I'm in this noise 8 hrs a night, 5 days a week.
Add the big IBM high speed printer to that as well.
Although it's 1" foam sound insulation on it's outter panels sure makes a difference when you close the door...
I still don't know why they put that big printer INSIDE the main computer room when it kicks out a lot of paper dust. And since they do no preventative maintenance, whenever something fails, it's usually due to a big buildup of dust.. Hmm... I wonder why...