"Hearing loss is more common as we age and previous research has found it may increase the risk of memory and thinking problems, including dementia, but less is known about how treating hearing loss with hearing aids may impact brain health," said study author Joanne Ryan, PhD, of Monash University in Melbourne, Australia. "Our study followed people with hearing loss, some of whom were prescribed hearing aids and some who were not, and found cognitive scores were similar for both groups. However, we also found that hearing aids were associated with a lower risk of dementia."

Who Was Included in the Research

The study followed 2,777 adults in Australia who were about 75 years old on average and did not have dementia at the beginning of the research. All participants reported having moderate hearing loss, defined as self reported hearing problems, and none had previously used hearing aids.

During the study period, 664 participants received prescriptions for hearing aids. These individuals were asked how frequently they used their devices.

Tracking Cognitive Health Over Seven Years

Participants were monitored for seven years and completed cognitive testing each year. The tests assessed abilities such as memory, language skills, and mental processing speed. Over the course of the study, 117 participants developed dementia.

Researchers compared outcomes between people who were prescribed hearing aids and those who were not. Overall, average scores on memory and thinking tests remained similar in both groups throughout the study. The use of hearing aids was not linked to higher cognitive test scores.

Lower Dementia Risk Emerges

When researchers focused on dementia risk rather than test performance, a different pattern appeared. After accounting for factors such as age, sex, and health conditions including diabetes and heart disease, they found that 5% of participants prescribed hearing aids developed dementia during the study. In comparison, 8% of those without hearing aid prescriptions developed dementia. This difference represented a 33% lower risk of dementia among those prescribed hearing aids.

Ryan noted that the contrast between stable test scores and reduced dementia risk was unexpected. "One factor could be that most study participants had good cognitive health when the study started, reducing the potential for improvement with hearing aids."

Cognitive Impairment and Hearing Aid Use

The researchers also evaluated cognitive impairment, a category that includes both cognitive decline and dementia. After statistical adjustments, 36% of participants prescribed hearing aids developed cognitive impairment, compared with 42% of those who were not prescribed hearing aids. This amounted to a 15% lower risk.

The analysis also showed that more consistent use of hearing aids was linked to a steadily decreasing risk of developing dementia.

What the Findings Suggest

"While we didn't find a difference in cognitive scores, our study suggests that for older adults with hearing loss, using hearing aids may lower the risk of dementia and cognitive impairment, benefiting brain health," said Ryan. "Further studies are needed to understand the ways hearing aids may support memory, thinking and brain health overall."

The researchers emphasized that the findings show an association rather than proof that hearing aids directly prevent dementia.

Study Limitations and Funding

One limitation of the study is that most participants were relatively healthy and had strong cognitive abilities at the start. As a result, the findings may not apply to people with poorer health or existing memory problems.

Funding for the research came from the National Institutes of Health, National Institute on Aging, the Australian government and Monash University.