Hearing Loss and Cognition
Age related hearing loss
Age related hearing loss is a complex interaction of peripheral (inner ear), central auditory and cognitive changes that occur with age. While hearing loss resulting from inner ear changes plays an important role, studies controlling for this have found that older adults still have greater difficulty understanding speech in noise than do younger adults with equivalent hearing, indicating that other age-related auditory processing deficits occurring higher up in the auditory system undermine speech perception. In other words, our brains, as well as our ears, become hard of hearing as we age. When we’re young, the brain does a masterful job of filtering, sorting and making sense of the information that flows through our senses every day. This ability becomes diminished as we age, causing problems with multiple inputs and fast inputs; i.e., our ability to understand speech in noise, and our ability to follow fast speech.
Hearing loss and memory
Understanding and following conversation requires working memory. We need to hold earlier words in memory while we analyze others in order to make sense of them. We then compare new information with what we know to assign meaning. When signal quality is poor (hearing loss, noise, accents) more effort needed to process and understand, engaging working memory more to fill in gaps. More resources also needed for processing information leaves fewer available for storing it into memory. Increased listening effort increases cognitive load, often rendering people with hearing loss exhausted at the end of the day.
Hearing loss and social isolation
Social events can be exhausting for people with hearing loss. Social isolation is Key factor in healthy aging, so it affects mental and physical health and well-being. Effects of Age-related hearing loss on ability to communicate and socialize effectively are commonly accepted and profoundly important. Social engagement in older adults is key determinant of overall morbidity and mortality. People with untreated hearing loss likely to withdraw from social interaction; Loneliness and isolation can directly affect physical health. Effects of Age-related hearing loss on ability to communicate and socialize effectively are commonly accepted and profoundly important. People with untreated hearing loss likely to withdraw from social interaction; Loneliness and isolation can directly affect physical health.
Physical decline
Growing body of evidence of its association with both cognitive and physical functional decline. We know that isolation, dementia and falls are among the leading causes of admission to long term care facilities and we also know that hearing loss is related to these serious concerns, along with increased rates of hospitalization and health care utilization.
Impact of hearing loss on cognition
Both hearing and cognitive loss increase with age but there is more hearing loss in those with dementia. Research shows strong evidence of association between hearing loss and cognitive impairment. Older adults with untreated hearing loss are more likely to develop dementia and the more severe the hearing loss, the greater the risk. Age-related hearing loss is independently associated with dementia and accelerated cognitive decline.
Hearing aids and cognition
Using hearing aids appears to reduce the excess risk from hearing loss. 35% of dementia cases can be attributable to 9 modifiable risk factors, with hearing loss the largest at 9%. Education, hearing loss, social isolation, cardiovascular disease, metabolic and psychiatric factors, diet, lifestyle. If hearing loss is considered a risk factor, then management could potentially postpone the onset or slow the progression of dementia. Hearing aid use may mediate cognitive decline through reduced social isolation and depression or increased cognitive stimulation.
After a decade researchers found that: “Hearing Aids Can Slow Rate of Cognitive Decline by Nearly Half “.
Hearing assessment should be then part of any dementia diagnosis. Canadian dementia care guidelines recommend assessing and recording hearing impairment in primary clinics as a dementia risk factor.
