Fuentes:
(1) Better Hearing Institute (2018)
(2) Global Burden of Hearing Loss in the Year 2000 (WHO, 2003); Deafness and Hearing Impairment (WHO, 2006)
(3) Better Hearing Institute (2018)
(4) American Johns Hopkins University in Baltimore, Maryland (2006)
(5) Health Technology Assessment (Davis et al., 2007)