Earlier this fall, Seattle Seahawks fans at CenturyLink Field broke the world record for loudest stadium crowd with a skull-splitting 136.6 decibels.
That volume, as the Seahawks’ website boasts, hits the scale somewhere between “serious hearing damage” and “eardrum rupture.”
Just weeks later, Kansas City Chiefs fans at Arrowhead Stadium topped that number with 137.5 screaming decibels of their own.
The measuring method used for the Guinness World Record has an edge of gimmickry. That A-weighted peak measurement, reached for a split second near the measuring device, displays the highest possible readout.
For a vulnerable ear, however, game-day noise isn’t just harmless fun. With peaks and troughs, the decibel level of noise reaching a typical spectator averages in the mid-90s, but for a longer time.
Such noise is enough to cause permanent damage and to increase the likelihood of future damage.
“The extent to which hearing-related issues get so little attention is amazing and troubling,” said M. Charles Liberman, a professor of otology at Harvard Medical School and director of a hearing research lab at the Massachusetts Eye and Ear Infirmary.
“Many people are damaging their ears with repeated noise exposure such that their hearing abilities will significantly diminish as they age, much more so than if they were more careful,” he said.
Ears are deceptive. Even if they seem to recover from the muffling, ringing and fullness after a rousing game, they don’t really recover. It’s not just the tiny sensory cells in the cochlea that are damaged by noise, Dr. Liberman said, but also the nerve fibers between the ears and the brain that degrade over time.
Too much noise causes not just partial deafness, which usually starts with trouble hearing in background noise, but an assortment of poorly-understood auditory abnormalities. These include tinnitus, or ringing in the ear, and hyperacusis, a sensitivity or intolerance to sound, sometimes with ear pain.
“People who complain of hyperacusis often point to a specific overexposure to noise as being the thing that initially put them over the edge,” Dr. Liberman said.
In some cases, “hyperacusis patients cannot even have a normal-voice-level conversation with their family because that can create pain lasting for days at a time,” said Bryan Pollard, president of the nonprofit group Hyperacusis Research. “Noise-induced pain creates an extreme loss of quality of life.”
Damage from noise is cumulative; it is tough to separate the effects of a lifetime of recreational, environmental and workplace noise. Assessing noise risk is complicated, too, with an unpredictable interplay of volume, duration and susceptibility, which varies enormously across the population.
A sensory loss is hard to detect because people don’t know what they are not hearing. Over time, hearing only becomes worse — never better.
Some people with tinnitus report more than just a ringing or buzzing — they suffer from swirling, oscillating, multitonal noises in their head sometimes accompanied by sensations of pressure. There is no treatment beyond coping strategies.
According to the American Tinnitus Association, around two million Americans are so debilitated by tinnitus that they cannot function on a day-to-day basis.
Unlike awareness of other pernicious health hazards, such as smoking and suntanning, awareness of harmful noise is minimal.
“Everyone has their own benefit-risk equation, but this is an area where education is lacking,” said Jennifer Tufts, an associate professor of audiology at the University of Connecticut who is president of the National Hearing Conservation Association.
At a loud event — assuming someone has no pre-existing ear problems — ear damage is largely preventible with properly-worn earplugs or protective earmuffs.
The Hearing Speech and Deafness Center of Seattle got wind of the record attempt at CenturyLink Field and seized on a “teachable moment.” Volunteers for “Operation Earplugs” distributed 30,000 pairs of earplugs donated by 3M. (The company also donated 36,000 pairs in Kansas City, when the fan group Terrorhead Returns organized its record attempt.)
Earplugs, however, might not be sufficient for people with already-injured ears. “Got tinnitus and hyperacusis, and it got worse after attending a game despite wearing earplugs,” one fan wrote on Facebook. “I don’t think most people are aware of the consequences.”
Another wrote: “I’ve learned to live with the tinnitus, but if it gets worse I’ll go crazy.”
Harvard’s Dr. Liberman compares the increasing knowledge about those disabling consequences with “the rising consciousness about repeated concussions and brain damage” in football players, which may lead to dementia at an early age.
“You don’t notice it right way,” he said. “You shake it off and you think you have recovered, so you do it again. Changes in brain function add up slowly.”