Hearing loss to cause subtle changes in the brain

Hearing loss affects more than 60 percent of adults aged 70 and older in the United States and is known to be related to an increased risk of dementia. The reason for this association is not fully understood.

To better understand the connection, a team of University of California San Diego and Kaiser Permanente Washington Health Research Institute researchers employed hearing tests and magnetic resonance imaging (MRI) to determine whether hearing impairment is associated with differences in specific brain regions.

In the issue of the Journal of Alzheimer’s Disease, researchers reported that individuals enrolled in this observational study who had hearing impairment exhibited microstructural differences in the auditory areas of the temporal lobe and in areas of the frontal cortex involved with speech and language processing, as well as areas involved with executive function.

“If so, interventions that help reduce the cognitive effort required to understand speech — such as the use of subtitles on television and movies, live captioning or speech-to-text apps, hearing aids, and visiting with people in quiet environments instead of noisy spaces — could be important for protecting the brain and reduce the risk of dementia.”

The results of the study show that hearing impairment is associated with regionally specific brain changes that may occur due to sensory deprivation and to the increased effort required to understand auditory processing stimulations.

“The findings emphasize the importance of protecting one’s hearing by avoiding prolonged exposure to loud sounds, wearing hearing protection when using loud tools and reducing the use of ototoxic medications,” said co-author Emilie T. Reas, Ph.D., assistant professor at the UC San Diego School of Medicine.

Reference: Hearing loss is associated with subtle changes in the brain; Journal of Alzheimer s Disease, DOI:10.3233/JAD-230767