SANTA CLARA The man spearheading the effort to make Seattle's CenturyLink Field a nightmare of noise for the 49ers grew up a 49ers fan.
Joe Tafoya is from Pittsburg and played at Pittsburg High and Arizona before playing six seasons in the NFL, two as a Seahawks defensive end.
Two months ago, Tafoya wondered whether the famously robust vocal chords of Seahawks fans could set a record. So he hopped on the Internet, found the site for Guinness World Records and fired off an application.
Naturally he figured that Sunday, when the Seahawks host the 49ers, would be the best opportunity to test his theory. A monitor from Guinness will be at the game to see if the noise can reach 131.77 decibels, which would make it the loudest crowd ever recorded. The current record holders, the fans of Galatasary, a Turkish soccer team, hit 131.76 decibels during a match against rival Fenerbahce on March 18, 2011.
Tafoya said the Turkish fans set the record with the aid of vuvuzelas and other noise-making devices. Those aren't permitted in NFL venues, meaning the Seattle fans will have to do it by clapping their hands, stomping their feet and blowing out their voice boxes.
"That's similar to a jet engine," Tafoya said of the noise level. "In order for us to break the record, it's going to have to be extremely loud."
How loud? 3M is passing out earplugs before the game.
The 49ers have had problems with Seattle's noise even when the rivalry wasn't at its current white-hot level and when there was no Guinness record on the line. In December, they were penalized twice for delay of game and they burned all three timeouts in the first half as the Seahawks raced out to a 28-6 lead.
The 49ers lost 42-13, the most lopsided defeat since Jim Harbaugh became coach. Harbaugh, however, was even-keeled Wednesday, saying the 49ers would approach the game like any trip.
The 49ers practiced in front of concert-size speakers that blasted music from The Black Keys and Guns 'N' Roses. But they do that before every road game and even some home games.
"It's very loud," Harbaugh said of CenturyLink Field. "They do a very good job of bringing a lot of noise up there. And not to compare it to anywhere else, but it's right up there."
Said running back Frank Gore: "It's real loud. Hopefully we can go in there, start fast, and we can make their fans be quiet."
When he retired from the NFL, Tafoya started a marketing company, which has partnered with Volume 12, a Seahawks fan group, for the record attempt.
It spent $8,000 to secure the Guinness monitor for Sunday's game and also hired a sound engineer and rented a piece of equipment called a Class 1 precision measuring instrument that will record every decibel generated by the crowd.
"It's not something you can pick up off the shelf," Tafoya said.
Opposing players have suspected the Seahawks pump in artificial noise through the stadium speakers to enhance the crowd noise. Tafoya said the Guinness monitor would not be able to detect shenanigans like that, but he said he's been assured by the Seahawks they do not use the speakers when the game is being played.
"That would be illegal," Tafoya said.
Tafoya said he realized how jarring the noise was inside Seattle's stadium when, as a player, he emerged from the tunnel during the NFC Championship Game following the 2005 season.
"There was an unbelievable energy and noise that just kind of gets in your soul," he said. "Right away, you understand that this environment is either going to be very supportive or very hostile. The fans thought they were part of that win, and they were."
How does he feel about his role in increasing the volume and the difficulty level against his hometown team on Sunday?
"They had their chance," he said with a laugh. "(Steve) Mariucci and his group didn't think I was worth it, so their loss."