Alison Love - The Effects of Hearing Loss on the Body

Okay.  Welcome, everyone.  Thank you for coming today.  So I am one of the audiologists that works at the Broadmead location and my presentation today is titled "The Effects of Hearing Loss on the Body" and I'll be talking quite a bit about this topic, but also about the effects of other health conditions on hearing.  So it's sort of both sides of the coin that you'll be getting today.  Can everyone at the back hear me well?  Okay, perfect.  Good.

So there will be some times for questions at the end of the presentation, so please hold on to your questions until then. 

A brief introduction to who I am:  I did my undergraduate degree at the University of Victoria in linguistics and then I went to the University of British Columbia to pursue my master's degree in audiology.  I graduated from there in 2008.  I worked at Broadmead Hearing Clinic shortly after I graduated and then I spent a few years on the mainland before making a permanent move back to Victoria and starting to work again at Broadmead Hearing Clinic in January of 2017, so just over a year ago. 

I've had the opportunity to work in a few different centres, including public health audiology clinics, hospitals and private hearing‑aid clinics, so I've seen pretty well the full spectrum of audiology and a really diverse population of patients.

So an outline of what I'll be talking about today:  I'll first provide some statistics and definitions and then I'll talk about chronic diseases and the link to hearing loss, the psychosocial effects of hearing loss, hearing loss and falls and I'll conclude with some myths about untreated hearing loss. 

I'd like to make a note that I haven't referenced my research materials in this presentation, but I'm more than happy to provide them to anyone who is interested.  So please either approach me after the talk or take down my e‑mail address, which I will put up at the end of the presentation. 

Okay.  So here we go.  Hearing loss is a highly prevalent, chronic condition, particularly in the senior adult population.  Recorded by Stats Canada using hearing data from 2012 to 2015, there are about 4 million people in Canada who are living with hearing loss.  About 40 per cent of adults aged 20 to 79 had at least a slight hearing loss in one or both ears, and hearing loss was most prevalent in older age groups, affecting 78 per cent of adults aged 60 to 79.

About 77 per cent of adults with at least a slight hearing loss did not report a diagnosis of hearing problems by a healthcare professional and a statistic that's tossed around a lot in audiology is that most people wait an average of seven years before acknowledging hearing loss and seeking help.

So the question is why wait seven years?  For some people, it's because of denial that they have a hearing loss, which I think is often related to the stigma around hearing loss, that it's a sign of old age.  People with hearing loss often develop work‑arounds.  They may find that it's relatively easy to compensate for hearing loss by turning up the volume of the television or by asking people to repeat themselves in conversation. 

Most hearing loss has a gradually progressive nature, so you don't wake up one day and realize that you're not hearing the crickets in the back yard or the blinker in your car, and most hearing loss has a high frequency nature, so you ‑‑ so you aren't missing all sounds and it doesn't sound like people are speaking quietly, but it more likely sounds like they're mumbling or they're not articulating clearly.  So the volume might be appropriate for voices, but the clarity is lacking. 

Hearing loss is often referred to as an invisible disability.  It can't be visually observed like a limp, for example, and it's subjective, so people cope differently with the same degree of hearing loss. 

So I'd like to set out some definitions of terms that will come up again and again throughout the presentation:

Comorbidity is the coexistence of two or more chronic conditions in an individual and a chronic condition is a disease that lasts for more than three months. 

Correlation is a connection between two or more things, while causation is the action of one thing causing another thing.  It's quite important to remember that association or correlation does not imply causation, meaning that just because hearing loss and dementia are associated, it doesn't mean that hearing loss causes dementia.  So I'll be talking about a few different conditions that are correlated with hearing loss, but that aren't necessarily caused by hearing loss.

So here's a question that comes up:  Is hearing loss a chronic condition?  And as I mentioned before, it is, and in fact it's one of the most prevalent chronic conditions in older adults. 

And for someone who might be skeptical about this, we compare hearing loss to diabetes, which is undeniably a chronic condition.  Like diabetes, hearing loss is invisible, it's progressive, painless, it's long‑lasting and it's frequently treatable, but it's not curable.  Also when an individual accepts responsibility for managing their diabetes or their hearing loss, there's typically a positive outcome. 

