Tucci, Merson, and Wilson (2010) engaged in a massive literature review of hundreds of articles from 1980 to today. Among the key points addressed:
Across the globe, more than 278 million people have moderate-to-profound hearing loss in both ears, and most people who have hearing loss live in developing countries. Approximately 50 percent of all hearing loss can be prevented. Across the globe, more than 100 countries are considered “developing countries” and these same countries contain some 80 percent of the world’s population. The average expenditure on health care in developed countries is $2,716 US, whereas the average cost expenditure on health care in the “least developed” countries is $13 US. In the United States, hearing impairment costs about $170 billion per year, which is almost three percent of the gross national product. In developed countries, the incidence of congenital bilateral sensorineural hearing loss (greater than 40 dB) is estimated at 2 to 4 per 1,000 live births. In developing countries, the incidence of congenital bilateral sensorineural hearing loss (greater than 40 dB) is estimated to be not less than 6 per 1000 live births. Therefore, the authors estimate that some 720,000 children born per year with congenital bilateral sensorineural hearing loss. Tucci, Merson, and Wilson also offer information regarding hearing loss across specific regions, such as Asia, Latin America, the Caribbean, the Middle East, Sub-Saharan Africa (which contains ten percent of the world’s population and two-thirds of the world’s least developed counties).
The authors report that children with hearing loss in developing countries experience delays in development of speech, language, and other cognitive skills. Children with disabilities see physicians 1.5 times more often than children without disabilities. Children with disabilities spend 3.5 times more days in the hospital than children without disabilities. Children with disabilities experience 2 times as many missed days from school and children with disabilities have an 2.5 times increased chance of repeating a school grade than do children without disabilities.
In the United States, the authors report that communication problems are associated with higher rates of unemployment and income for people with hearing loss may be 45 percent lower than for adults without hearing loss. They report that developing countries need some 32 million hearing aids per year, yet only 750,000 or so are provided. Given the severe shortage of hearing aids in developing countries, and to maximize the benefits and distribution of the units available, the World Health Organization suggests fitting the better ear of children with pure tone averages between 31 and 80 dB first, and then (if there are) additional hearing aids (they) should be distributed to adults with a better ear pure tone average between 41 and 80 dB.
For More Information, References, and Recommendations
Tucci DL, Merson MH, Wilson B. (2010) A Summary of the Literature on Global Hearing Impairment: Current Status and Priorities for Action. Otology & Neurotology. 31(1):31-41.