1. Word Hearlth Organization. Deafness and hearing loss, https://www.who.int/news-room/fact-sheets/detail/deafness-and-hearing-loss; [accessed 14 December, 2020].
2. National Institute on Deafness and Other Commmunication Disordesrs. Quick Statistics About Hearing, https://www.nidcd.nih.gov/health/statistics/quick-statistics-hearing#6; [accessed 14 December, 2020].
3. An investigation into hearing loss among patients of 50 years or older;Fei;J Otol,2011
4. Global, regional, and national incidence, prevalence, and years lived with disability for 310 diseases and injuries, 1990-2015: a systematic analysis for the Global Burden of Disease Study 2015;Vos;Lancet,2016
5. Association between hearing impairment and risk of hospitalization in older adults;Genther;J Am Geriatr Soc,2015