Okay.  So I'll take a very quick moment to take you back to Grade 6 science and talk about the hearing system and how exactly we hear.  I'm just going to try to use a pointer as I walk through this.  Okay.

So when we hear a sound, a sound wave travels through the ear canal and it hits the eardrum and it begins to move the three small bones in the middle ear.  These are the smallest bones in the body, by the way.  And then the sound reaches the inner ear, the snail‑shaped structure, which is also called the cochlea.

Inside of the cochlea, we have thousands of tiny hair cells and these hair cells convert the mechanical signal into an electrical signal, which is then sent along the hearing nerve up to the brain. 

Once the signal reaches the brain, we are able to make sense of the sound by drawing information from other parts of the brain to help interpret and understand what we've heard.  So hearing not only relies on the ear and its components, but also a functioning hearing nerve and the auditory cortex, which is the part of the brain that receives the signal. 

So back to the idea of comorbidity:  There are some diseases and disorders that are more likely than others to be comorbid with hearing loss and it's very important for audiologists and patients to know about these relationships, so I'll spend a bit of time talking about each. 

It's really been within the last decade that a lot of these studies have come up linking hearing loss to other chronic diseases and it's likely for a few different reasons:  Our society has had an increased focus on wellness, our population is aging, there is an increasing appreciation for the importance of healthy hearing and there has been increased sophistication in epidemiological data analysis, so the study of health and disease, determinants and distribution.

Some of the chronic conditions that I'll talk about, but certainly not all of them, are diabetes, thyroid disease, chronic kidney disease, cardiovascular disease and dementia. 

One study from 2013 showed a prevalence of hearing loss among those with diabetes that was more than twice that of those without diabetes.  The reason for this is likely that high blood glucose levels damage the blood vessels inside the cochlea, the inner ear, which disrupts sound reception. 

Also there are likely mechanisms related to neuropathic or microvascular, so the small blood vessels, and inflammation that can cause an association between diabetes and hearing loss.  Roughly 30 per cent of adults with diabetes will experience hearing loss and roughly 39 per cent will experience balance disorders.

Hypothyroidism is a persistent low level of circulating thyroid hormone and thyroid hormones ... which is the way the body uses energy.  This can effect a lot of organs in the ... without enough thyroid hormone, some of the body's functions slow down.  This can result in different types of hearing loss and some studies have suggested that the degree of hearing loss increases with the severity of hypothyroidism. 

Tinnitus is a term that you might have heard.  Some people say tin‑eye‑tis (phon.).  It's the sensation of perceiving sounds that are not present in the external environment.  It's also described as a ringing or buzzing or humming sound.  Tinnitus is a very common side effect of thyroid dysfunction and it also reduces or resolves once the underlying thyroid issue is addressed. 

So chronic kidney disease:  There is a higher prevalence of hearing loss among older adults with chronic kidney disease compared to those without.  One large study of 2900 individuals over the age of 50 indicated that 54 per cent of patients with chronic kidney disease had hearing loss compared to 28 per cent of those without kidney disease. 

Kidney disease and hearing loss share common risk factors including diabetes, high blood pressure and older age.  The tissues of the kidney and the inner ear have structural and functional similarities and also toxins that accumulate in the kidney can damage nerves, including those in the inner ear.  And it's noteworthy that diabetes is the cause of about 44 per cent of cases of chronic renal or kidney disease.

Cardiovascular disease generally refers to conditions that involve narrowed or blocked blood vessels that can lead to a heart attack, chest pain, or stroke.  There is a link between cardiovascular disease and hearing loss and it's thought that inadequate blood supply and trauma to the blood vessels in the inner ear are what contributes to this link. 

This goes back to my explanation about the hearing system a few minutes ago and if you remember, we have those thousands of tiny hair cells in the cochlea, and they depend on good circulation to receive oxygen and if they don't get this, they become damaged.  It's a permanent and irreversible hearing loss when they've been damaged and it's what we call a sensorineural hearing loss.

Hearing loss appears in nearly 80 per cent of individuals who suffer from cardiovascular disease.  Part of this might be the common link of age, because typically older adults will be predisposed to cardiovascular disease and also to hearing loss.

