Arrowhead always gets props for the loudest stadium in the NFL, all the time. It even gets louder than any of the domes. One LSU fan said the only place which can get as loud as Tiger stadium is Arrowhead, so my pride and opinion isn't totally off.
I find myself having to defend what I say, when I'm not arguing.

I love you SEC guys and girls, I envy you, but don't think just because the Chiefs are not college football that they don't know how to get loud. They can rock the house, especially with the second largest professional stadium in america, and one of the few without Club seats. They have premium seats, but they're all outside, and only about 5,000 of the 80,000 people, and it's just for the rich people to cheer their butts off, which they still do. I got preseason tickets to club seats and basically it's the same except you get your own bar, and you can get something to eat other than a hotdog. There's only one other stadium I can think of that doesn't have luxury club seating, and that's Candlestick or whatever it's called nowadays (3com?).
SMSUBear