Facts of the Matter -- Hearing
A, R, and T
By Gilbert Ford, For Baby's Favorite Rhymes to Sign
H earing impairments, which range from partial to total hearing loss (deafness), can be inherited or caused by chronic ear infections, complications of pregnancy and childbirth, drugs that damage the ear, and diseases such as meningitis, measles, and mumps. Injuries, aging, and exposure to loud noise also can result in hearing impairment.
- About 278 million people around the world have lost most or all of their hearing in both ears. Eighty percent of them live in low- and middle-income countries such as Afghanistan, Ethiopia, Haiti, and Vietnam.
- The World Health Organization estimates that half the cases of deafness and hearing impairment worldwide can be prevented through early diagnosis and treatment, and through measures such as improved prenatal care, child immunization, the avoidance of certain medications, and the use of protective devices to reduce noise exposure.
- About 25 percent of all hearing impairment cases originate in childhood. In children, chronic middle ear infections are a leading cause.
- In the United States, more than 35 million children and adults live with some degree of hearing loss. Of those, more than 22 million between the ages of 20 and 69 have permanent damage.
- Audiologists evaluate and treat hearing- and balance-related problems. More than 100 schools in the United States teach audiology. India has 15 schools, and Indonesia recently founded its first. Bangladesh, Nepal, and Sri Lanka do not have any.
- For at least 90 percent of people with hearing impairments, hearing aids result in improved communication. However, unlike eyeglasses, which can often restore 20/20 vision, hearing aids do not return hearing to normal. They amplify all sounds, including ambient noise, and may interact with the frequency of other devices, such as cell phones.
- Hearing aid technology is improving, and many options exist for function and design. In the United States, the cost can range from $600 to $5,000 for some digital models.
- According to the World Health Organization, less than 3 percent of people in developing countries who are in need of a hearing aid have one. Hearing aid production meets less than 10 percent of the global need.
- Sign language, which involves hand movements, facial expressions, and body postures, varies from country to country, and sometimes within regions of the same nation. Sign languages and dialects include Brazilian, Chinese, Greek, Japanese, Russian, Spanish, Ugandan, Pan-Arab, and Indo-Pakistani, among others.
- The exact origins of American Sign Language are unknown, but some research shows a connection to French Sign Language. Laurent Clerc, of France, began teaching French Sign Language to American students in 1817, at the first U.S. school for the deaf in Hartford, Conn.