The health and scientific community agree that unaddressed hearing loss increases the risk of Dementia among older adults more than any risk factors, including alcohol overconsumption traumatic brain injury, obesity and hypertension combined!
Changing the way people age | the association of hearing loss and dementia
In 2021 Ear Science Institute Australia is committing to reducing the devastating impact on our community of Dementia.
In 2016 Professor Marcus Atlas, Founding Director of Ear Science Institute Australia, announced that researching the connection between hearing loss and Dementia was one of the Institute’s strategic research projects. With no cure or effective treatment currently insight for Dementia, Professor Atlas declared that an expansion of the scope of research was required. Building on the knowledge that hearing loss was one of the largest risk factors for age-related and pathological cognitive decline and Dementia.
Research into Cognition and Hearing Loss
In 2017 the Ear Science Institute Australia self-funded our first research team in this area, resulting in Dr Dona Jayakody and the Australian Cognition and Hearing Loss program. The team have published their findings in leading research publications, with the following significant contributions to the field:
- Showed that the severity of the hearing loss is associated with severe cognitive decline.
- Showed that low to mid-frequency hearing loss is associated with cognitive impairment and depression, anxiety and stress.
- We identified central auditory processing assessments to help identify those at risk of Dementia.
- Showed that cochlear implants could delay cognitive decline.
Results from the Australian Cognition and Hearing Loss project team suggested that hearing loss is a potentially modifiable risk factor for Dementia. In other words, if we treat hearing loss, we can lower the risk of Dementia in some adults. The team are currently undertaking the HearCog clinical trial. This study is investigating the impact of hearing rehabilitation using hearing aids on older adults at risk of Dementia.
Age-related hearing loss is associated with a reduced volume of the brain and changes in brain pathways and metabolic activity of the brain. Studies at Ear Science Institute Australia are currently underway to investigate whether a correction of hearing loss through the use of hearing aids will affect these structural and metabolic changes in the brain. The HearCog clinical trial will explore the cost-effectiveness of hearing loss rehabilitation and the impact of hearing aids on anxiety, depression, physical health and quality of life.
On top of Ear Science Institute Australia’s investment in this work, support has been received from Oticon, one of the largest global hearing aids manufacturers, the Royal Perth Hospital Research Foundation, the Rebecca L Cooper Foundation, and the WA Health Departments Research Translation Program in support of this vital area of research which will benefit our entire community.
Brain & Hearing – focused on treatments for today
The research complements other research programs at Ear Science Institute Australia. The Busselton Healthy Ageing Study is studying the ageing population to determine what drives health outcomes. Our hearing rehabilitation research develops evidence for optimum ear and hearing care. We are active in ageing and mental health research where we focus on mental well-being, which is often affected by hearing loss.
Hearing Therapeutics – focused on curing hearing loss
Ear Science Institute Australia’s Hearing Therapeutics team is tackling hearing from another angle – to prevent or possibly even cure hearing loss. We are one of only two labs worldwide that can convert ordinary human skin cells into stem cells and then encourage them to become hearing (hair) cells. This leading-edge research is in its early phases but shows promise in developing therapies for hearing loss.
Another project uses the science of tissue regeneration which has developed a new product, ClearDrum – an artificial eardrum that will change how damaged eardrums are surgically repaired.
Global and national importance.
The Lancet Commission on Dementia in 2017 and again in 2020 reported that hearing loss is the greatest risk factor for Dementia. The World Health Organization’s World Hearing Report in 2021 highlighted the importance of cognition for the 466 million people globally with hearing loss. The Royal Commission into Aged Care Quality and Safety (2018 to 2021) raised the critical role of hearing health for older adults’ overall health and well-being in aged-care settings.
In 2021 Ear Science Institute Australia is committing to reducing the devastating impact on our community of Dementia through research, education & treatment.
- There is an association between untreated hearing loss and non-verbal cognitive impairment in older adults.
- There is an association between untreated high-frequency hearing loss and non-verbal cognitive impairment.
- Untreated speech and high-frequency hearing loss increases the risk of clinically significant depression, anxiety and stress.
- Central auditory processing is impaired in subjective memory complainers. Some of the people with subjective memory complaints will proceed to Dementia about 10-20 years later.
- Cochlear implants delay cognitive impairment in older adults.
- Use of hearing aids delays cognitive impairment in older adults.
- Untreated hearing loss is associated with emotional loneliness.
References available
References
Jayakody DMP, Friedland PL, Eikelboom RH, Martins RN, Sohrabi HR. A novel study on association between untreated hearing loss and cognitive functions of older adults: Baseline non-verbal cognitive assessment results. Clinical otolaryngology : official journal of ENT-UK ; official journal of Netherlands Society for Oto-Rhino-Laryngology & Cervico-Facial Surgery. 2018;43(1):182-191.
Jayakody DMP, Friedland PL, Martins RN, Sohrabi HR. Impact of Aging on the Auditory System and Related Cognitive Functions: A Narrative Review. Frontiers in Neuroscience. 2018;12(125).
Jayakody DMP, Almeida OP, Speelman CP, et al. Association between speech and high-frequency hearing loss and depression, anxiety and stress in older adults. Maturitas. 2018;110:86-91.
Jayakody DMP, Friedland PF, Atlas MD, Martins RN, Sohrabi HR. Impact of cochlear implantation on cognitive functions of older adults:Preliminary data. Otology & neurotology : official publication of the American Otological Society, American Neurotology Society [and] European Academy of Otology and Neurotology. 2017
Tegg-Quinn S, Bennett RJ, Eikelboom RH, Baguley DM. The impact of tinnitus upon cognition in adults: A Systematic Review. International Journal of Audiology. Accepted for publication April 2016.
Bucks R, Dunlop P, Taljaard DS, Brennan-Jones CG, Wesnes K, Eikelboom RH. The association between hearing loss and cognition in the Busselton Baby Boomer cohort: an epidemiological study of adults born 1946 to 1964. The Laryngoscope. Published online March 2016.
Taljaard DS, Olaithe M, Brennan-Jones CG, Eikelboom RH, Bucks RS. The relationship between hearing impairment and cognitive function: A meta-analysis in adults. Clinical Otolaryngology. Early online Dec 2015. doi: 10.1111/coa.12607
