Brain Atrophy Connected to Mild Hearing Loss in Older Adults

Study results find that people who suffer from hearing loss displayed decreased brain activity on MRI scans while listening and comprehending complex sentences.

Researchers from the Perelman School of Medicine at the University of Pennsylvania conducted a study which evaluated whether hearing loss could accelerate the degeneration of gray matter in auditory areas of the brain; this quickened atrophy could increase the effort required for older adults to successfully comprehend speech.

"As hearing ability declines with age, interventions such as hearing aids should be considered not only to improve hearing but to preserve the brain," reported lead author Jonathan Peelle, PhD, research associate in the Department of Neurology. "People hear differently, and those with even moderate hearing loss may have to work harder to understand complex sentences."

Adults between 60-77 years with normal hearing (in comparison to their elderly counterparts) were assessed in order to determine whether normal variations in hearing ability affected the makeup or functionality of the network of brain regions which are responsible for speech comprehension. The connection between hearing ability and the brain were measured through assessing the brain’s response to sentences, which increased in complexity. Following this test, the researchers then measured the cortical brain volume in the auditory cortex.

Upon reviewing the results, the researchers learned that participants suffering from hearing loss displayed decreased brain activity on functional MRI scans while listening to and trying to comprehend complex sentences. Additionally, participants who were simply poor hearers also were found to have less gray matter in the auditory cortex. These findings indicated that regions of the brain connected to auditory processing may suffer accelerated atrophy when hearing ability declines.

This research, while conducted in older adults, could also have implications for teenagers and young adults, as they are guilty of listening to music or television at increased volumes. "Your hearing ability directly affects how the brain processes sounds, including speech," said Peelle. "Preserving your hearing doesn't only protect your ears, but also helps your brain perform at its best."

The researchers suggested that physicians should keep an eye on the hearing ability of their patients as they age, as some patients who fall within the realm of normal hearing may complain of poor hearing or difficulty understanding complex sentences.

The research appears in the latest edition of The Journal of Neuroscience and was funded by the National Institutes of Health.