The study found that over a six year period volunteers with hearing loss showed a 30 percent to 40 percent decline in cognitive ability as compared with those with normal hearing. Researchers were able to directly relate the level of hearing loss to the level of cognitive loss. Those with hearing loss developed a significant cognitive impairment 3.2 years sooner than those with normal hearing.
Johns Hopkins has linked other health related issues to hearing loss in previous studies including a study released last winter that linked hearing loss with an increased risk of falling and a current study linking it with higher brain functions. “Our results show that hearing loss should not be considered an inconsequential part of aging, because it may come with some serious long-term consequences to healthy brain functioning,” says Lin, an assistant professor at the Johns Hopkins University School of Medicine and the university’s Bloomberg School of Public Health.
One possible reason for the ties between cognitive decline and hearing loss is the isolation and loneliness created by loss of hearing. Previous research had already linked those two factors to cognitive problems. Lin postulated that another possible reason is that degraded hearing might require the brain to work too hard at processing sound at the expense of memory and thinking. “The job of the inner ear is to take in sounds and encode them with accurate fidelity before the signal goes to the brain for decoding, but with hearing loss the brain has a very hard time doing that,” Lin says. “If the brain constantly has to expend more resources to decode sound, this may come at a cognitive cost.” There might also be underlying damage that affects both hearing and cognitive processes.
Lin and his team are launching a new study to determine if the use of hearing aids or other devices might delay cognitive decline.
About one-third of Americans between the ages of 65 and 74 have hearing problems and about half the people 85 and older have hearing problems. Yet doctors say only about 15 percent of people who need hearing aids get them.
How do you know if you have hearing loss? It’s recommended that you see your doctor if you:
- Have trouble hearing over the telephone,
- Find it hard to follow conversations when two or more people are talking,
- Need to turn up the TV volume so loud that others complain,
- Have a problem hearing because of background noise,
- Sense that others seem to mumble, or
- Can’t understand when women and children speak to you.
