In 2011 Johns Hopkins and the National Institute of Aging released a study stating that seniors with hearing loss are more likely to develop dementia over time than those who retained their hearing. Hearing loss, a previously inconsequential part of aging, now becomes an important link in the study of brain health. Dr. Lin found that cognitive abilities in those with hearing loss declined 30-40% faster than those with normal hearing. Greater hearing loss is independently associated with poorer cognitive functioning.
So what’s the connection? Here are 3 theories:
- Cognitive Load – the brain is constantly focused on processing degraded sounds, leaving fewer resources available to encode what one has heard into memory. The theory is that years of taking resources away from the brain functions such as memory will reduce the brain’s resilience.
- Brain Atrophy – Imaging shows that older adults with hearing loss have atrophy (less gray matter) in the brain. These changes are noticed in the temporal lobe, where sounds are received and processed and memory and sensory integration occurs. This area also seems to be involved with mild cognitive impairment and Alzheimer’s Disease.
- Social isolation – People with hearing loss often withdrawal from social activities due to communication difficulties. Cognitive health is dependent on the exercise of body and brain. Being socially isolated is a risk for cognitive decline and dementia.
The question becomes, “Do Hearing Aids Help?”.
There was a small study with 12 elderly participants. The study compared those with normal hearing, hearing loss with and without hearing aids. The group without hearing aids showed the lowest scores on an IQ test while there was no difference between normal hearing and hearing aids users. The study was too small to be a definite answer. However reducing cognitive decline and delaying the onset of dementia even slightly improve the quality of life of millions of older adults.