We have previously discussed the association between hearing loss and falls but it seems new data is emerging regularly on this topic, likely given the magnitude of this societal problem.
Hearing loss is prevalent, with an estimated 15% of American adults reporting some difficulty hearing. The prevalence of hearing loss also increases significantly with advanced aged. Sensorineural hearing loss is the most common hearing loss type and is often due to the death of cochlear hair cells. Sensorineural hearing loss can occur secondary to aging, noise exposure, chronic metabolic conditions such as diabetes, medications, toxins, and cardiovascular disease, to name just a few.
At present, there is no way to medically regrow these hair cells, making the hearing loss permanent. Sensorineural hearing loss is currently treated with hearing aids and/or cochlear implants.
In recent years it has also become clear that there is an association between hearing loss and falls. A recent meta-analysis showed a 51% increased risk for falling than those without hearing loss. Another, slightly older, meta-analysis showed a 69% increased odds of falling for those with hearing loss.
The likelihood of a fall, particularly an injurious fall, increases with advanced age. It is estimated that as many as 1 in 4 elderly individuals fall annually. Falls are a large societal problem for our aging populations and as such much effort is being put toward falls prevention.
After reading these statistics, I am sure the first question that many will ask is “Why is hearing loss associated with falling?”. At present there is no definitive single explanation for this association and there may be multiple processes at play, but there are several theories.
Concomitant Hearing Loss & Vestibular Dysfunction
The vestibular/balance portion of the inner ear works as a gyroscope of sorts, orienting the individual to space. Inner ear vestibular dysfunction can occur due to aging, head trauma, congenital malformation, as well as due to infectious or viral insults. Some processes that cause dysfunction to the vestibular portion of the inner ear also result in hearing loss.
It is also known that vestibular hair cell populations decline as we age, similar to the declines in hair cells observed in the cochlear portion of the ear. The full impact of age-related decline in vestibular dysfunction is still not fully understood.
However, there is clear evidence showing that vestibular dysfunction is associated with a significantly higher risk of falling.
Cognitive Load / Cognitive Decline
Cognitive load may play a role in the association between hearing loss and increased falls risk. Everyone has a certain amount of cognitive ability to process all stimuli. If someone doesn’t hear as well as they once did, then they may pull some of their cognitive abilities from being environmentally aware toward hearing, thus increasing the risk of tripping and/or falling. Hearing loss is also associated with cognitive decline and cognitive decline is also clearly associated with a higher risk for falling.
Any declines in cognitive function likely only exacerbate this cognitive load effect.
Spatial Awareness
We as humans primarily use our senses of vision, touch/proprioception, and vestibular inputs to maintain balance. An impairment to any of these sensory systems can lead to imbalance and falls. It seems that we may also utilize acoustic cues to provide additional sensory information to maintain balance. It has been shown that we utilize acoustic reverberations to give us some idea of distance to an object, creating an acoustic picture of our environment.
This process would seem like echolocation, although in a more rudimentary form. Any loss in this sensory redundancy may lead to an increased risk of falling.
Do Hearing Aids Help Prevent Falls?
There are some individual studies that suggest that hearing aids may help reduce the risk of falling, but the evidence is still mixed. One study showed that individuals with hearing loss that did not wear hearing aids were more than twice as likely to fall than their peers who wore hearing aids, suggesting a protective effect from hearing aid use.
Another study showed no correlation between hearing aid use and odds of falling. Yet another study showed a nearly 50% reduction in the odds of falling for individuals that regularly used their hearing aids. At present the data is mixed on the use of hearing aids for falls prevention. Higher levels of evidence provided through a meta-analysis are needed to clarify the benefits of amplification in preventing falls.
I look forward to additional research emerging in this area to better determine the role of amplification in falls prevention.
