Does hearing loss take a toll on the brain?

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The risks of developing hearing loss and dementia increase as we age. The statistics are rather startling. 
  • One in three people ages 65 to 74 have some form of hearing loss, and that figure rises to one in two for those 75 and older. 
  • One in nine people ages 45 and older say they’ve experienced memory loss, and an estimated 5.7 million Americans are living with Alzheimer’s disease.

Several studies have shown that uncorrected hearing loss gives rise to poorer quality of life and appears to be related to isolation, reduced social activity, a feeling of being excluded and an increased prevalence of depression. It’s also well established that there is an association between hearing loss and cognitive decline, but the mechanisms underlying this connection are not clear. The three main theories are:

  • Common cause: There’s something going on in the brain and nerves that leads to both hearing loss and cognitive decline. In other words, hearing loss and cognitive decline may not be directly linked at all.
  • Sensory deprivation: Difficulty hearing causes you to shift more of your mental resources to listening or understanding speech, stealing away resources for other things like memory. 
  • Social isolation: The social isolation that results from hearing loss leads to cognitive decline. This may occur along with direct effects of sensory deprivation.

While the links between hearing loss and cognition aren’t clear, it makes sense to take steps to protect and maintain hearing to support activities for brain health, such as learning new things and connecting with family, friends and communities.

  • Protect your hearing: Exposure to noise is one thing we can control. Prolonged exposure to loud sounds can damage the cells in your inner ear. When the cells are damaged, it can lead to permanent hearing loss. Sounds below 80 decibels, which is the loudness of a garbage disposal, are generally safe, at least in short doses. Wear ear plugs or earmuffs to bring loud sounds down to a safe volume. Limit the amount of time spent listening to loud music or using loud equipment like lawn mowers or leaf blowers.
  • Get a hearing screening: As we age, we gradually lose some of our hearing ability, which may not be obvious if it occurs slowly. A hearing screening can identify early hearing loss so you can correct it early and take steps to prevent further damage.
  • Visit an audiologist to fit you with a hearing aid or to consider a cochlear implant to treat your hearing loss: a hearing aid is a small electronic device that you wear in or behind your ear to amplify sound. Cochlear implants deliver sound signals to the auditory nerve that the brain interprets as sound for individuals with moderate-to-profound hearing loss. We are beginning to see studies that suggest that use of amplification devices in patients with severe hearing loss potentially results in improvements in cognitive functions. It’s also plausible, though unproven, that earlier intervention for people with hearing loss may stall cognitive decline. Ongoing studies are investigating this, including a study at The Ohio State University Wexner Medical Center.
  • Participate in auditory rehabilitation: working with a speech-language pathologist can help you listen and communicate better, and it’s possible that these interventions may improve cognitive functions. Moreover, rehabilitation can help restore some hearing deficits and improve participation in social activities.

Aaron Moberly is a neurotologist in the Department of Otolaryngology at The Ohio State University Wexner Medical Center. Christin Ray is an assistant professor of otolaryngology.

 

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