For those of you watching the NFC Championship today, you're going to hear* about the 12th Man noise more often that 'Belichick vs. Manning' in the AFC Championship.
ESPN Sport Science put together a pretty cool explaination on why the stadium is so loud. It's built like soccer stadiums world-wide, keep ing the noise in the field. Pause the video at 1:22 when they show the Hawks Nest. My first thought was: "that's goofy looking; they could have designed it to fit more people." Then listen to John Brenkus tell us why. Science!