disability concpt

CONCEPT OF DISABILITY

The terms disability, handicap, and impairment are often used or

misused interchangeably in rehabilitation literature. Disability refers to a

physical, physiologic, mental, or sensory abnormality, whereas handicap

refers to the consequences caused by the disability. A handicap is the

extent and degree to which a disability impedes, limits, or restricts an

individual’s participation in certain activities or tasks for which a normal

body function is needed. Disability therefore results in activity limitation

or participation restriction as a result of the presence of a physical

or physiologic dysfunction that an individual may present. The

World Health Organization (1980) de¢nes an impairment as any loss or

abnormality of psychologic, physiologic, or anatomical structure or

function. The degree to which an impairment poses a handicap is a

function of the extent and degree of the impairment itself. Impairment

relates to disability in that both occur as a result of loss of function

of an anatomical or physiologic nature that limits activity or restricts

the individual’s participation. Hearing loss, for instance, causes activity

limitation (disability) and social/occupational participation restriction

(handicap).

Hearing loss is an invisible disability that a¡ects people of any

age group from neonates to older adults. Hearing impairment of any

degree or con¢guration is capable of compromising communication,

education, social functioning, and safety of the individual. The evaluation

and management of hearing loss, particularly in infants and young

and older adults, can be challenging. However, there is yet another

group of people who, apart from having hearing de¢cits, present additional

disabilities, disease processes, or dysfunctions that sometimes

further compromise the hearing loss itself. However, such additional

disease processes or conditions may be primary, secondary, or totally

unrelated to a hearing loss. These problematic conditions may be

developmental such as mental retardation, Down’s syndrome, cerebral

palsy, and autism; may be related to a disease process such as human

Overview of Disabilities 3

immunode¢ciency virus infection (HIV)/acquired immunode¢ciency

syndrome (AIDS) and other conditions that can cause the disruption

of auditory or visual function, physical motor function, or sensory

motor function; or may be disorders in speech, language, and

cognition.

Despite rapid advancement in medicine, science, and technology,

the number of people with disabilities has not yet decreased signi¢-

cantly. Natural occurrences due to chromosome defects as well as to

pre, peri, and postnatal events and traumatic accidents during delivery

have contributed to the numbers of people with disabilities in our

society. It is also possible that we now have better methods of detecting

and describing new human developmental problems and disease processes.

Some good examples of discoveries of new conditions are

AIDS and severe acute respiratory syndrome (SARS). It is simply not

possible to be familiar with every known disability. In addition, many

times clinicians do not feel they possess adequate training or skills

to evaluate hearing-impaired people with other more commonly

encountered disabilities, such as CP, visual impairment, mental retardation,

dementia, and Down’s syndrome. These disabilities may be

primary to, secondary to, or even unrelated to hearing impairment.

Very young and elderly individuals pose greater challenges for audiologic

evaluations and rehabilitation, especially if other disabilities are

present. Usually, a diagnosis of the dominant disability is important.

Based on this diagnosis, speci¢c audiologic test batteries can be

selected.

For instance, the HIV/AIDS epidemic has occurred during the past

two decades. The literature is replete with reports of structural damage

and loss of function resulting from the impact of HIV/AIDS on the

auditory system (Grimaldi, et al., 1993; Moazzez & Alvin, 1998; Pappas,

Roland, Lim, Lai, & Hillman, 1995; Soucek & Michael, 1996). New

disease processes and conditions as exempli¢ed by the recent SARS epidemic

will continue to emerge even with advancements in sophisticated

diagnostic and therapeutic methods in science and medicine to address

known and unknown pathologic conditions. Some of these pathologic

conditions may occur as handicaps that are primary to or associated with

hearing impairment. Associated or dominant handicaps in hearingimpaired

individuals may sometimes delay the diagnosis of hearing

impairment (Voutilainen, Jauhiainen, & Linkola, 1998). Until recently

4 Aural Rehabilitation of People with Disabilities

hearing impairment was often not thought to be crucial in the initial

evaluation of children with disabilities, because it was not considered

a priority in the overall rehabilitation process (Friedrich, 1985). However,

in the United States, this attitude is changing now that universal neonatal

hearing screening programs are in place in many states. In these states,

a hearing screening test is performed on every neonate before discharge

from the hospital. In addition, noninvasive and more objective tools such

as otoacoustic emissions and auditory brainstem response are now in

common use.

However, although these objective electrophysiologic tests generally

yield a more accurate status of auditory function than previously

used methods, they also have pitfalls (Worthington & Peters, 1980).

W|th behavioral assessment measures still being widely used, many

individuals with associated handicaps may still be considered to be

untestable, especially when clinicians are either uncomfortable or unfamiliar

with a dominant disability and its e¡ects on hearing function

and the evaluation process. Some of these disabilities will be discussed

brie£y later.