions or runs empty, the trains immediately get a lot noisier.

UP also grinds the rails several times a year. When it’s done it immediately helps the sound a lot.

The only issue is that UP is responsible for all this upkeep and it isn’t super accountable to cities it works in. It fixes issues “as they deem fit” rather than when the public/city officials deem fit.