http://sports.espn.go.com/nfl/news/story?id=3095903
"The NFL says no artificial crowd noise was pumped into the RCA Dome on Sunday during the New England-Indianapolis game,"
"CBS has informed us that the unusual audio moment heard by fans during the Patriots-Colts telecast was the result of tape feedback in the CBS production truck and was isolated to the CBS broadcast," NFL spokesman Greg Aiello said Monday. "It was in no way related to any sound within the stadium and could not be heard in the stadium."