I shudder. Your loud chewer story triggered a flash back to a coworker clipping their nails (talons) next to me.

About the noise pollution...

Like decision fatique, I think we all have a stimulation budget (buffer). Most of the time, I'm fine. Until I'm not. And my budget (buffer) gets smaller as I age.

Nowadays, I'm completely content to be facing a wall, with earbuds in, so I can tune out and get some real work done.