In the journals
Older adults who develop hearing loss are more likely to experience greater cognitive decline and develop dementia than their counterparts without hearing problems, according to a meta-analysis published online Dec. 7, 2017, by JAMA Otolaryngology — Head and Neck Surgery. Researchers examined data from 36 studies including more than 20,000 people who underwent both cognitive evaluations and hearing tests. Those with age-related hearing loss were more likely to have cognitive impairment or a diagnosis of dementia.
The study found a small but statistically meaningful association between hearing loss and a variety of specific cognitive abilities, including executive function, memory, processing speed, and visuospatial ability (how you recognize shapes and sizes and estimate the distance between two objects). The association between hearing loss and weaker cognitive skills was still strong even after accounting for risk factors like high blood pressure and smoking.
It is not yet known how hearing loss may be related to cognitive decline and dementia. The researchers speculated that these abilities may share a common neural pathway. For instance, hearing loss may require increased mental energy to perceive speech, which leaves fewer mental resources available for other cognitive processes like memory. There also may be an indirect link. For example, hearing loss can lead to greater social isolation, which can increase the risk of cognitive problems.