Researchers assigned 51 normal-hearing individuals attending an outdoor music festival in Amsterdam to wear earplugs or not. During a four-and-a-half hour window, 25 wore silicone earplugs and 26 did not. The time-averaged, sound pressure level experienced during the festival was 100 decibels, according to the the study, published Thursday in JAMA Otolaryngology-Head & Neck Surgery.
Participants, who were an average age of 27, took a baseline hearing test before the concert.
After the concert, they were tested again to show whether there was a loss in hearing. Researchers found that the group wearing earplugs had a temporary shift in hearing of 8%, while the group without earplugs had temporary shift of 42%.
"We have proven that earplugs are effective with loud recreational music," said Dr. Wilko Grolman, study author and professor in the department of otolaryngology at the University Medical Center Utrecht in the Netherlands. "You can see that there is quite a bit of temporary damage to the ears by just going to these venues."
Researchers also found that people who wore earplugs had a lower percentage of tinnitus following sound exposure, 12%, compared with 40% in the unprotected group. Tinnitus is the feeling of ringing in your ears when there's no external sound present. If you're at a concert and you notice a ringing noise in your ears, this is a signal that your ears have been overstressed by the music, Grolman said.
Hearing is only safe in 100 decibels of sound for 15 minutes before there's concern about permanent hearing loss, said Dr. Craig Kasper, an audiologist and chief audiology officer for New York Hearing Doctors.
"Anything over 85 decibels, we start to have some level of concern," Kasper said. "When you start getting to 100, 105, 110, which is not unusual for concerts, there is a significant concern."
Hearing loss, 'an invisible disorder'
The incidence of acquired hearing loss has risen in recent years, according to the study. Dr. Seth Schwartz, an otolaryngologist and director of the Listen for Life Center at Virginia Mason Medical Center in Seattle said greater hearing loss in younger people could be because of exposure to loud noises for extended periods.
"Exposure to recreational noise in younger groups didn't used to be the case. It used to be from military exposures or long-term industrial exposure, and now we are seeing it in kids who aren't in the military and aren't'working in factories," Schwartz said.
Portable music players and headphones can cause even worse effects than concerts because of prolonged exposure, he said.
"The phenomenon of a kid with headphones walking down the street is something that didn't used to exist," said Schwartz. "We know that cumulative small injuries can lead to permanent damage. We aren't telling people not to listen to music, we are just telling them to take care of themselves."
Permanent hearing loss is an important health issue, said Kasper of New York Hearing Doctors, because if it goes untreated, it can lead to isolation, depression, anxiety, and can impact cognitive decline and dementia.
"Hearing loss is kind of an invisible disorder, but it is truly life altering for the person who is impacted," said Kasper.
Although the recent study suggest that earplugs can help to prevent temporary hearing loss during loud concerts, people shouldn't just focus on the booming concerts at an outdoor show, Kasper said.
"We all have to be aware of sound in our environment. It's about the bars we go to with loud music, it's about the recreational activities we are involved in, it's about motorcycles and noisy hobbies," Kasper said.
"There's noise in our environment constantly. Being mindful of potential sound hearing loss is important. We are all exposed to noise, we should all be mindful. This study shows that we should get our hearing tested regularly, and we should wear protection when we are at risk."