A Link Between Hearing Loss & Dementia

A Link Between Hearing Loss & Dementia

One of the effects of hearing loss is that spoken communication becomes more difficult. Although you might have hearing loss only in one range of sound, the ability to hear human speech actually incorporates quite a rich combination of sounds, making it difficult for most people with hearing loss to communicate effectively. Sure, losing the ability to hear the richness of the natural, musical, and social worlds is an unfortunate effect of hearing loss, but the inability to carry on a smooth conversation can have other indirect effects. 

Researchers have noticed a connection between hearing loss and dementia, and this inability to hold fluid conversations might have something to do with the relationship. Let’s begin by looking at some of the research about a connection between hearing loss and dementia. Then, we can consider how the two might be related. Finally, we can explore the benefits of treatment for not only hearing but also cognition. 

The Connection between Hearing Loss and Dementia

Before we consider how these two conditions might be related, let’s establish the bare facts. Dr. Frank Lin at Johns Hopkins University is a leader in the field of research on this connection. If you look at comparable groups of people in terms of age, race, gender, education, income, and a whole host of other factors, the group with hearing loss will have much higher rates of dementia than the group without hearing loss. A 2011 study observed a group of 639 people who did not have any symptoms of dementia or cognitive decline at the outset of the study. 

These individuals were tracked for 12-18 years to see how their mental ability proceeded over these years. This study made it possible to compare individuals within the groups with different characteristics. Even among those who were otherwise similar, the worse their hearing at the outset of the study, the worse their cognitive ability by the end of the study, on average. This result is not to say that everyone who has hearing loss will develop dementia. However, the rates are higher for those with hearing loss than for those without. 

Understanding the Connection

Although the raw numbers establish that there is a connection between the two, it takes more scientific understanding to see how these two are related. Most researchers point to the ability to carry on verbal conversations and to understand speech. When hearing loss sets in, our ears are no longer gathering a steady stream of phonemes that assemble into recognizable words and phrases. Instead, we can only hear a jumble of sounds, much like the pieces of a puzzle. Without all the pieces of the jigsaw puzzle in hand, our brains struggle to make a picture out of the pieces we have available. This process is certainly exhausting for the brain, but it appears that the strain to make sense of sound might bleed into other areas of cognition, as well. 

Scientists have taken images of brains with and without hearing loss. When they are processing language, the brains of those with hearing loss use more of the part of the brain devoted to complex thought than those who have full hearing ability. This displacement might lead to an overload in that part of the brain, and it can also lead to dysgenesis in the parts of the brain devoted to auditory processing. 

The Value of Treatment

The good news is that exploratory research is showing that those who have hearing aids do not look any different than their counterparts without hearing loss when it comes to cognitive ability! It seems that the hearing aids are able to replace those missing sounds in speech, making it possible to eliminate the disproportionate effect that hearing loss causes when it comes to dementia. Keeping your mind sharp is an exercise routine, much like our physical bodies require. 

In order to keep a strong and healthy mind, it needs to be fed plenty of challenging information and given tasks that exert it in the right ways. Hearing loss deprives the brain of some of the sustenance and exercise it needs to thrive, but treatment in the form of hearing aids can keep the mind active and nourished!