The study, which was published in JAMA Otolaryngology—Head & Neck Surgery, linked hearing loss to the modestly increased risk of cognitive impairment and dementia and to declines in all aspects of cognition.

There are many possible explanations for the link between hearing loss and cognitive decline. For instance, the two conditions may share an underlying mechanism, such as a decline in the vascular system, or hearing loss may be a marker for general physiological decline and frailty. Hearing loss may also compromise cognitive processes because so much effort is needed to process auditory information. And it often increases social isolation, which is a risk factor for cognitive decline, presumably due to reduced stimulation.

Though none of the studies in this analysis assessed whether hearing aids help protect cognition, the researchers cited other research indicating that the aids may have such benefits in older people who are still cognitively intact, though not in those who already have dementia.

If you are concerned that you or a loved one might be suffering from hearing loss, talk to your healthcare provider. You might also want to consider taking the National Hearing Test (NHT). The NHT is considered a reliable screening test for hearing loss. It is done over the telephone and involves listening to a series of numbers spoken against a staticky background, simulating the attempt to discern speech in a noisy room. The NHT can detect the most common type of hearing loss, presbycusis, which affects the hearing part of the inner ear called the cochlea and is common among older people. The NHT costs $5 (free for AARP members), takes 10 minutes, and must be done on a landline in a quiet room. If your hearing falls below normal limits, you’re advised to consult a hearing professional. Go to NationalHearingTest.org for more information, or call 844-459-0569.