How Loud is Too Loud? Part Three: The Long-Term Effects of Hearing Loss

Key Points

• Long term effects of hearing loss can include cognitive decline, increased risk of falls, depression/anxiety, and social isolation.
• Hearing loss, which is also common in older adults has been found to be associated with clinically significant cognitive decline as well as MCI.
• Those aged 50 and older with untreated hearing loss were found to be more likely to report anxiety, depression, and feelings of paranoia.

The Long-Term Effects of Hearing Loss

Of those aged 65 to 74, 25% experience significant hearing loss. This percentage increases to 50% in those over 75 (NIDCD). Any untreated hearing loss, whether it be due to aging or noise exposure has effects beyond simple hearing difficulty. Hearing loss has been significantly associated with poorer quality of life, social isolation, depression, and cognitive decline. While these outcomes do not necessarily effect everyone, and there are many other things involved in their development, those with hearing loss are more at risk.

Cognitive Decline

In adults aged 60 and older, 5 – 7% present with dementia. It is anticipated that globally this number will double every 20 years until 2050 (Dawes et al., 2015). Perhaps even more concerning, is the number of older individuals with mild cognitive impairment (MCI). MCI describes individuals whose cognitive function falls between that of normal aging processes and severe cognitive impairment, dementia, or Alzheimer’s disease. In other words, memory loss is experienced to a greater degree than others in the same age range, but it does not fall within the clinical criteria for cognitive impairment. This is not only important for these individual’s quality of life, but often those with MCI will progress to dementia/Alzheimer’s disease more quickly than a healthy individual of the same age would (Peterson et al., 2001).

MCI and other forms of cognitive decline do not have an impact on the affected individual alone, but also their caregiver, family, and the healthcare system as a whole. These affects include emotion as well as financial (Dawes et al., 2015).

Hearing loss, which is also common in older adults has been found to be associated with clinically significant cognitive decline as well as MCI. While the exact relationship is unclear, there are two main hypotheses: common cause, and cascade.

The common cause hypothesis suggests that age-related changes in the nervous system cause both hearing loss and cognitive decline. Meaning that these two disorders share neurodegenerative mechanisms (Dawes et al., 2015).

The cascade hypothesis suggests that the deprivation that hearing loss causes within the auditory system impacts cognition either directly, or through the effects of depression and social isolation (Dawes et al., 2015). In other words, either reduced auditory input impacts cognition or reduced auditory input causes depression and social isolation which impacts cognition.

As mentioned in part two, increased the cognitive effect given to hearing and understanding may use up cognitive resources resulting in the appearance of cognitive decline. While this hypothesis is an unlikely cause, it is certainly a contributing factor in the association between hearing loss and cognitive decline (Dawes et al., 2015).

Depression/Social Isolation

Those aged 50 and older with untreated hearing loss were found to be more likely to report anxiety, depression, and feelings of paranoia. The reports of depression, specifically, were noted to occur two or more weeks in a year. Additionally, these individuals were less likely to participate in social activities which can lead to feelings of social isolation (American Academy of Audiology).

Social isolation has been found to be significantly associated with both poorer hearing and poorer cognition. Social isolation and poorer hearing are both significantly associated with higher frequency of depression. Frequency of depression and social isolation are significantly associated with poorer cognition (Dawes et al., 2015). In other words, these four factors work in a cycle with one another. For example, a person with hearing loss may begin to feel social isolated by their inability to communicate properly which can result in depression. Overtime, this isolation and depression may lead to cognitive decline.

Falls

Untreated hearing loss has also been associated with an increased risk of falls.

In person’s over 65, trauma is the 5th leading cause of death. In those 75 and older, falls account for 70% of accidental deaths. Hospital stays are longer for elderly patients after a fall than those admitted for other reasons. Additionally, those who do fall experience a greater decline in activities of daily living than those who do not have a history of falls (American Family Physician).

A significant link has been found between untreated hearing loss and falls risk with hearing impaired individuals being 3x more likely to experience a fall than those without hearing loss. This association may be a result of limited access to environmental cues needed for awareness. It may also involve cognitive load and attention. When individuals’ cognitive resources are hyper-focused on trying to hear sounds around them, resources are taken away from things like attention and postural control which can increase the risk of tripping or falling.