Visitors encounter a wall of noise

ford and has been tormenting Seahawks coach Pete Carroll ever since.

Finally, throw in that early, unexpected lead and — voila! — a near-perfect sound storm.

“Obviously, they were jacked up last night,” said Fred Gaudelli, the innovative producer of “Sunday Night Football” on NBC. “But in my mind, it’s one of the underrated sports towns in America. Actually, the special challenge there is always to convey how loud it actually is.

“We knew that going in, plus we knew the 49ers were the team their fans hate the most. So at Wednesday’s regular ‘brainstorming session,’ we turn to our head audio engineer and said, ‘How do we make viewers understand you can’t hear the person next to you most of the time, even if he’s yelling?’ We wanted to be ready.”

Gaudelli knows what can happen to a team that ventures into Seattle without preparing for the wall of noise.

In 2005, the visiting New York Giants collected 11 false-start penalties in a single game there. The Carolina Panthers once practiced for a game there by dragging loudspeakers down to the practice field and simulating the sound of a jet engine. If that sounds over the top, it is, by about 18 decibels. Jets are routinely measured at around 130, Century Link’s best is only 112.

Gaudelli and his crew hatched a plan to demonstrate that by having sideline reporter Michelle Tafoya speak into a microphone as the sound reverberated, then take a step back and try again. When they ran through it before the game, he had a stadium staffer simulate the crowd noise over the PA system. At the point Tafoya’s words were drowned out the system was cranked to 50 percent of volume.

“So I asked the guy, is it really going to be that loud? He looked at me,” Gaudelli chuckled into the phone, “and said, ‘Double it.’ ”