A new study published in the International Journal of Audiology found that the brain’s ability to process sound starts to slow as early as middle age.
The research, led by Vishakha Rawool, Ph.D., CCC-A, associate dean for research in Georgia Southern University’s Waters College of Health Professions (WCHP) and professor in the Department of Clinical Sciences, offers insight into a common frustration for many adults: being able to hear sounds clearly but struggling to follow fast conversations, especially in noisy environments.
To understand what happens inside the brain’s hearing pathways, researchers compared two age groups: young adults between ages 18 to 27 and middle-aged adults between 45 to 59.
The team measured how quickly the brain and the ear work together using a middle-ear reflex that automatically contracts when it hears loud sounds. By tracking how this reflex responded to a rapid series of clicks, they determined how efficiently the brain’s auditory system processed sound.
“We wanted to catch the very first signs of change,” Rawool said. “By the time someone has significant hearing loss, they may already be dealing with social isolation, anxiety or difficulty at work.”
The results showed that the middle-aged group’s brain response was slower than that of the younger adults. This difference suggests that the brain’s “hearing speed,” or how rapidly it can process fast sounds, naturally begins to decline when a person reaches middle age.
“Using an objective measure that is not affected by cognitive decline, the results show that the central auditory system starts to slow down by midlife,” stated Rawool. “This slowing may require greater listening/cognitive effort, perhaps unconsciously, while listening to fast speech, reverberant speech and speech in noisy surroundings.”
The study also affirmed that this slowdown was not related to the ability to hear sounds, but instead it was linked to changes in how the brain itself processes sound. According to Rawool, loss in hearing speed can leave people feeling as though they are trying to read a sentence with missing letters.
“We need to stop thinking of hearing health as something that only matters when you’re 70,” Rawool said. “We should be checking in on ‘hearing speed’ in our 40s and 50s.”
Rawool and her team hope that publishing this research will lead to training programs or therapies that strengthen the brain’s auditory processing in adults ages 45 to 59, potentially helping to reduce listening fatigue and communication difficulties later in life.
The research also suggests the need for creating the best listening environments, such as quiet spaces with low reverberation, for all listeners to reduce fatigue.
“If you feel exhausted after a long day of listening, it’s not just in your head,” she said. “Your brain may simply be working harder—and that’s something we can begin to address.”
The study was partially supported by West Virginia University’s Grace Clements Communication Sciences & Disorders Research Endowment Award.