There's a negative influence of impaired cardiovascular health on both the peripheral, so the inner ear, and also the central, so the brain, auditory systems, and for example, with respect to the brain, a stroke can result in decreased speech understanding, and this will tie in to the next few slides that I'll be talking about regarding dementia.

So the relationship between hearing loss and dementia has been receiving a lot of attention in recent years.  Dementia can be defined as a set of symptoms that may include memory problems, language problems, personality changes and difficulties with thinking and problem solving, enough to reduce a person's ability to perform everyday activities.  It's progressive and it's degenerative, meaning that symptoms gradually get worse as more brain cells become damaged and eventually die, which translates to more difficulty with memory, understanding and communication over time. 

There are over 100 identified types of dementia, with Alzheimer's disease being the most common one, and there are various causes, such as damage to the brain due to disease, which is the case with Alzheimer's and Parkinson's.  Also a series of strokes could be the cause, which is the case with vascular dementia. 

So there is a high comparability between hearing loss and dementia.  Several studies have shown that poor hearing is associated with poor cognitive function and that hearing impairment is associated with an increased risk of dementia, but all of these studies are correlational, meaning that it's impossible to tell the direction of causation.  The likely scenario is that hearing loss impacts cognition, cognition impacts hearing and that there are shared factors that impact both hearing and cognition.

Okay.  So how is it that hearing impairment can impact cognition?  There are a few possibilities.  The direct impact would be that of cognitive load.  So the idea is that we have a limited amount of cognitive resources that are available at any time.  Hearing impairment increases the amount of effort that we put into listening, so fewer resources are available for other things like processing and memory of what we've heard.  In simpler terms, hearing loss overloads the brain, which leaves deplete the resources for other cognitive tasks. 

The indirect impacts of hearing loss on cognition could be related to the lack of social stimulation that can result from hearing loss.  Hearing loss, in some individuals, results in withdrawal from social activities and isolation from others.  Social isolation has been associated with an increased risk of dementia, and also loneliness or perceived isolation is an even stronger predictor of cognitive decline than objective social isolation.

So the second scenario is where cognition affects hearing.  Listening is cognitively taxing.  You have to use attention to focus on the signal of interest, for example in a voice in a very noisy room, and you must be continually updating and making links to memory while you're listening.  So reduced cognitive ability would presumably result in poor listening ability. 

And the third scenario is where there are shared factors, where things that would cause both hearing loss and cognitive decline.  Examples would be age‑associated chronic inflammation, cardiovascular changes, genetic susceptibility and lifestyle risks, for example smoking. 

It can get overwhelming thinking about the associations between dementia and hearing loss and what we can do to stall these things, but the key take‑away, I think, is that there is valuable impact in treating hearing loss that can help in preventing the onset of dementia and also help in dementia management and also help in improving the quality of life for individuals who already have dementia and hearing loss. 

Hearing impairment creates a functional impairment in the ability to cope in daily life.  If we can remediate the additional disability that's caused by hearing loss, we can improve a person's functional ability and possibly delay or prevent the progression to dementia.  An individual may have cognitive impairment, but with adequate hearing, they can compensate well and they maybe won't get a diagnosis of dementia.

Hearing‑aids are effective in reducing disability.  They can reduce the apparent severity of dementia in people who have been diagnosed and they can enable someone with dementia and hearing loss to hear better, which may help to reduce the burden on family and friends. 

So shifting gears, the psychosocial consequences of hearing loss:  Hearing loss disrupts interpersonal communication and it interferes with perception of meaningful environmental sounds, which can result in significant distress for some people.  Some people experience self‑criticism or embarrassment when they make errors in what they've heard or when they have difficulty hearing someone.  Other people experience anger and frustration when their communication is strained. 

Psychosocial refers to the combined influence of psychological factors and the surrounding social environment.  Some of the psychological consequences of hearing loss include social withdrawal and isolation, depression and loneliness, reduced quality of life and the effects on partners and family. 

So the basic idea is that hearing loss results in compromised speech understanding and therefore more difficulty with communicating.  This in turn leads to greater effort that is put into communicating and possibly embarrassing situations. 

