Impact of ageing on the auditory system and related cognitive functions: A narrative review
- 1Ear Science Institute Australia, Australia
- 2School of Surgery University of Western Australia, University of Western Australia, Australia
- 3School of Medicine, University of Notre Dame Australia, Australia
- 4Biomedical Sciences, Macquarie University, Australia
- 5School of Medical and Health Sciences, Edith Cowan University, Australia
Age-related hearing loss (ARHL), presbycusis, is a chronic health condition that affects approximately one-third of the world’s population. The peripheral and central hearing alterations associated with age-related hearing loss have a profound impact on perception of verbal and non-verbal auditory stimuli. The high prevalence of hearing loss in the older adults corresponds to the increased frequency of dementia in this population. Therefore, researchers have focused their attention on age-related central effects that occur independent of the peripheral hearing loss as well as central effects of peripheral hearing loss and its association with cognitive decline and dementia. Here we review the current evidence for the age-related changes of the peripheral and central auditory system and the relationship between hearing loss and pathological cognitive decline and dementia. Furthermore, there is a paucity of evidence on the relationship between ARHL and established biomarkers of Alzheimer’s disease, as the most common cause of dementia. Such studies are critical to be able to consider any causal relationship between dementia and ARHL. While this narrative review will examine the pathophysiological alterations in both the peripheral and central auditory system and its clinical implications, the question remains unanswered whether hearing loss causes cognitive impairment or vice versa.
Keywords: Age-related hearing loss (ARHL), Presbycusis, Ageing, Auditory system, cognitive functions, Dementia
Received: 18 Sep 2017;
Accepted: 15 Feb 2018.
Edited by:Stefano L. Sensi, Università degli Studi G. d'Annunzio Chieti e Pescara, Italy
Reviewed by:Aurel Popa-Wagner, Department of Neurology, University Hospital Essen, Germany
Cristina Sanchez-Castañeda, Department of Psychiatry and Clinical Psychobiology, University of Barcelona, Spain
Copyright: © 2018 Jayakody, Friedland, Martins and Sohrabi. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.
* Correspondence: Dr. Hamid R. Sohrabi, Macquarie University, Biomedical Sciences, Sydney, NSW, Australia, firstname.lastname@example.org