About 40 million American adults have some degree of hearing loss, which can impair the way people socialize and respond to events happening around them. Yet despite the prevalence of hearing loss, only about one in 10 people affected by it get hearing aids to improve their conditions.
New research suggests that hearing aids can help a person beyond their hearing — they may also extend a person's life span.
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A study out of the University of Southern California analyzed how using hearing aids affected death rates among a group of adults who had been evaluated for hearing loss. They were followed for 10 years to see whether those who got hearing aids were more likely to live longer.
"We found that adults with hearing loss who regularly used hearing aids had a 24% lower risk of mortality than those who never wore them," said Dr. Janet Choi, an otolaryngologist with USC's Keck Medicine and the lead researcher of the study. "These results are exciting because they suggest that hearing aids may play a protective role in people’s health and prevent early death."
Hearing ability is determined by the health of the cochlea, a spiral-shaped organ in the inner ear that receives sound waves and passes them on to the brain. How well people hear is measured in decibels, which can range from barely audible to piercing and painful.
Typically, sounds below 70 decibels are considered safe while those above that threshold are deemed potentially harmful. A normal conversation is usually around 60 decibels. The average noise level at a concert is about 100 decibels. Sounds above 120 decibels can cause discomfort and pain, with prolonged exposure resulting in damage to the ear.
Many people with mild hearing loss are still able to process sounds, but anything past a loss of 40 decibels is considered a hearing impairment. Some level of hearing loss is often part of aging, but loud industrial environments and habits like listening to loud music also can damage hearing. Certain conditions — like diabetes, high blood pressure and some infections — also can lead to hearing loss.
The USC researchers looked at national data on more than 10,000 adults over 20 years old who had gotten audiometry evaluations — the tests commonly used to measure hearing ability — between 1999 and 2012. The people in the study also had filled out questionnaires about whether they had used hearing aids.
Among the 1,863 adults who were identified as having hearing loss, only 237 of them regularly used hearing aids. Regardless of the severity of hearing loss, those who used hearing aids consistently had a nearly 24% lower risk of death during the study's 10-year period. Notably, those who only occasionally used hearing aids had outcomes similar to those who never used them.
The study did not examine why the use of hearing aids is associated with a lower risk of death, but Choi and her colleagues point to past research that has found the devices decrease the risk of depression and dementia. The researchers believe improved mental health and cognition among those with hearing aids contributes to better overall health and longer life spans.
When to get your hearing checked
Many people are reluctant to get hearing exams — or may be unaware they need one — because hearing loss often advances gradually. One of the most common signs of hearing loss is struggling to follow conversations and routinely asking people to repeat themselves. A steady ringing in the ears, called tinnitus, also may be an indication of hearing loss and the need for an evaluation.
There are various types of hearing tests that can assess damage to the ears, but the most common is a pure-tone test. An audiologist puts the patient in a soundproof room with headphones that deliver noises at varying frequencies and volumes. The test produces an audiogram, which determines the level of hearing loss that patients have.
Hearing aids are generally recommended for people with moderate and higher levels of hearing loss that affect day-to-day activities. Hearing aids amplify sound waves through a microphone and dull other outside noises. They can be adjusted to fit the wearer's precise level of hearing loss.
A common barrier for many people is that insurance companies and Medicare plans typically do not cover the cost of the devices, which can range from a few hundred dollars to several thousand dollars. Many people with hearing loss opt to wait until the issue progresses to a more serious level and they become eligible for a cochlear implant — a surgical procedure used to address hearing loss in one or both ears. Although many insurance carriers cover cochlear implants, using a hearing aid in the interim could provide overall health benefits.
Choi, who was born with hearing loss in her left ear, told CNN that many people avoid using hearing aids because they feel embarrassed by the way they look. After several attempts to find one that worked well for her, she started using a hearing aid in her 30s. Choi said advances in hearing aid technology have made the devices more effective and useful. She hopes the new study will encourage people to consider treatment options more carefully and place more value on their hearing health.
"A lot of people are not using hearing aids because they don't want to look older," she said. "They don't want to be associated with disability, but it really doesn’t have to be that way."