This can ultimately result in an individual withdrawing from social activities that characterize a healthy communicative lifestyle.  The National Council on the Aging, which is an American organization, they conducted a survey of 2300 adults over the age of 50 and they found that those with untreated hearing loss were more likely to report depression, anxiety and paranoia, and they were less likely to participate in organized social activities compared to those who wore hearing‑aids.

People who are socially isolated have little day‑to‑day contact with others, few fulfilling relationships and they lack a sense of belonging.  Social isolation increases the risk of poor eating, smoking, alcohol use, lack of exercise, depression, dementia, poor sleep and heart disease.

There have been several studies linking hearing loss and depression and there does appear to be a direct relationship between the severity of hearing loss and a degree of depression, meaning that the more severe the hearing loss, the more severe depression is reported. 

Hearing loss is an independent risk factor associated with depression, so there's a relationship between the two regardless of an individual's age, gender, or other comorbidities.

And the good news is that several studies have demonstrated that there is a positive effect of hearing‑aid use on depression.  One large study of 4,000 individuals showed that hearing‑aid use was associated with a 36 per cent reduction in depression assessed through self‑report survey measures.  A recent study indicated that both depression in patients and caregiver burden were reduced during a six‑month period of hearing‑aid use and another study documented a significant decrease in the perception of loneliness following four to six weeks of hearing‑aid use.

There is a significant association between severity of hearing loss and reduced quality of life, both in terms of physical and mental functioning.  Individuals with untreated hearing impairment can have more difficulty with functional activities, difficulty in the workplace and an ongoing sense of stress in trying to compensate on a daily basis.

Moreover, sensory loss, whether it's visual or hearing‑related, is a shared experience and it has the potential to disrupt a couple's communication and social life.

Spouses of people with hearing loss experience ‑‑ may experience increased levels of psychological distress and lower levels of social activity and there's a general idea of this term, "emotional contagion", which isn't specific to hearing loss, but it would suggest that a hearing‑impaired person's emotions may affect their spouse's emotions.  So if the partner with hearing loss has depression and loneliness related to their hearing difficulties, it makes sense that their partner may adopt some of these feelings as well. 

The use of hearing‑aids improves health‑related quality of life by reducing the psychological, social and emotional effects of hearing loss. 

So here's a statistic:  If you're over 65 years of age, you have a one‑in‑five chance of falling down this year.  The risk of falling in the elderly presents a significant healthcare and health economic concern.  Falls are the leading ‑‑ or a leading cause of fatal and non‑fatal injuries among the elderly and falls are associated with significant health, social, economic and emotional consequences.

Why is this important for hearing loss?  The hearing and balance systems are closely linked and are both affected by age‑related changes in the body.  Individuals with hearing impairment may have less environmental awareness to people, pets and other things happening around them. 

So back to this idea of cognitive overload:  When someone is using more mental resources to hear and interpret speech and sounds around them, there is less available to maintain balance. 

Hearing‑aids can help with reducing the potential for falls as they help with staying alert and balanced and they provide more of a sense of what's happening around you and what obstacles may present a risk to falling. 

A 2014 study measured postural stability, both pre‑ and post‑hearing‑aid use, and it found that participants could maintain postural stability for a longer period of time following 30 days of hearing‑aid use, and the proposed explanation for this is that the brain may use sound cues to help maintain spatial orientation, just like visible objects can serve as cues for visualizing what's around you. 

Despite having lots of information about the benefits of treating hearing loss, people still find reasons to avoid getting hearing‑aids.  Here are some of the most common reasons that we'll hear in the clinic: 

So, "My hearing isn't that bad."  Again, hearing‑aid wearers wait on average seven years before getting help.  During that time, communication with family and friends becomes more difficult and social isolation and health risks increase. 

Another one:  "Wearing hearing‑aids means I am old."  Many people with hearing loss sit silently rather than joining in to activities and conversation.  Being able to connect with other people through better hearing helps the brain stay younger and it helps you keep involved in life. 

A very common one:  "I don't like the way they look."  Hearing‑aids have come a long way in the last 15 years.  I think a lot of people have a perception of hearing‑aids that maybe their parents or grandparents would have worn.  Today they're much more discreet and they no longer whistle the way they did 20 years ago (laughter).  There are even celebrities who wear their hearing‑aids proudly such as Bill Clinton and Whoopi Goldberg, to name just a couple.

