Seahawks football fans, and the team, take pride in the Seattle Rattle
"The 12th man"
From the Seattle Seahawks NFL football team website:
“Sunday, November 27th 2005 in a dramatic overtime win, the Seahawks defeated the New York Giants who were called for 11 false start penalties and 3 missed field goals — Courtesy of the 12th MAN’s vocal support. Coach Mike Holmgren dedicated the game ball to the 12th MAN the following day. The ball, now known as the 12th MAN Ball, resides in the Wells Fargo Club.
“With the birth of an NFL franchise in 1976, Seattle fans were no longer starved for their own professional football team. As the Seahawks strengthened, their loud, sold out crowds became known as the 12th MAN.
“The Seahawks average 2.36 false starts a game when playing in CenturyLink Field. There's no question the 12th MAN leads the way for the Seahawks. In fact, it's quite possible they wouldn't have had an undefeated home record in 2012 without their help.
“On December 2, 2013, at CenturyLink Field, against the New Orleans Saints, Seahawks fans registered a decibel reading of 137.6, a Guinness Book World Record.”