Fact:Deafness

A person who is not able to hear as well as someone with normal hearing – hearing thresholds of 25 dB or better in both ears – is said to have hearing loss. Hearing loss may be mild, moderate, severe or profound. It can affect one ear or both ears, and leads to difficulty in hearing conversational speech or loud sounds. ‘Hard of hearing’ refers to people with hearing loss ranging from mild to severe. They usually communicate through spoken language and can benefit from hearing aids, cochlear implants and other assistive devices as well as captioning. People with more significant hearing losses may benefit from cochlear implants. ‘Deaf’ people mostly have profound hearing loss, which implies very little or no hearing. They often use sign language for communication. Causes of hearing loss and deafness The causes of hearing loss and deafness can be divided into congenital causes and acquired causes. Congenital causes Congenital causes may lead to hearing loss being present at or acquired soon after birth. Hearing loss can be caused by hereditary and non-hereditary genetic factors or by certain complications during pregnancy and childbirth, including: maternal rubella, syphilis or certain other infections during pregnancy; low birth weight; birth asphyxia (a lack of oxygen at the time of birth); inappropriate use of particular drugs during pregnancy, such as aminoglycosides, cytotoxic drugs, antimalarial drugs and diuretics; severe jaundice in the neonatal period, which can damage the hearing nerve in a newborn infant. Acquired causes Acquired causes may lead to hearing loss at any age, such as: infectious diseases such as meningitis, measles and mumps; chronic ear infections; collection of fluid in the ear (otitis media); use of particular drugs, such as some antibiotic and antimalarial medicines; injury to the head or ear; excessive noise, including occupational noise such as that from machinery and explosions, and recreational noise such as that from personal audio devices, concerts, nightclubs, bars and sporting events; ageing, in particular due to degeneration of sensory cells; wax or foreign bodies blocking the ear canal. Among children, chronic otitis media is the leading cause of hearing loss. Impact of hearing loss Functional impact One of the main impacts of hearing loss is on the individual’s ability to communicate with others. Spoken language development is often delayed in children with deafness. Hearing loss and ear diseases such as otitis media can have a significantly adverse effect on the academic performance of children. However, when opportunities are provided for people with hearing loss to communicate, they can participate on an equal basis with others. The communication may be through spoken/-written language or through sign language. Social and emotional impact Limited access to services and exclusion from communication can have a significant impact on everyday life, causing feelings of loneliness, isolation and frustration, particularly among older people with hearing loss. If a person with congenital deafness has not been given the opportunity to learn sign language as a child, he or she may feel excluded from social interaction. Economic impact In developing countries, children with hearing loss and deafness rarely receive any schooling. Adults with hearing loss also have a much higher unemployment rate. Among those who are employed, a higher percentage of people with hearing loss are in the lower grades of employment compared with the general workforce. Improving access to education and vocational rehabilitation services, and raising awareness especially among employers about the needs of people with hearing loss, would decrease unemployment rates among this group. In addition to the economic impact of hearing loss at an individual level, hearing loss substantially affects social and economic development in communities and countries.