Research Shows Hearing Loss Can Affect the Brain
"Hearing loss" 30 to 40 percent of people 65 years of age and older suffer from this debilitating sensory disability, and approximately 85 percent of these go untreated.
The loss of hearing can be frustrating as it worsens, which can sometimes lead to depression. In fact, the chances of experiencing psychological problems in an individual with hearing loss is four times more likely than in someone with normal hearing.
A recent study by Johns Hopkins University and the National Institute on Aging suggests that over time older Americans affected with hearing loss are more likely to develop dementia than individuals with no loss of hearing.
Researchers looked at data from the Baltimore Longitudinal Study on Aging (BLSA) begun in 1958 to track the health of men and women. The new study concentrated on a group of 639 people who experienced testing for hearing and cognition between 1990 and 1994. While roughly 25% of the individuals were affected with hearing loss during this period, none of them had developed dementia.
The subjects were given examinations every one or two years. When tested in 2008, it was found that dementia had developed in 58 of the participants. Even after examining other risk factors like high blood pressure, diabetes, age and sex, a strong correlation remained between hearing loss and dementia.
While it was concluded that subjects with hearing loss were more likely to develop dementia, the chances were exponentially greater as the level of hearing loss increased from mild to moderate to severe.
Frank Lin, M. D., Ph. D, who is an assistant professor in the Division of Otology at Johns Hopkins served as the study leader. "Researchers have looked at what affects hearing loss, but few have looked at how hearing loss affects cognitive brain function," he stated. "There hasn't been much crosstalk between otologists and geriatricians, so it's been unclear whether hearing loss and dementia [were] related."
Lin and his team suspect two possibilities for the link between hearing loss and dementia. Either a common disease pattern triggers both problems, or the strain of having to decipher sounds over time might overwhelm the brain. They also suspect that social isolation - sometimes a result of hearing loss - might lead to dementia, as it is a known risk factor.
It is hopeful that the findings of Dr. Lin and his team may shed light on the importance of intervention when it comes to hearing loss and that more individuals will seek treatment. In addition to hearing aids as a valuable resource, a new product has recently been developed that can boost the performance of a hearing aid.
A hearing loop is a thin copper wire that sends electromagnetic signals and is mounted around the periphery of a room. The signals are received by a small telecoil that can be installed into hearing aids and with the press of a button, a hearing-impaired person can hear as well (or better) than a person who is not impaired. These loops have been installed in a growing number of public buildings.
While the development of the hearing loop is beneficial to people with hearing loss, more research is needed to investigate even better ways to improve hearing and possibly prevent or slow the development of dementia.