How Hearing Loss and Memory Loss Are Connected

Asking family members to repeat questions, turning up the volume to hear the television, and trying to fill in conversation gaps when spending time with friends are all signs of hearing loss and can make a person feel awkward. 

Beyond the frustration and social embarrassment that comes with it is another, more profound concern: memory loss. Researchers are discovering a strong connection between hearing loss and diminished cognitive function.

How Does Hearing Work?

The hearing process involves the three parts of the ear, which work together with the brain to help a person understand speech or make sense of sounds.

• Outer Ear- The pinna, the visible portion of the ear, catches the sound and directs it down the ear canal to the tympanic membrane, known as the eardrum. The sound causes the eardrum to vibrate.
• Middle Ear- Vibrations from the eardrum transfer to the ossicles, the three small bones that make up the inner ear, which convey sound to the oval window that separates the middle ear from the inner ear.
• Inner Ear– From the oval window, sound enters the snail-shaped organ known as the cochlea. The fluid inside the cochlea moves and stimulates 25,000 nerve endings to generate the electrical impulses that travel along the auditory nerve to the brain, which interprets these signals.

What Causes Hearing Loss?

Hearing loss is the inability to hear sound. It ranges from partial, where some sound can be heard, to complete, where no sound can be heard.  It has many causes, some of which are hereditary or the result of injury or disease. 

The most common types of hearing loss are noise-induced hearing loss, caused by continued exposure to loud noises, and presbycusis, age-related hearing loss.  Both tend to have a gradual onset and are usually considered a mild hearing loss.  

Despite its name, mild does not mean that it can be ignored. Instead, it refers to the loss of hearing being at the lowest level on the scale used by hearing professionals. Hearing Associates of Las Vegas can provide an evaluation to determine your level of hearing loss.

Hearing & the Brain

Studies on seniors have shown that hearing loss increases a person’s risk of dementia. The National Institute on Aging defines dementia as “the loss of cognitive functioning — thinking, remembering, and reasoning — to such an extent that it interferes with a person’s daily life and activities.” Understanding the link between hearing loss and dementia can help people make informed decisions about their auditory health.

Hearing and Thinking

One of the brain’s most important functions is cognition, acquiring information and making sense of it, which is what is generally called thinking. Hearing is one significant way the brain gathers information to process. 

Hearing loss complicates this by sending garbled or reduced signals, forcing the brain to work harder to interpret the data. The brain is a highly functional organ but does not have unlimited capacity. If it spends more time on hearing input, it has less time for other information. According to one estimate, people with hearing loss can experience a 30 percent reduction in cognitive abilities.

Hearing and Memory

The link between hearing loss and memory loss is substantial.  As a person ages, the brain begins to shrink. While areas of the brain that are involved in hearing, such as the auditory cortex might be expected to shrink due to decreased usage, some hearing involved areas of the brain also have other functions, such as the process of memory and cognition. Researchers are concerned that brain shrinkage in these multi-use areas can affect brain processes other than just hearing.

 In a recent study of 140,000 adults aged 65 and older, 9 percent reported having hearing loss. Thirty-seven point seven percent of this group also said they had memory loss. Among those who did not have hearing loss, only 5.2 percent said they had hearing loss. 

One long-term study followed 126 participants over ten years, testing hearing and using MRIs to measure brain size. It showed that the brains of adults with hearing loss experienced accelerated shrinkage. They lost up to an additional cubic centimeter each year as compared to those who did not have hearing loss. The researchers concluded that hearing loss led to a faster rate of brain atrophy. 

Dementia

Dementia is not a specific disease.  It describes symptoms such as memory loss, impaired thought processing, and personality changes that interfere with daily life. The best known is Alzheimer’s disease, but it is one of many types of dementia. The symptoms frequently appear as a person ages. Research on adults aged 45-64 has shown that hearing loss is a top risk factor for dementia. It is estimated that hearing loss is responsible for 8 percent of dementia cases.

Treatment

Hearing loss is connected to impaired thinking, memory loss, and more complicated memory disorders that fall under the category of dementia. However, the situation for those with hearing loss is not hopeless. Studies have shown that hearing aids help.  One study showed that the loss of information in immediate and delayed recall situations was slowed down with the introduction of hearing aids. Technology can help improve hearing for those who have developed hearing loss.

It is important to treat hearing loss early before structural changes to the brain occur. If you or a loved one is experiencing hearing loss, now is the time to contact Hearing Associates of Las Vegas for an evaluation and treatment options.