Another common one we hear:  "I think hearing‑aids are difficult to use."  Current hearing‑aids are very adaptive and very automatic.  So there is an adjustment period as the brain and the central auditory system are adjusting to sound, but for most people, it is surprisingly uncomplicated and it's an easy adjustment.  It's important to know also that there's always a trial period with hearing‑aids, so you can assess the benefit that you're getting while you're adjusting to them.

And a valid reason is that, "Hearing‑aids cost a lot," and this is true, but there are third‑party organizations that offer support to people who qualify and there's quite a range in the price of hearing‑aids, so it's worth exploring all of the possibilities if you sense that you might need them.  The non‑financial cost of hearing loss is high, so it's money that's well spent when you take into account the benefits that you will get. 

So a summary to conclude what I've been speaking about today:  There are several chronic comorbidities associated with hearing loss such as cardiovascular disease and diabetes.  There are psychological consequences to hearing loss such as depression and dementia.  There are social consequences to hearing loss such as isolation and the effect on a partner, and there are physical consequences to hearing loss such as falls.

Hearing‑aids have dramatically improved over the last several years and they can have a positive effect on a lot of these conditions that I've discussed today. 

So this concludes the presentation.  Thank you again for attending and I hope that you'll leave here with some useful information.  And I think I do have a couple minutes for a few questions, but I'll also mention that myself and my three audiologist colleagues that you see in the photo here will be outside after the session, so we're all happy to answer any questions that you have one‑on‑one as well.  Yes.

FROM THE AUDIENCE:  Your psychosocial slide had a graphic in which insomnia was prominently displayed.  Is that in association with depression or is there an independent effect on insomnia? 

ALISON LOVE:  Definitely with depression ‑‑ are you asking about the link between hearing loss and insomnia?

FROM THE AUDIENCE:  Yes.  I know there's a link between depression and insomnia.  Is there an additional link?

ALISON LOVE:  Not that I'm aware of with hearing loss, but it would be an indirect link with depression and hearing loss and other factors associated with depression.

FROM THE AUDIENCE:  The reason it takes seven years to get hearing‑aids, which I wear, is very simple:  In early hearing loss, I had no awareness of my hearing loss because when my wife would ask me something, I filled in all the gaps, unknown to me.


FROM THE AUDIENCE:  The brain filled in all the gaps until we discovered some fantastical misinterpretations of what was said!  (Laughter) I thought she wanted to be shopping and she was offering to help in the garden.  (Laughter).  So this postpones hearing loss.

ALISON LOVE:  That's right.

FROM THE AUDIENCE:  It wasn't until we actually set up some experiments by going to places like your place and having the experience of, "Oh, my God!  That's what I heard," that the realization came here.


FROM THE AUDIENCE:  So I think that's a big gap in your seven years.

ALISON LOVE:  That's right.  Thank you for your comment.  Yeah.  And like you were saying ‑‑

FROM THE AUDIENCE:  Can you please repeat?

ALISON LOVE:  I'm sorry.  So this gentleman was saying that the reason for him it took seven years to get to the point where he was ready to try hearing‑aids is because he wasn't aware that he was filling in the blanks and it wasn't until there started to become some miscommunication and some funny misunderstandings that he realized that he was actually missing things.

And it's a great point, because people with hearing loss do fill in the blanks and this takes a lot of energy, and one of the things that I hear quite often with patients that I fit with hearing‑aids after they've been wearing them for a while is that they feel like they have more energy at the end of the day because they're not working so hard to fill in the blanks, even if they're not aware that they're doing that.  Thank you for that comment.

I think probably time for one more question, but anyone else who has a question, we will again be outside afterwards.  Yeah.

FROM THE AUDIENCE:  Is there a link between vitamins and dementia? 

ALISON LOVE:  Oh, I can't ‑‑ so the question was whether there's a link between vitamins and dementia.  I ‑‑ I can't ‑‑ I'm not a dementia expert and I don't know.  I think in my slide I did mention that there are some types of dementia that could be related to vitamin deficiencies, but I can't speak much more to that, unfortunately.  Thank you.

All right, well, thank you everyone. (Applause)