November 18, 2020

Hearing Loss And Dementia Are Linked

Hearing Loss And Dementia Are Linked

Don't Forget Your Sense Of Hearing

Hearing is one of our most under-appreciated senses. Without sight, most of us would come to a dead stop. Our ‘hearing’ doesn’t hurt like when our sense of touch experiences a sunburn. We relish and spend huge amounts of time preparing and consuming our favorite foods - enraptured in our sense of taste and smell. Our hearing is something most of us just take for granted or it’s a terrible annoyance that keeps us from sleeping. We should not

The reality is that compromising our sense of hearing is as profound as any other. Hearing loss is a key indicator of lost income and poor work performance, particularly with men. Hearing loss can lead to social isolation, loss of self-esteem, and depression. Because hearing loss is frequently noise-induced, those that suffer from earlier onset hearing loss often work in very loud environments. Or perform in them. Musicians, performing artists, the crew and sound engineers that work with them, and, their armies of fans are at significant risk of permanent hearing loss. 

Most alarmingly, experts now say that hearing loss and dementia are linked and the risk could be higher than previously thought. Understanding dementia and the urgency to avoid it is critical. This article will explore dementia, the negative effects of hearing loss, different types of hearing loss, and review the groups most at risk. It will also discuss recent studies on the link between hearing loss and dementia, and point to solutions for tackling this sensory impairment early on for the best chance of fighting off memory-related degenerative diseases. 

What Exactly Is Dementia?

Dementia is an umbrella term for memory-related and cognitive decline diseases. It is a chronic syndrome and is a result of abnormal brain changes. These changes result in compromised thinking skills and cognitive abilities that are severe enough to impair daily life and independent function. Dementia also affects behavior, feelings and relationships. There are psychological, social, physical and economic impacts on those suffering from dementia and their caregivers.

Most people receive a diagnosis when they present a clear decline in cognitive abilities, to a degree where it affects their daily life and independence. This could look like general forgetfulness, difficulty finding objects, or inability to recognize familiar people. It’s a common myth that mental decline is a natural effect of aging. Damage to the hippocampus is part of dementia, which is why memory loss is the first sign of Alzheimer’s. These diseases are progressive, meaning the symptoms increase in intensity over time.  Studies show that the consequences of dementia are dire. 

Also, hearing loss amplifies a person’s risk for dementia.

Negative Effects of Hearing Loss

Hearing loss does not discriminate. However, research points to men as the group at the highest risk for noise-induced-hearing-loss with the most dramatic hearing loss-related consequences. Some hearing loss is to be expected along with the natural aging process but for many people it’s noise-induced. Adults with untreated hearing loss are far more likely to experience loneliness, anxiety, depression, and paranoia. Plus, they aren’t as likely to join activities like community organizations or casual social engagements.

When untreated, hearing loss immensely increases a person’s cognitive load. People with hearing loss have to do so much more work to focus their attention, figure out who is speaking, as well as filter out other noises and interpret what is being said. These difficulties make it much more difficult to have conversations, understand instructions, or simply respond to requests and can radically impact socialization. Misunderstanding someone can be challenging at the best of times and isolating at the worst of times. 

Hearing loss also makes it very difficult for someone to advance in their career. Studies show a clear link between hearing loss and either unemployment or loss of income. Research shows that the slow downhill slide can begin with simple discomfort in the workplace. At the height of a career in late middle age, most people’s earning potential will probably hit an all-time high at the same moment that hearing loss begins to occur. 

There are tools we can use to cope with hearing loss should it occur. Hearing aids are widely available but many people, particularly men, refuse to wear them. According to the International Journal of Audiology, about 25 percent of people who own hearing aids do not wear them, “men more than women.” New sophisticated tools to strengthen hearing ability are also now available. These resources keep the brain as active as possible and take a measure of the auditory ability of each ear over time.

Types and Causes of Hearing Loss 

From inconvenient to profound, doctors use several classes to categorize the experiences of individuals suffering from hearing loss. It’s important to clarify that deaf individuals and people who have been hard of hearing since birth experience different challenges than people who experience hearing loss later in life. This section focuses on people who are losing their hearing as adults. 

