Harvard Medical School blog published an article in 2013 on hearing loss and mental decline. Several studies have shown a relationship between losing hearing and losing thinking-power. None of these studies were able to show which came first, or which caused what.
Some of the theories were that the depression and social isolation that is worsened by hearing loss as we get older also causes or worsens memory and thinking skills. Other theories were that the decreased brain stimulation of processing thoughts and ideas that we hear leads to lesser brain function overall.
Now for the good news: new studies have shown an increase in cognitive function and thinking skills when hearing loss is treated. A study in France showed a small group with profound deafness in one ear, treated with cochlear implants and hearing rehab, showed an 80% improvement in cognitive function.
Research into mental decline and cognitive function in older adults is getting some big-money, splashy attention from researchers. They are focusing on finding causes, because in modern medical science, a treatment cannot be truly effective if the cause of a problem is unknown. Cognitive function problems seem to have a wide range of interrelated causes.
It may not be important for researchers to establish a cause and effect relationship between hearing loss and mental decline. If improving hearing through any of the available therapies has the potential to also increase cognitive function and decrease social isolation, it’s worth doing.