Are Noise-Cancelling Earbuds Safe?

Larry A. Law

Most people are aware that loud sounds can damage the ears. However, doctors are seeing cases where listening at low volume for extended periods can also induce damage. The cochlea is located inside our ears behind the ear drum. It is responsible for turning sound waves into electrical signals that are transmitted to the brain. Prolonged use of earphones stresses and damages cochlea cells. If some of them die, hearing loss can occur. Scientists know that noise-induced damage is dose-dependent and accumulates over time.

What the Science Says

A 2021 study published in the journal Medicine found that teenagers using earphones more than 80 minutes a day in a noisy environment had a 20% higher risk of suffering hearing loss. The risks are nearly 5 times higher than they are for those using earphones for shorter periods of time. Depending on how severe the damage, the individual might experience problems with distinguising sounds, reduced sound sensitivity, tinnitus, and loss of hearing. Keeping earphones continuously in the ear canals can cause a congested, humid environment which can lead to infections. They also create a greater in-ear pressure compared to over-ear headsets. The in-ear earbuds can rub against the delicate skin inside the ears causing micro-tears leading to infection. In addition, the earpieces block most of the canal from outside oxygen. The skin in the ears needs to breathe. Imagine what wearing gloves all the time does to your hands. Dryness and chafing can become a problem.  

Noise Cancellation

These types of noise-reduction earphones and headphones have become very popular as people strive for privacy to shield their music from those around them. Since these earphones silence environmental sounds, their prolonged use can lead to hyperacusis, a condition in which the brain's tolerance for sound decreases so that coughing or typing on a keyboard can trigger a stressful response. Tinnitus and hyperacusis are related as 20% of people with tinnitus also have hyperacusis. People think they are going to protect their hearing, but end up causing their entire nervous system to overreact to normal, environmental sound levels.  

Tinnitus

Studies show that chronic tinnitus is strongly tied to hearing loss and brain hyperactivity. Most tinnitus sufferers have hearing damage and the brain loses sound input at certain pitches. Research suggests that tinnitus is caused by the brain trying to compensate for this loss by recreating the missing sound. People with mild tinnitus hardly notice the phantom sound when background noises muffle the tinnitus. However, the high pitches can be more noticeable when a person is in a quiet environment, wearing ear protection, or using noice-canceling earphones. Anything that blocks the hearing of natural outside sounds can trigger the perception of louder tinnitus. 

Wireless Radiation

AirPods and wireless earphones emit low levels of radiation—the Federal Communications Commission's (FCC) states a limit of 1.6 watts per kilogram body-weight. However, the current guidelines were established in 1996 and were focused on limiting radiation from phones so that they would not heat up the skin. But 30 years later, there is a plethora of wireless devices surrounding us and concerns are growing. Mobile phones are assumed to cause no harm, because they emit non-ionizing radiation which cannot damage DNA. However, non-ionizing radation can cause oxidation inside the cells, leading to inflammation and damage within our cells. Research in cell cultures did find that non-ionizing radiation at levels far lower than set by the FCC could affect DNA and cell function. Some people are more sensitive to wireless radiation. This is known as electromagnetic hypersensitivity and can lead to fatigue, insomnia, tinnitus, and headaches. 

Prevention

Audiologist suggest that people limit earphone volume to a maximum of 85 decibels (same as a food blender or busy city traffic) to prevent hearing damage. They also recommend removing earphones at 2-hour intervals even when used at low volume. People concerned with ear infections should only wear over-ear headphones. Alternatively, use speakers any time you are able. Compared to those who regularly use earphones, those who use speakers did not suffer hearing loss. Eliminating caffeine, stress, infections, and loud noises can all help to reduce tinnitus.