Hearing Loss and Deafness 173aids must also be replaced. Second, hearing aids are usually worn most of the time, whereas many
persons wear glasses only for reading or driving. Third, many eyeglass hearing aids have large
temple positioning arms and tend to be unfashionable.
There are two general va ri e ties of ear hearing aids: behind the ear and in the ear. (Other
descriptive terms are full shell, half shell, canal, mini- canal, and completely in the canal, with the
name indicating the location of the electronic equipment.) Behind- the- ear hearing aids were once
the type most often used. These aids are obtrusive, however, and many hard- of- hearing persons
refuse to wear devices that draw attention to their disorder. Because of improved miniaturization
and digital technology, in- the- ear (partial or complete) hearing aids now provide almost invisible
aided hearing. An added advantage of in- the- ear and completely- in- the- canal hearing aids is that
there is less wind noise because the microphone is seated within the ear canal (Mueller & Car ter,
2002).
Cochlear Implants
The first human cochlear implant occurred in 1972; initially, it was available only to adults with
profound acquired hearing loss (Nelson, 2000). Now it is provided to children and adults meeting
the guidelines of the Food and Drug Administration. According to Nelson (2000), candidates must
have bilateral profound sensorineural hearing loss (adults may have bilateral severe to profound
hearing loss if acquired after the development of speech and language), limited or no useful benefit
from hearing aids, and no medical contraindications. Children and their caregivers must have
high motivation, realistic expectations, and educational placement that emphasizes auditory skills
development. Children must be at least 18 months of age and adults at least 17 years old.
The cochlear implant allows direct stimulation of the auditory nerve. The internal receiver,
consisting of wire electrodes placed in the scala tympani within the cochlea, is implanted under
the skin (Martin & Clark, 2003). Holmes (2002) describes the surgery:
The cochlear implant surgery is completed under general anesthesia. Typically, the surgeon
makes an incision behind the ear and drills a small area in the mastoid bone for the place-
ment of the receiver simulator and the insertion of the electrode array. The electrode array
is then threaded through the mastoid and the middle ear cavity and then inserted in the
scala tympani of the cochlea through the round win dow. Insertion depths can range up to
30 mm depending on the implant system being used. The operation normally ranges from
1 to 3 hours and often is done on an outpatient basis. (p. 82)After surgery, the patient receives aural habilitation or rehabilitation to maximize the implant’s
benefits. The costs of cochlear implants and related ser vices are usually covered by major insur-
ance carriers and Medicare. In some states, Medicaid and Vocational Rehabilitation Ser vices also
cover these costs (Holmes, 2002).
Aural Habilitation and Rehabilitation
The concepts of habilitation and rehabilitation, although related, differ technically. Habilitation
is the development of a person’s function or the ability to perform normally or near normally.
Rehabilitation is the restoration of function after a disorder or disease to normal or near- normal
status. For the deaf neonate, aural habilitation involves the development of optimal existing com-
munication abilities. For the youngster or adult who becomes deaf or hard of hearing after having
functional hearing, aural rehabilitation consists of the effective use of residual hearing, including
the memory of audition, as a catalyst for optimal communication. Although the objectives are
similar, relearning a function after having lost it is dif fer ent from learning a new one for the first
time. Because of the technical differences between aural habilitation and rehabilitation, the follow-
ing discussion is separated into ser vices for children and adults.