DeKALB — It’s a common sight: students shuffling around college campuses, lugging their 50 pound backpacks with their eyes glued to their phones and earbuds in place. The earbuds, and the music they’re processing, offer a distraction from the discomfort caused by the backpack, as well as people.

But there is a looming drawback to this music-centric retreat — one that could have permanent consequences.

A 2015 World Health Organization review found the use of earbuds has increased by 75 percent between 1994 and 2005. The same study found half of individuals from middle- and high-income countries aged 12 to 35 expose themselves to unsafe sound levels with their portable music devices.

While it may be tempting to pop in earbuds and tune out the world at a high decibel, there is reason to reconsider listening to music at a high volume for an extended period of time.

“It’s harmful because once you get above 85 dBa, which is a measurement of volume…you start doing damage to the hair cells in the ear,” said audiology associate professor Charles Pudrith.

Microscopic hair cells located in the ear, called stereocilia, convert sound vibrations to electrical signals that are transmitted to the brain’s auditory nerve.

Taylor Sellers, senior communicative disorders major, said she was required to take audiology classes, and others that focus on hearing, to fulfill her degree requirements. Before taking those courses, she was one of those people who blasted her music.

“Now I think, and know, that listening to music that loud is so incredibly hurtful to the structures inside your ear,” Sellers said.

Pudrith, who happens to play drums in a rock band, said music is something that’s meant to be enjoyed. But with the volume turned all the way up, high-pitch treble and low frequency sounds are lost in translation.

People experience temporary threshold shift, a short-term reduction in hearing, whenever they expose themselves to high volumes. Those who attend concerts may be familiar with this effect once they step outside of a music venue and notice their hearing is muffled, Pudrith said.

“I’ve definitely gone to concerts and woken up the next day and still had hearing loss from the night before,” said sophomore art major Christine Heinz.

The problem with temporary shift is that once it occurs, hearing will never return to its original state, and it could lead to permanent threshold shift, or hearing loss.

What’s worse, Pudrith said, it is not necessary to experience temporary threshold shift to eventually fall victim to permanent hearing loss. All that needs to happen is a constant exposure to noises over a period of time.

Heinz winced when she learned there’s a term for the hearing loss she experiences after going to concerts.

“It’s definitely something I think will affect me later on in life, especially with how often I go,” Heinz said.

Pudrith said research has shown listening to music at 90 decibels for 40 hours a week will lead to hearing loss. Most people don’t listen to music 40+ hours a week, and portable music devices typically don’t exceed 85 dBa, but individual susceptibility plays a heavy role in hearing loss.

“The fact is once you crank that music so loud that you have to shout over it, that’s when you start rolling the dice,” Pudrith said.

In terms of figuring out how loud you’re actually listening to music, Sellers said NIU’s Speech and Hearing Clinic, 3100 Sycamore Road, has a device that allows graduate students and audiology instructors to recommend how long students should use their earbuds.

“You can actually put your headphones inside the device and play your music at the level you usually do,” Sellers said. “The device will tell you just how loud the music actually is in terms of decibels, and the audiologist or grad students can tell you how long you can listen to music at that level without damaging the structures in your ears.”

But the issue goes beyond simply listening to one’s favorite jam on portable music devices or attending concerts, music festivals or even sporting events. Musicians tend to be at an even greater risk.

Pudrith said tinnitus, a permanent ringing of the ear, is common in musicians who haven’t protected themselves.

“Bob Seger in ‘Turn the Page’ has a line where he says ‘with the echoes of the amplifier ringing in your head,’ ’’ Pudrith said. “That’s not the echoes of an amplifier. That’s tinnitus; that’s a disease.”

Greg Beyer, head of percussion studies at NIU, said he thinks more awareness about long-term hearing loss has better informed musicians about the dangers of repeatedly exposing themselves to high decibels. Since most of his students use custom-made ear moldings, he said he doesn’t receive many complaints from students.

The School of Music contracts with Big Ear, a company that comes to the school every year and creates moldings that are custom designed for students’ ears.

The cost for these moldings can range in price from around $175 to about $197, according to earplugsuperstore.com.

Beyer said the use of higher-end ear moldings works best during rehearsals and performances because the sound has a clean spectrum, unlike disposable ear plugs.

“We are artists in sound, so we are constantly trying to pay attention to the sounds that we produce,” Beyer said. “So when that sound is [covered] by virtue of a soft [ear] plug, that has a negative impact on artistry on the highest level.”

Even though larger venues allow sound more room to travel, Beyer advises people who frequent concerts and festivals to use disposable plugs, especially in smaller venues where loud volumes are more of a hazard.

It’s clear that high volume can be disastrous to a person’s hearing, but Pudrith also warned that hearing loss takes a toll on one’s social relationships.

People will often try to hide their hearing loss.

Constantly needing to strain in order to process what people are saying is an additional cognitive load that leads to embarrassing situations.

“On average, it takes seven years for someone with hearing loss to actually do something about it,” Pudrith said. “They want it hidden because they don’t want people to disrespect their opinion.”

Back to the college students shuffling around campus, drowning themselves in books and music; sometimes you can hear them coming before you actually see them.

“I wish students would think about the repercussions that listening to music that loud has on your hearing,” Sellers said.

Debranae Matthews, freshman political science major, said she tends to reserve loud music sessions for when she’s at home so she can be more aware when she’s walking around in public.

“I just don’t know how [people] can listen to music that loud outside of home,” Matthews said.

For those who crank up the volume to cancel out the chatter they encounter while strolling about, Pudrith said to invest in noise-canceling headphones.

“If you want to listen to music, if you want to hear it all and listen to it all day, everyday, it’s worth the money to get the nice noise-canceling headphones,” Pudrith said. “With the asterisks of make sure you don’t run into a car.”