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

• 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 6-17 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.masterstech-home.com/ASLDict.ht

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• 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