I live 600 ft from an Amazon DC in Northern VA. There will be FOURTEEN DC complexes within 1/4 mile of our development.
It ain't fun.
This Business Insider video has a really good example of the sound https://www.youtube.com/watch?...
One thing that makes this really hard is that sound waves, like water waves, bounce. During the last big snow, it changed the sound profile so much that I could literally feel my hardwood floor vibrate. Normally it's low end grunt noise but that was even lower.
Because of this, regulations need to 'over protect' residential areas, because literally every home will have a unique sound level. Unfortunately, that's going to be a hard sell against Million$ in DC political money.
And worse, *multiple* DCs nearby, the sound is additive. Two 50 db speakers produce more than 50 db in volume. If the ordinance is 55 and the additive is 57 - who do you blame? In a river, we measure each polluter at the source - So far, getting sound meters installed AT the DC property lines has been a no go.