Recent research at Johns Hopkins University in Baltimore has found that 20 percent of Americans 12 and older already have some level of hearing loss. Hearing loss, especially starting at such a young age is troubling in itself. But what is especially disturbing are the links recently discovered between hearing impairment and the risk of developing dementia.
“My wife says I never listen to her. At least, I think that’s what she said.” –Anonymous
Signs of hearing loss can be very subtle, especially at its outset. Maybe that is why hearing loss is a much more widespread problem than most people realize. In fact, recent research at Johns Hopkins University in Baltimore has found that 20 percent of Americans 12 and older already have some level of hearing loss.1
Hearing loss is defined by the World Health Organization as the point at which daily communication starts to become impaired. That means the 48 million Americans determined in the study to have hearing loss in one or both ears are experiencing at least some difficulty just having regular conversations when there is background noise. And approximately 30 million people, or one in eight Americans 12 or older, have that level of hearing loss in both ears.
The researchers based their findings on an analysis of the 2001 through 2008 National Health and Nutritional Examination Surveys (NHANES). Participants had been given hearing tests, so this data was more realistic than previous findings of between 21 and 29 million Americans with hearing loss that were based purely on self reporting or only reflected the results for certain segments of the population.
The study uncovered some unsurprising facts, such as that hearing loss gets more prevalent as we age. But the amount is astounding: with each subsequent decade, hearing loss practically doubles. Also, women and black people are less likely to experience hearing loss at any age than the rest of the population. While the researchers cannot pinpoint the reasons for that, it may have something to do with genetics or lower sensitivities to noise-induced damage.
In a separate study that took place at Bloomsburg University in Pennsylvania, scientists determined that college students tend to listen to the music on their iPods and other listening devices at levels that are dangerous to their hearing.2 The scientists surveyed 384 students, of whom 92 percent used listening devices.
Men and minority students of both genders were the worst culprits, frequently listening to their music at between 75 and 100 percent of maximum volume. They don’t actually seem to realize just how loud the volumes they are listening to are, either. The students raise the volume levels when in a noisy place to make listening more comfortable, then leave the levels there once their hearing has adjusted. When they turn the devices back on later, they are shocked at how loud the music is playing. More than 75 percent of the participants use ear buds, and previous studies have found that their use is associated with louder listening volumes as well.
Hearing loss, especially starting at such a young age is troubling in itself. But what makes the issues we’ve been discussing especially disturbing are the links recently discovered between hearing impairment and the risk of developing dementia. A study that took place last year at Johns Hopkins University found that those participants with a mild amount of hearing loss, who might have trouble following a conversation in a noisy atmosphere, had almost twice the risk of developing dementia as compared to those with no hearing loss.3 For those with moderate hearing loss, who may experience difficulty keeping up with a conversation even in a quiet setting, that risk was three times greater. And for those with severe hearing loss, who typically must rely heavily on lip-reading, the risk was five times higher. Even after the researchers took into account other factors that are associated with risk of dementia including diabetes, high blood pressure, age, sex and race, hearing loss and dementia were still strongly connected.
No one is suggesting that hearing loss directly causes dementia. On the other hand, it is true that a significant portion of the brain is used to process auditory stimuli. Having a conversation with someone exercises significant and vital sections of the brain. Active listening stimulates large areas of the brain optimizing auditory and language processes. With un-treated hearing loss this connection weakens, and it becomes more difficult for a hearing impaired individual to process and understand what is heard even when using hearing aids. In effect, the brain gets much, much less exercise.
So it’s clearly essential to get your hearing tested on a regular basis and use hearing aids if you do have some level of hearing loss. But try to do what you can to prevent that loss in the first place. Stay out of super noisy environments such as clubs and rock concerts as much as possible. The ringing in your ears that happens when you leave those places means damage has been done to your hearing. It will heal, but the damage accumulates over time and eventually becomes permanent.
When you plug into your iPod, keep the volume set low. Try starting it at the lowest and just increase to where you can listen comfortably. You are less likely to push it up too high if you start out very quietly. And when you can, skip the device altogether. Listening with others through speakers will help keep the volume down so any conversations taking place can actually be heard.
1 Lin, Frank R.; Niparko, John K.; Ferrucci, Luigi. “Hearing Loss Prevalence in the United States.” Arch Intern Med. 2011;171(20):1851-1852. (Accessed 26 January 2012.) < http://archinte.ama-assn.org/cgi/content/short/171/20/1851 >.
2 Doheny, Kathleen. “Hearing Loss Bugs 1 in 5 Americans.” WebMD. 15 November 2011. (Accessed 26 January 2012.) <http://www.webmd.com/news/20111114/1-in-5-americans-have-hearing-loss>.
3 Lin, Frank R.; Metter, E. Jeffrey; O’Brien, Richard J.; Resnick, Susan M.; Zonderman, Alan B.; Ferrucci, Luigi. “Hearing Loss and Incident Dementia.” Arch Neurol. 2011;68(2):214-220 . 7 April 2011. <http://archneur.ama-assn.org/cgi/content/short/68/2/214>.