Why do older people sometimes have more difficulty getting used to wearing hearing aids? The answers to all of these questions have to do with sensory deprivation.

Sensory deprivation can be defined as a lack of stimulation of the sensory organs by external agents, which can lead to numerous issues. Essentially, when a sense is not working properly, it stimulates the brain less. With hearing loss, for example, a damaged ear sends less information to the brain, depriving it of certain sounds. The brain may then become “underused,” as it is less stimulated by its environment.

Studies have shown that when people with mild hearing loss perform a visual task, the auditory centre of the brain activates (nervous activity). What’s more, when those same people are asked to perform an auditory task, the auditory centre of the brain is less active. This means that when a person has hearing loss, depriving the brain of certain sounds, the cognitive resources that would normally be used for hearing are instead used to process visual information. Over time, this gives the brain fewer and fewer resources to process auditory information. Hence it being “underused.”

This also explains why people who have lived with hearing loss for a long time have more and more trouble understanding speech. Studies have found that the brains of people with hearing loss also use auditory resources to process tactile (touch) information.

Fortunately, other studies have shown that early intervention can reverse this process. They suggest that wearing hearing aids can stimulate areas of the brain that have been “underused” because of hearing loss. This is possible thanks to brain plasticity, which is the brain’s ability to create, destroy or reorganize neural networks and the connections between neurons to adapt to an individual’s environment and experiences. In other words, hearing aids can help the brain relearn how to access the sounds around it, causing it to use more resources (neurons) to process auditory information. However, there are two factors to consider: it’s important to act quickly after hearing loss appears, and younger people generally have greater brain plasticity.
In sum, hearing loss over several years makes our brains less able to understand speech, because they are less stimulated by their environments. However, hearing aids can help reverse this process by stimulating the brain’s auditory centre again. However, the sensory deprivation must not have been happening for too long, and people lose brain plasticity with age.

For more information, talk to an audiologist.

References:
BERGERON, F. Plasticité cérébrale et surdité : État des lieux. Presented at the Journée scientifique Lobe. Québec, Canada. 2018. SHARMA, A. Marion Downs Lecture: Brain Changes in Hearing Loss. Presented at the 29th Audiology Now! conference. Indianapolis, United States. 2017.