Unveiling the Relationship between Communication, Hearing Loss, and Dementia
The correlation between communication and cognition continues to grow stronger as new evidence emerges. The close connection between hearing loss and dementia is increasingly recognized. Given that millions of adults currently experience hearing loss, and an estimated 150 million people worldwide may face dementia by 2050, understanding the relationship between these conditions is crucial and time-sensitive in order to minimize associated risks.
Research has revealed that hearing loss is a potentially preventable factor contributing to dementia. Studies, such as one conducted by Johns Hopkins, followed over 600 adults for 12 years and discovered that even mild hearing loss doubled the risk of dementia. The risk further escalated with moderate hearing loss, tripling the likelihood of dementia, while severe hearing loss increased the risk by fivefold.
Dementia is an overarching term encompassing difficulties in thinking, communication, and memory, which impact mood, personality, and behavior. While various causes contribute to dementia, Alzheimer’s disease is the most common. The risk of both dementia and hearing loss increases with age.
Given that approximately one-third of older adults experience hearing loss, the recent availability of over-the-counter (OTC) hearing aids has been welcomed by medical professionals and public health experts. OTC hearing aids are not only typically more affordable, but they also reduce the need for multiple appointments and enhance accessibility. This increased accessibility facilitates the maintenance of oral language, which serves as a vital connection between communication and cognition—the capacity to think.
“Language and cognition are distinct processes; however, they are highly interdependent,” explained Brooke Hatfield, Associate Director of Health Care Services in Speech-Language Pathology at the American Speech-Language-Hearing Association. In an email, she highlighted, “Language serves as an internal framework for reasoning, problem-solving, memory, and other cognitive abilities.”
Exploring the Interplay Between Hearing Loss and Dementia
The Cochlear Center for Hearing and Public Health, an entity affiliated with the Johns Hopkins Bloomberg School of Public Health, has identified hearing loss as the leading contributor to “potentially preventable” cases of dementia. This prevalence surpasses other factors that may influence the risk of dementia, including high blood pressure and lower education levels, with the latter potentially stemming from socioeconomic challenges and various other elements.
Researchers propose that hearing loss affects dementia risk by impeding the entry of sound into the brain. When individuals struggle to hear, their brain exerts additional effort to comprehend sounds, potentially accelerating the aging process within the brain. This, in turn, restricts cognitive abilities and memory recall, as described in a fact sheet provided by the Cochlear Center.
Furthermore, the loss of auditory abilities restricts communication and connection with others, thereby increasing the likelihood of social isolation—an existing public health concern among seniors and older adults. The US Centers for Disease Control and Prevention have found that social isolation is associated with an approximate 50% higher risk of dementia and other health issues.
The various theories regarding the relationship between hearing loss and dementia also raise the possibility of a “chicken or the egg” scenario, as noted by Hatfield. Research suggests that hearing loss can serve as an indicator of ongoing brain changes rather than being the primary cause of such changes.
It is worth mentioning that not all individuals with hearing loss develop it gradually, and the risk of dementia does not appear to be the same for those with lifelong deafness. According to the UK-based charity Social Care Institute for Excellence, individuals who were born deaf and communicate using sign language do not exhibit an increased risk of dementia compared to the general population.
However, Hatfield acknowledges concerns surrounding the diagnosis of dementia in deaf patients due to limitations in testing methods and a lack of experience among healthcare providers in working with the deaf community. Nonetheless, maintaining engagement in communication and avoiding social isolation may serve as a potentially protective factor against dementia risk.
“The association between hearing loss and dementia seems to be linked to the history of changing hearing and subsequent brain changes, rather than the act of hearing itself,” Hatfield added.
The Potential Protective Role of Hearing Aids Against Dementia
Recent research suggests that hearing aids can play a significant role in safeguarding against dementia. A study published in The Lancet last month revealed that individuals with hearing loss who utilize hearing aids do not face an elevated risk of dementia compared to those without hearing loss. The study utilized data from the UK Biobank, examining the health records and dementia diagnoses of a large cohort of adults aged 40 to 69 from England, Scotland, and Wales.
Although further research is required to establish causality, the study authors stated that hearing aids could potentially serve as a minimally invasive and cost-effective intervention to mitigate, or at least partially counteract, the impact of hearing loss on dementia.
In line with these findings, a comprehensive systematic review conducted in February provided additional evidence supporting the notion that hearing aids, when used by individuals in need, may help reduce the risk of cognitive decline. The review analyzed studies on the use of hearing aids and their association with the risk of cognitive decline, revealing a 19% decrease in long-term cognitive decline among individuals who used “hearing restorative devices.”
The speed at which hearing aids can provide benefits varies depending on individual circumstances. On average, people wait seven to nine years to seek hearing loss treatment, which often involves obtaining hearing aids. However, similar to other medical conditions, seeking treatment for hearing loss at an earlier stage yields better outcomes, as emphasized by Bria Collins, Associate Director of Audiology Practices at ASHA.
Collins explains that, akin to exercising a muscle, hearing, and language need regular practice. Delaying treatment for spoken language users with hearing loss can make it more challenging to readjust to hearing speech and environmental sounds. For example, if a runner took a prolonged break from exercising, their athletic performance would not be on par with their previous level of fitness when their muscles and endurance were accustomed to regular exercise.
The time required for someone to regain their language skills or performance after getting a hearing aid can vary. Some evidence suggests that the brain adapts to the presence of a hearing aid after approximately four weeks. While individuals often experience immediate relief from “listening fatigue” in situations like watching TV or engaging in one-on-one conversations, adjusting to more demanding listening environments that necessitate greater discernment, such as restaurants, bars, or bustling family gatherings, may require more time.
The adjustment period also depends on the duration of hearing loss and its severity. Transitioning from struggling to hear to being exposed to a world full of sound can be overwhelming for some patients. Audiologists may therefore gradually fine-tune hearing aids over time to prevent patients from feeling overwhelmed. This gradual adjustment is one aspect where over-the-counter hearing aids may fall short compared to prescription hearing aids that are fitted by professionals.
Collins clarifies that there is no specific timeframe for the brain to adapt to amplification since individual variability plays a significant role.
It is important to note that the information presented in this article is intended solely for educational and informational purposes. It should not be interpreted as health or medical advice. For any inquiries regarding medical conditions or health objectives, it is always advisable to consult with a physician or other qualified healthcare provider.