Ground-Shaking Noise Rocks N.F.L., and Eardrums Take Big Hit--
"Be LOUD AND PROUD and blow my eardrums out!" one Chiefs fan wrote on Facebook.
The N.F.L. encourages the din.
"Fans know they are going to a football game and not searching for a book at a library," said Brian McCarthy, an N.F.L. spokesman.
But all that noise can come with a serious cost. With peaks for touchdowns and troughs at timeouts, the average volume during an N.F.L. game is probably in the mid-90-decibel range, said Elliott Berger, an acoustical engineer at 3M, which makes protective hearing devices.
Fans accustomed to hollering may scoff at the warnings as nanny-state silliness. But to auditory experts, the danger is very real.
"People think it's cool or funny or whatever, but there is increasing evidence that if your ears are ringing, damage is happening," said M. Charles Liberman, a professor of otology at Harvard Medical School and the director of a hearing research lab at the Massachusetts Eye and Ear Infirmary.
"There's something irreversible going on. It's only going to worsen as you get older."
Liberman's research shows that, even if the immediate effects of noise overexposure subside — the ringing, the muffling, the feeling of pressure — ears do not really recover.
"There is a huge range of ear vulnerability," Liberman said, with some people having "tough" ears and others having "tender" ears. "You don't know till it happens to you."
The potential damage includes not just partial deafness and ringing, but also less common auditory abnormalities such as hyperacusis, an intolerance to sound sometimes accompanied by ear pain.
Just about everyone inside a football stadium on game day — players, coaches and fans — acknowledges that the noise is overpowering.
"People say yeah, man, my ears are ringing," said James Filsinger, 48, a Seahawks season-ticket holder, "but it's always in a fun, upbeat kind of way." Sometimes his friends will say that the game left their ears ringing for a week.
"Most people exaggerate about how long it lasted, but it just goes away," he said.
"Tinnitus may go away or it may not," said Larry E. Roberts, an emeritus professor and auditory neuroscientist at McMaster University in Hamilton, Ontario. "It may go away but then it will come back. The ringing may well get worse with persistent exposure."