Deafness and Hearing Impairment
In 2004, more than 275 million people around the world had moderate-to-profound hearing hearing impairment. According to the World Health Organization, 80 percent of those people lived in low- and middle-income countries. Hearing impairment refers to the partial and/or complete loss of the ability to hear.
- Infectious diseases (e.g., meningitis, measles, mumps, chronic ear infections) can lead to hearing impairment.
- With prevention, early diagnosis and management, half of all cases of deafness and hearing impairment are avoidable or treatable.
- Depending on the cause, hearing loss may be treated medically, surgically or with devices such as hearing aids and implantable devices.
- Hearing aid production meets less than ten percent of global need. Fewer than one out of 40 people in developing countries who need a hearing aid have one.
Types of Hearing Impairment
- Conductive hearing impairment: a problem in the outer or middle ear, often treatable with medicine or surgery.
- Sensorineural hearing impairment: a problem with the inner ear or the hearing nerve, often requiring rehabilitation for this likely permanent condition.
Causes of Hearing Impairment and Deafness
Congenital causes which can lead to deafness at or soon after birth:
- Hereditary hearing loss where deafness is inherited from a parent can lead to a higher risk of a child being born deaf.
- Hearing impairment can also be caused by complications during pregnancy and childbirth.
Acquired causes which can lead to hearing loss at any age:
- Injury to the ear or head can cause hearing impairment.
- Wax or foreign bodies blocking the ear canal can cause hearing loss, which is usually mild and treatable.
- Excessive noise or exposure to loud music can damage the inner ear.
- Infectious diseases and chronic ear infections can lead to hearing impairment during childhood or later in life.
- The use of otoxic drugs can damage the inner ear.