I found out about "noise gate" quite by accident last night while watching some news clips from KDKA-TV2.
They have an excellent site: http://kdka.com/sports
The clips are in Macromedia Flash 7. Very tidy.
It was an abomination that the game was not played without the enhanced noise for Indy.
This is not totally unlike picking out a golfer in match play (one on one) and allowing the spectators to yip, hoot, and scream while he is in his backswing........... then remaining silent for the other competitor!
Huh! That's the first I'd, uh, heard of it.
I'm not inclined to jump on board with conspiracy theories. But if even one incident is established, it'd call all of Indy's home field victories in the "Perfect Season" into question.