Researchers from the University of California San Diego and Kaiser Permanente Washington Health Research Institute employed hearing tests and magnetic resonance imaging (MRI) to determine whether or not hearing impairment is associated with differences in specific brain regions to gain a better understanding of the connections.
The Journal of Alzheimer’s Disease reported on 11.21.2023 that those enrolled in this observational study with hearing impairment exhibited microstructural differences in their auditory areas of the temporal lobes and in areas of the frontal cortex involved with speech and language processing as well as other areas that are involved with executive function.
“These results suggest that hearing impairment may lead to changes in brain areas related to processing of sounds, as well as in areas of the brain that are related to attention. The extra effort involved with trying to understand sounds may produce changes in the brain that lead to increased risk of dementia,” said principal investigator Linda K. McEvoy, Ph.D., UC San Diego Herbert Wertheim School of Public Health and Human Longevity Science professor emeritus and senior investigator at the Kaiser Permanente Washington Health Research Institute.
“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.”
For the analysis, 130 participants underwent hearing threshold tests during research clinic visits from 2003-2005, and the respondents subsequently underwent MRI scans between 2014 to 2016. According to the researchers, the results show that hearing impairment is associated with regionally specific brain changes that may occur due to sensory deprivation and 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.
