Editing Hearing loss (section)

==== Cognitive decline ====
Hearing loss is an increasing concern especially in aging populations. The prevalence of hearing loss increases about two-fold for each decade increase in age after age 40.<ref>{{cite journal | vauthors = Lin FR, Niparko JK, Ferrucci L | title = Hearing loss prevalence in the United States | journal = Archives of Internal Medicine | volume = 171 | issue = 20 | pages = 1851–1852 | date = November 2011 | pmid = 22083573 | doi = 10.1001/archinternmed.2011.506 | pmc = 3564588 | doi-access = free }}</ref> While the secular trend might decrease individual level risk of developing hearing loss, the prevalence of hearing loss is expected to rise due to the aging population in the US. Another concern about aging process is cognitive decline, which may progress to [[mild cognitive impairment]] and eventually dementia.<ref>{{cite journal | vauthors = Park HL, O'Connell JE, Thomson RG | title = A systematic review of cognitive decline in the general elderly population | journal = International Journal of Geriatric Psychiatry | volume = 18 | issue = 12 | pages = 1121–1134 | date = December 2003 | pmid = 14677145 | doi = 10.1002/gps.1023 | s2cid = 39164724 }}</ref> The association between hearing loss and cognitive decline has been studied in various research settings. Despite the variability in study design and protocols, the majority of these studies have found consistent association between age-related hearing loss and cognitive decline, cognitive impairment, and dementia.<ref name=":0">{{cite journal | vauthors = Loughrey DG, Kelly ME, Kelley GA, Brennan S, Lawlor BA | title = Association of Age-Related Hearing Loss With Cognitive Function, Cognitive Impairment, and Dementia: A Systematic Review and Meta-analysis | journal = JAMA Otolaryngology–Head & Neck Surgery | volume = 144 | issue = 2 | pages = 115–126 | date = February 2018 | pmid = 29222544 | doi = 10.1001/jamaoto.2017.2513 | pmc = 5824986 }}</ref> The association between age-related hearing loss and Alzheimer's disease was found to be nonsignificant, and this finding supports the hypothesis that hearing loss is associated with dementia independent of Alzheimer pathology.<ref name=":0" /> There are several hypotheses about the underlying causal mechanism for age-related hearing loss and cognitive decline. One hypothesis is that this association can be explained by common etiology or shared neurobiological pathology with decline in other physiological system.<ref name=":12">{{cite journal | vauthors = Thomson RS, Auduong P, Miller AT, Gurgel RK | title = Hearing loss as a risk factor for dementia: A systematic review | journal = Laryngoscope Investigative Otolaryngology | volume = 2 | issue = 2 | pages = 69–79 | date = April 2017 | pmid = 28894825 | doi = 10.1002/lio2.65 | pmc = 5527366 | doi-access = free }}</ref> Another possible cognitive mechanism emphasize on individual's [[cognitive load]]. As people developing hearing loss in the process of aging, the cognitive load demanded by auditory perception increases, which may lead to change in brain structure and eventually to dementia.<ref>{{cite journal | vauthors = Pichora-Fuller MK, Mick P, Reed M | title = Hearing, Cognition, and Healthy Aging: Social and Public Health Implications of the Links between Age-Related Declines in Hearing and Cognition | journal = Seminars in Hearing | volume = 36 | issue = 3 | pages = 122–139 | date = August 2015 | pmid = 27516713 | doi = 10.1055/s-0035-1555116 | pmc = 4906310 | doi-access = free }}</ref> One other hypothesis suggests that the association between hearing loss and cognitive decline is mediated through various psychosocial factors, such as decrease in [[Social relation|social contact]] and increase in [[social isolation]].<ref name=":12" /> Findings on the association between hearing loss and dementia have significant public health implication, since about 9% of dementia cases are associated with hearing loss.<ref>{{cite journal | vauthors = Ford AH, Hankey GJ, Yeap BB, Golledge J, Flicker L, Almeida OP | title = Hearing loss and the risk of dementia in later life | language = en | journal = Maturitas | volume = 112 | pages = 1–11 | date = June 2018 | pmid = 29704910 | doi = 10.1016/j.maturitas.2018.03.004 | s2cid = 13998812 | url = https://www.maturitas.org/article/S0378-5122(18)30118-X/abstract }}</ref>