I would question the pressure readings from the old stadium. It was so much smaller, I can't imagine that roughly the same number of people didn't make a louder noise in such a more enclosed space. But I am no engineer.

Also, I can more easily imagine that the sound on he playing floor is louder in the UC (nothing blocks sound from reflecting off the roof back to the floor, and maybe even the round shape reflects more sound back toward the court / rink), but I would imagine in the upper deck of seats it was louder back when the overhang was 6 inches above your head!

When you can see it coming, duck!