YuneLee, the research director, said they recruited 35 participants aged between 18 and 41, agreed to undergo functional MRI scans and listen to sentences of different complexity.
After studying, they found something surprising about young people. Some volunteers found mild hearing loss at baseline. They noted that the participants with subtle hearing were similar in their brain activity to the older listeners. Specifically, healthy young people only use the left hemisphere of the brain to process the information they hear. But participants with mild hearing impairment actually showed signs of activity in the left and right hemispheres of their brains. In the latter case, the right frontal cortex becomes active – something that is usually seen only in the elderly.
Lee explained: “it’s not about ears, but about brain and cognitive processes until people are at least 50 years old.”
The leader of the study said that under normal circumstances, healthy young people only use the left hemisphere when engaging in language comprehension tasks. However, as they grow older, they begin to touch the right part of the brain because they are making greater efforts to deal with spoken English. “But in our study, young people with mild hearing loss already have this phenomenon. Their brain already knows that the perception of the voice is no longer what it used to be, while the right side begins to compensate for the left voice.