Researchers affiliated with UMD’s Brain and Behavior Initiative published a study recently that could dramatically change the way society looks at hearing loss in the elderly.
The journal, entitled “Evidence of degraded representation of speech in noise, in the aging midbrain and cortex,” looks into the loss of the brain’s speech processing capabilities over the course of a lifespan. The researchers found that when older people have difficulty comprehending a conversation, it’s not just a problem with their ears — it’s one with their brain.
Researchers Alessandro Presacco, Jonathan Z. Simon and Samira Anderson performed the study. Presacco was a graduate research assistant in the Hearing and Speech Science department at UMD who has since moved on to complete his post doctorate at the University of California, Irvine. Simon and Anderson are both professors and researchers at Maryland, working in the Electrical and Computer Engineering and HESP departments, respectively.
In the journal abstract, Presacco, Simon, and Anderson outlined their goals and findings. Essentially, the experiment analyzed the effects of background noise on hearing comprehension, and found that it significantly hinders the ability not just to hear someone, but to understand them as well.
In order to complete the study, Presacco, Simon, and Anderson measured brain activity in the midbrain and the cortex of older people while they concentrated on conversations with and without background noise.
“What’s really important about this study is that hearing and sound are not the only things that are critical when you try to understand speech,” Presacco said.
The solution to assisting older people with speech comprehension is more complicated than simply speaking louder, according to Presacco. The centers of one’s brain that process auditory input and separate it from the rest of the noise in a room degrade as people age. This means that when an older person asks someone to repeat the same question four times, he’s not just having trouble hearing: he’s having trouble decoding what’s being said.
“For older listeners, even when there isn’t any noise, the brain is already having trouble processing the speech,” said Simon in an interview for UMD Right Now.
This fact demands a new approach to the research and treatments of hearing loss among the elderly, according to Presacco.
“The novelty of this study is that we were simultaneously studying two different regions of the brain: the midbrain and the cortex,” Presacco said. “It’s two different ways of processing information.”
While the midbrain receives sound, he explained, the cortex is responsible for interpreting it. Similar research has been performed previously on this topic, but this specific study is the first to analyze both involved parts of the brain at the same time.
The significance of this study resonates not only within the scientific community, but among students as well. With this new understanding, students have the knowledge to try to communicate more effectively with their older relatives.
Maya Pasternak, a freshman psychology major, said she is one of many young people whose grandparents have trouble hearing them at family gatherings.
“It really interests me,” she said, “because a lot of people associate hearing with just your ears, and don’t really think about how the brain also impacts a lot of your body functions.”
She said that based on the study, she realizes that she might need to do more than speak louder to her grandparents; she plans to enunciate more and explain her meaning clearly.
While the findings from this study are clearly important, the solutions that should be applied from them are still “not clear cut,” Presacco explained. More research still needs to be done to determine why exactly elderly people experience these comprehension problems in order to take steps to fix them.