Sensorineural Hearing Loss

The most common type of hearing loss is sensorineural, or nerve-related hearing loss. This is primarily caused by exposure to loud noises, but can also be a result of simple aging, and it causes irreparable damage to the nerves of the inner ear. Live events are a classic culprit when it comes to noise-induced hearing loss. From concerts to sporting events, the decibel level in some of these venues can be ear-shattering. Without proper ear protection, even a single concert can have devastating effects on long-term hearing.  

As discussed, one of the most at-risk groups for sensorineural hearing loss are musicians. For people who use amplification regularly, either in rehearsals or performances, consistent ear protection is critical. The British Medical Journal found that professional musicians are four times as likely to experience noise-induced hearing loss as the average person. Not only that, but musicians are 57% more likely to develop tinnitus.

Conductive and Mixed Hearing Loss

A less common type of hearing loss is called conductive hearing loss. This is when a blockage prevents sound from reaching the inner ear, and it can often be fixed with surgery. It frequently occurs in people who have an oddly shaped ear canal from birth or who have an earwax buildup or other blockage. 

Mixed hearing loss occurs when a combination of both types are present, including conductive and sensorineural hearing loss. In this case, a combination of ear protection and hearing aids might be appropriate.

Experts consider even a small amount of hearing loss to be significant if someone is struggling to hear or understand someone who is speaking normally. With very severe hearing loss, a person may only be able to hear very loud sounds and potentially no speech at all. Doctors evaluate a person’s hearing loss across several axes, including how much they can hear as well as how much their hearing loss is affecting daily life.

The Link Between Hearing Loss and Dementia

Scientists are breaking new ground at the intersection of sound and degenerative brain diseases at Newcastle University in the UK. Researchers are focusing on three core ideas. The first is that there could be a common underlying cause for both hearing loss and dementia. The second is that a lack of sound-related input may lead to brain shrinking. This would corroborate other studies that show shrinkage in the brain parts related to sound processing and speech, like the inferior, middle, and superior temporal gyri. Third, they are studying whether hearing loss might force a person to utilize more brain resources to compensate for their inability to hear. This makes the brain unavailable for other mental tasks and leads to cognitive impairment.

In a study published in the journal Neuron, they point to startling new conclusions about the connection between the memory center of the brain and its auditory processing hub. For instance, the temporal lobe has been frequently associated with long-term memory about events and familiar places. 

Newcastle researchers say the temporal lobe is also involved in the manipulation of auditory information and the storage of short-term memory. The lab is also examining the possibility that hearing loss could directly encourage the production of abnormal proteins that cause Alzheimer’s.

This research indicates that, by simply focusing on avoiding preventable hearing loss, people can reduce their future risk for dementia. Anyone can help fend off neurological disorders like Alzheimer’s by wearing comfortable ear plugs that protect the nerves of their ears from damage. Since hearing loss has a demonstrated negative effect on income and family relationships as well as memory-related illnesses, everyone should wear noise-canceling ear plugs to keep their hearing healthy and protect themselves on all three fronts. Hearing aids can also help in the fight against Alzheimer’s. As one article put it, “Alzheimer drugs are great, but taking control of your brain is better.” 

Relationship Between Cognitive Function and Hearing Loss

In prior animal studies, structural changes were observed in the brain when the animals experienced enriched (versus impoverished) auditory environments. With greater cognitive and auditory stimulation, their brain tissue thickened and increased complexity was observed at the level of dendrites, synapses, and vasculature. To extrapolate, some experts believe that this level of brain development, also known as cognitive reserve, can protect against dementia in humans. 

In other words, auditory stimulation leads to brain development and increased cognitive function. When hearing loss prevents auditory stimulation, brain degeneration follows. In the studies described above in Neuron, participants suffered from memory-related illnesses. They were evaluated five years after their initial study and other risk factors were taken into account. The behavioral data observed in this study corroborates what other researchers predict about the relationship between cognitive function and hearing loss.

Hearing Protection to Combat Dementia

Maintaining hearing health is about far more than just keeping the ability to understand auditory information. Hearing loss can lead to and worsen memory-related diseases like Alzheimer’s. Preventable hearing loss contributes to early-onset dementia, and it’s one of the best ways for average people to take action to protect themselves today. The first step is to implement a hearing protection program in environments where loud noises could damage the auditory system. From the stage to the stadium, preventative measures are crucial in protecting ears over decades. 

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