1. Addressing the Rising Prevalence of Hearing Losshttp://apps.who.int/iris/bitstream/handle/10665/260336/9789241550260-eng.pdf?sequence=1&ua=1
2. Hearing Loss in Adults
3. Prevention of Blindness and Deafness. Grades of Hearing Impairmenthttp://www.who.int/pbd/deafness/hearing_impairment_grades/en/
4. Prevention of Blindness and Deafness. Estimates. Global Estimates on Prevalence of Hearing Losshttp://www.who.int/pbd/deafness/estimates/en/
5. Deafness and Hearing Loss. Key Factshttp://www.who.int/mediacentre/factsheets/fs300/en/