Maybe you heard about Sunday’s Seahawks versus 49ers game, and how Seattle broke the record for loudest stadium? Or maybe you didn’t hear because you were deafened by the record breaking 12th Man roar.

A couple of 49ers fans definitely heard and now they are making their own noise. Judy Spelman wrote a letter to the editor of the San Francisco Chronicle, complaining that the 49ers would have won Sunday’s game if their team could have heard their signals. She told KIRO’s Dori Monson she wants the Seahawks banned from playing at home if The 12th Man keeps up the noise.

“Consider the possibility of a petition to the NFL to see if other fans feel disturbed by the unfair advantage that Seattle seems to have when you’re at home,” Judy said. “Maybe a petition that shows broadband fan support for fairness on the field.”

But is all that noise solely The 12th Man’s doing, or does it have to do with the architecture of CenturyLink?

“Well, it was built to be a great home field advantage,” says Paul Greisemer, principal architectural director at AECOM, the firm that designed CenturyLink.” The fact that it is loud is really kind of a result of a number of things that came about just through the design. It’s on a very small site, comparatively to other stadiums, and because of that we had to compress the building very tightly. Fans are closer to the field than they are in most any NFL stadium today. So that combined with the desire to have a large roof covering, so fans are protected, really kind of combined the greatest of convergence of storms into a great environment.”

Beyond the design, the materials used to build the stadium also contribute to the roar.

“It’s a metal roof so it naturally is a very reflective surface. As is the seating bowl which is largely concrete. So there are a lot of those materials that are serving as sound mirrors, if you will, and bouncing the sound right back.”

I asked Paul what where the loudest part of the stadium is.

“Luckily, it’s right on the field, it seems, from all of the false starts that the visiting teams experience. The way the roof is angled, and the way the bowl captures all the sound that goes backwards and focuses it back towards the center of the stadium, you’re pretty much going to get the maximum affect right at the players.”

As we can now read in the Guinness Book of World Records, CenturyLink is the loudest stadium in the country. Paul says no one even comes close and other cities definitely covet that honor.

“We get calls all the time from various clubs and from stadiums as far as, ‘What can we do to improve our game environment?’ As far as sound goes, people would love to have what Seattle has. I think they realize that it’s pretty tough to replicate what Seattle has. So they’re all looking for maybe their own way.”

So is Judy The 49er Fan’s anger rooted in jealousy? Would she be this upset if 49er fans were just as loud?

“I don’t think it is sour grapes at all,” Judy told Dori. “I think what we’re saying is you put a whooping on the field because you had an unfair advantage. If you couldn’t hear your signals and we could hear ours, you would have lost and we would have won. We’re a great team, Seattle is a great team. If you can’t hear your signals, you can’t play the game.”

It will be interesting to see if the NFL acknowledges Judy’s concerns, since according to Paul, the NFL has praised CenturyLink’s unique design and fan experience.

“It’s great when stadiums can develop their own persona. They’re iconic for the city that they’re in. CenturyLink does that better than most or any that I know. Even the NFL recognized CenturyLink recently in the top 10 things in the NFL. CenturyLink was in that top 10 for best home field advantages ever. Not just in the current NFL, but ever. You know, we’re very proud of that.”