Researchers from the Perelman School of Medicine at the University of Pennsylvania recently completed a study showing that declines in the ability to hear may accelerate gray matter atrophy in auditory areas of the brain and increase the listening effort necessary for older adults to successfully comprehend speech.
In a pair of studies, researchers measured the relationship of hearing acuity to the brain, first measuring the brains response to increasingly complex sentences and then measuring cortical brain volume in auditory cortex. Older adults (60 to 77 years of age) with normal hearing for their age were evaluated to determine whether normal variations in hearing ability impacted the structure or function of the network of areas in the brain supporting speech comprehension.
The studies found that people with hearing loss showed less brain activity on functional MRI scans when listening to complex sentences. Poorer hearers also had less gray matter in the auditory cortex, suggesting that areas of the brain related to auditory processing may show accelerated atrophy when hearing ability declines.
In general, this research suggests that hearing sensitivity has cascading consequences for the neural processes supporting both perception and cognition. Lead author Jonathan Peelle, PhD, research associate in the Department of Neurology, says, “Your hearing ability directly affects how the brain processes sounds, including speech. Preserving your hearing doesn’t only protect your ears, but also helps your brain perform at its best.”
The research appears in the Journal of Neuroscience and was funded by the National Institutes of Health.