HearCog is a two-year randomised control trial of hearing loss and dementia being undertaken by Ear Science Institute Australia (Ear Science). The study is investigating whether hearing aids can delay or arrest cognitive decline.  

A landmark report, The Lancet Commission on dementia, prevention, intervention and care, in 2017 showed hearing loss was a priority for tackling dementia. However, to date no definitive studies have shown that treating hearing loss will change the trajectory of cognition. 

Dr Dona Jayakody, Audiologist and Research Lead for the Cognition and Hearing Loss Project at Ear Science, developed the trial concept in 2015. “My research found that hearing loss is associated with cognitive impairment/dementia so I was interested in finding out whether this could be delayed or arrested by treating hearing loss,” said Dr Jayakody. “Current data suggests hearing loss accounts for 8% of the modifiable risk factors of all cases of dementia.” 

HearCog is a randomised, controlled 24-month clinical trial investigating whether the correction of hearing loss using hearing aids could decrease the 12-month rate of cognitive decline among older adults at risk of dementia. Taking part are 180 older adults with hearing loss and mild cognitive impairment. 

Although the research results are yet to be finalised, several important issues have emerged during the recruitment phase and as the study commenced. Participants reported the significant impact of hearing loss on loneliness, social isolation, communication and quality of life. Several reported suicidal ideations at the thought of developing dementia. 

Co-lead of the study, Associate Professor Andrew Ford added: “Many things have emerged from this study that we didn’t expect, such as participants wanting to improve their hearing health but having no one to go home to hear with or learn from.” 

Study participants completed comprehensive assessments of their hearing, cognitive skills, mental and physical health and lifestyle. They were all expertly fitted with hearing aids, with some participants waiting a year to receive theirs, as part of the randomised intervention design of the study. 

They also completed magnetic resonance imaging (MRI) and fluoro-deoxy-glucose (FDG) positron emission tomography (PET) imaging. The results of this imaging will allow researchers to gain more insight into the structural and functional changes of the brain as a result of using hearing aids. 

The trial also explores the cost-effectiveness of the intervention as well as the impact of hearing aids on anxiety, depression, physical health and quality of life. 

Preliminary findings are expected to be published in the middle of 2024. 

For further information, visit https://www.earscience.org.au