Impairment, disorder, and disability are terms introduced by the World Health Organization (WHO) in 1980. In the WHO classifications, impairment is defined as an abnormality of a structure or function (e.g., an abnormality of the ear or auditory system). Disability is the functional consequence of impairment (e.g., inability to hear certain sounds or Inability to speak clearly). Handicap is the social consequence of impairment (e.g., isolation, loss of job, or having to make career changes as a result of communication difficulties). By applying the WHO definitions, distinctions are made that apply to how one functions as a result of an impairment. Not all impairments result in disabilities. One may also be disabled but not handicapped.
Some refer to hearing loss as congenital or acquired. If a hearing loss is congenital, it is thought to have been present at birth, associated with the birth process, or to have developed in the first few days of life. An acquired hearing loss is one that has not been present at birth but developed later, either during childhood or adulthood.
Some refer to hearing loss as being pre-lingual or post-lingual. A pre-lingual hearing loss occurs before the acquisition of language and speech. A post-lingual hearing loss is one occurring after developing a first language.
Some disorders of hearing may not necessarily involve a loss of hearing acuity but rather difficulty listening and processing sounds that are heard. Thus, the term (central) auditory processing disorder (CAPD) is used.
Persons with hearing loss may use a variety of terms to describe themselves. Terms that have general acceptance among some, but not all, individuals with hearing loss include hard of hearing, hearing impaired, late deafened, Deaf, and deaf.
Persons who are hard of hearing would preferred to be referred to as just that - "hard of hearing". The term "hearing impaired" is viewed as negative; after all, people with hearing loss are not necessarily "impaired."
Individuals in the deaf community and of the Deaf culture use the term Deaf or the capitalized "D" to denote their identity as a member of the Deaf culture. Other individuals who may be deaf, but who may not identify with the Deaf culture, might use the term "deaf" with the lower case "d."
Today the World Health Organization (WHO) is revising their classification to view an individual's circumstances along the dimensions of body function/structure and activity/participation.
Because of a problem or impairment in body function or structure (e.g., hearing loss), an individual may or may not- have difficulty in the performance of activities (e.g., communicating, listening, speaking).
Participation refers to an individual's involvement in life situations and society's response or reaction to the individual's level of functioning.
With our example of hearing loss, the question becomes "How does the person's difficulty with the activities of hearing restrict participation in life situations"?
For more information about the WHO International Classification of Functioning and Disability, see the website of the World Health Organization: http://www.who.int/en/.
Looking at hearing and its disorders from the perspective of the World Health Organization helps us understand that each person's hearing loss is different and affects each one differently in terms of what the person can and cannot do as a result of the hearing loss.
In a position statement, Hearing Loss: Terminology and Classification, (1997) , developed by the Joint Committee of ASHA and the Council on Education of the Deaf (CED), one can understand why the WHO perspectives are so important in understanding the impact of hearing loss on a person's life.
The position statement is based on the following assumptions:
- Individuals who are deaf or hard of hearing constitute a heterogeneous population.
- The relationship that exists between an individual's hearing level lnd that individual's ability to develop a language or languages in one or more communication modalities varies among individuals.
- A variety of factors affect the communication function of individuals with hearing loss. These include, but are not limited to, the presence of other disabilities related to vision, fine and gross motor functioning, and/or cognitive functioning.
- Factors such as the age of the individual when the hearing loss occurred, when the hearing loss was identified, the type of intervention/educational services available, and when those services were initiated influence communication choices.
- Family, cultural values, and community support of individuals with hearing loss can have a strong impact on the individual. This can include but is not limited to access to language, communication approaches, and use of remaining hearing and spoken or signed languages.
- Individuals with hearing loss often interact differently depending on their work, education, community, and social environment. The presence or absence of and access to interpreters, appropriate technology, and communication partners influences communication.