Explainer: How loud is too loud?

Exposure to air pollution, smoke and lead have serious health risks. Compared to them, what’s the real harm in noise? Can cranking up the volume be all that bad for your health? Actually, a teen’s hearing is more fragile than most people appreciate. 

As an audiologist in the Canadian province of British Columbia, Jan Mayes spent her career helping people whose hearing was damaged by on-the-job noise. It wasn’t just hearing loss. Workers also suffered from tinnitus, a constant ringing or other ghost noises in the ears. Some developed a painful sensitivity to noise called hyperacusis (Hy-per-ah-KEW-sis).  

Hearing damage of any kind can be life-changing. And not in a good way.  

Some people stop going out with friends because they can’t follow conversations. Others stop listening to music because it sounds terrible. Still others quit jobs or hobbies they love because it’s not the same anymore. Hearing aids and coping strategies help, but there is no cure. “Seeing how it impacted [people’s] lives made me a pretty strong advocate against noise,” Mayes says. Now retired, Mayes continues to educate people about the dangers of noise.

The risks 

A lot happens between hitting play and rocking out to your favorite song. First, the sticking-out part of your ears collects sound waves from the speakers on your phone or other device. They funnel those waves to your ear drum, causing it to vibrate. The three smallest bones in the body — the ossicles — amplify those vibrations, and send them through the inner ear and into the fluid-filled cochlea (KOAK-lee-uh).  

Here, tiny hairlike bundles respond to the vibrations. Their movements convey the sound information to the auditory nerve, which relays it to the brain. The brain processes the sound data and, without missing a beat, you hear those first few notes.   

Loud sounds, however, can wreak havoc all along this path.  

Often it damages the auditory nerve first. The brain’s ability to interpret sound can be affected early, too. This kind of damage can cause lots of issues ― sound distortion, tinnitus and hyperacusis. It can also cause trouble understanding speech in noisy environments. Hearing loss happens when the fragile hair cells inside the cochlea die. By that time, there’s already widespread damage. And the body can’t regenerate or replace dead hair cells.  

Loud sounds are harmful in other ways, too. They’ve been linked to cardiovascular effects. These include high blood pressure, heart attacks and stroke. Noise can also lower sleep quality, and impair concentration and academic performance. It’s even been tied to depression and other mental-health issues. 

How loud is dangerous? 

Loudness refers to the intensity of a sound at its source. It’s measured in decibels. Human hearing ranges from zero to 140 decibels, although you don’t want to be anywhere near that high end. The decibel scale is logarithmic. That means each 10-decibel increase corresponds to a 100-fold increase in a sound’s intensity.

A quiet library is about 30 decibels. A typical conversation in a restaurant or office is about 60 decibels. Those conversations aren’t twice as loud as the library ― they’re 1,000 times louder (10 x 10 x 10)! A jet engine is about 130 decibels, or 10 million times louder than a quiet library. Sound that intense can easily damage the hearing pathway. 

So at what decibel level does damage strike? That depends, says Richard Neitzel. He conducts noise research at the University of Michigan in Ann Arbor.  

A nearby explosion can cause immediate and painful hearing damage. Yet permanent damage often can develop at much lower noise levels that feel safe. And it’s not just about the decibels. “We have to think about how much exposure, how often and how long,” Neitzel explains.  

In a review of the science, Neitzel found that virtually all kids would be protected from noise-induced hearing loss if their exposure — as averaged over 24 hours — was 75 decibels or less. That’s about as loud as a vacuum cleaner. The World Health Organization and the U.S. Environmental Protection Agency recommend keeping environmental noise below a 24-hour average of 70 decibels, just to be safe.  

That doesn’t mean a 70-decibel average is completely risk-free. Hearing loss captures only part of the story. Noise-induced problems like tinnitus, hyperacusis and sleep disturbances may occur at lower levels. Mayes also points out that most noise studies have been done on adults, even though kids are considered at higher risk of noise damage. “Human auditory systems don’t finish developing until the late teen years,” she points out.  

In a world filled with noise, how you can protect yourself? Be mindful and think ahead. Don’t crank the volume all the way up. Start at zero and go up to a comfortable listening level ― then stop. Heading to a concert or sporting event? Grab well-fitting earplugs or noise-reducing ear muffs on the way out. If you don’t have to be a noisy environment, don’t. It’s just not worth the risk.