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Hearing Disabilities
Learners Who Are Deaf or Hard
of Hearing
• Overview- Isolation can accompany a
hearing loss
• Controversy concerning whether children
should be educated to communicate orally
or through manual sign language
• Some do become fluent enough in spoken
English to function in mainstream society
• Many members of the Deaf community
consider themselves part of a cultural
minority rather than disabled
Definition and Classification
• Decibels- units of relative loudness of sounds
• Congenitally deaf- deafness that is present at
birth; can be caused by genetic factors
• Adventitiously deaf- deafness that occurs
through illness or accident in an individual who
was born with normal hearing
• Prelingual deafness- deafness that occurs
before the development of spoken language
• Postlingual deafness- deafness occurring after
the development of speech and language
Degrees of Hearing loss
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Mild- 26-54 db.
Moderate- 55-69 db.
Severe- 70-89 db
Profound- 90 and above
Prevalence
• Differences in definition, populations
studied, and accuracy of testing contribute
to varying figures
• U.S. Dept. of Education estimate that
about .14 percent of the population from 617 years of age is identified as deaf or
hard of hearing
Anatomy and Physiology of the Ear
• The Outer Ear
– Tympanic membrane (eardrum)- Anatomical
boundary between the outer and middle ears;
the sound gathered in the outer ear vibrates
here
– Auricle- The visible part of the ear; cartilage;
collects sounds
The Middle Ear
• Ossicles- three tiny bones (malleus,
incus, and stapes) that make a transfer of
sound waves from the eardrum to the oval
window
– Mallues- hammer-shaped bone
– Incus- anvil-shaped bone
– Stapes- stirrup
– Oval Window- The link between the middle
and inner ears
The Inner Ear
• Vestibular mechanism- located in the
upper portion of the inner ears;
responsible for sense of balance
• Cochlea- snail-shaped organ that lies
below the vestibular mechanism, converts
the sounds into electric signals that are
transmitted to the brain
Diagram of the ear
Measurement of Hearing Ability
• Screening Tests
– Otoacoustic emissions- low-intensity sounds
produced by the cochlea in response to auditory
stimulation; used to screen hearing problems in
infants and very young kids
– Pure-Tone Audiometry- a test where tones of
various intensities and frequencies are presented to
determine a person’s hearing loss
– Speech Audiometry- technique that tests a person’s
detection and understanding of speech
Tests for Young and Hard to
Test Children
• Speech reception threshold (SRT)- the
decibel level at which a person can
understand speech
• Play audiometry- use of a game-like
format to test hearing of young and hard to
test children.
• Tympanometry- a method of measuring
the middle ear’s response to pressure and
sounds
Causes
• Conductive- transfer of sound in outer or middle
ear
• Sensorineural- inner ear
• Mixed Hearing Loss- combination of both
• Hearing Loss and the Outer Ear
– External otitis-swimmer’s ear (infection)
• Hearing Loss and the Middle Ear
– Otitis media
• Hearing Loss and the Inner Ear
– Congenital cytomegalovirus
Psychological and Behavioral
Characteristics
• English Language and Speech
Development- English vs, ASL
• Intellectual Ability-difficulty in testing
• Academic Achievement-deficits
• Social Adjustment- based on
communication
Educational Considerations
• Oral Approach: Auditory-Verbal Approach
and Speechreading
• Total Communication
– http://www.masterstechhome.com/ASLDict.html
• The Bicultural-Bilingual Approach
• Service Delivery Models
• Technological Advances
Early Intervention
• Critical-language development-oral vs.
manual
• Children with deaf parents develop
language (ASL) faster
Transition to Adulthood
• Postsecondary Education
– Gallaudet University
– Traditional univrsities
• Family Issues
– 95% choose deaf spouses
– 90% of their offspring can hear