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Understanding Students with Hearing Loss. Chapter 14. Cochlear Implants. What are the issues of controversy? Do you think Mariah, Ricquel, and Shylah should have an implant?. Definition. Deaf = hearing loss of 70 to 90 decibels or greater and cannot use hearing even with amplification
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Understanding Students with Hearing Loss Chapter 14
Cochlear Implants • What are the issues of controversy? • Do you think Mariah, Ricquel, and Shylah should have an implant?
Definition • Deaf = hearing loss of 70 to 90 decibels or greater and cannot use hearing even with amplification • Hard of hearing = hearing loss in the 20 to 70 dB range and benefits from amplification
Prevalence • (2003) 70,349 students ages 6-21 • 7,474 preschool ages 3-5
Hearing Process • Audition = hearing process • Vibration = interpreting patterns in the movement of air molecules • Sound is described in pitch and frequency • Frequency measured in hertz (Hz) • Loudness measured in decibels (dB)
Outer Ear • Auricle, or pinna, and ear canal • Purpose to collect the sound waves • Funnel sound waves to the tympanic membrane (eardrum) • Vibrating air hits the eardrum which causes vibration
Middle Ear • Consists of 3 little bones known as the ossicular chain= malleus (hammer), incus (anvil), and stapes (stirrup) • Vibration of the eardrum causes the bones to vibrate and transmit sound through the middle ear • Eustachian tube also in middle ear equalizes air pressure when you yawn and swallow
Inner Ear • Cochlea • Snail-shaped bony structure - multiple rows of delicate hair cells connected to auditory nerve • Vestibular mechanism • Semicircular canals that control balance
Characteristics • IQ range same as general population • Mild to severe language delays • Receptive speech impairments
Communication Options • Oral/aural communication • Amplification or cochlear implant • Emphasis on amplified sound to develop language • Manual communication • Sign language • Finger spelling • Total or simultaneous communication • Combines both sign and spoken communication
Challenges • Academic Achievement • Challenges with reading and writing • Social and emotional development • Parent -child interactions • Peers and teachers - self concept • Social cues • Sense of isolation
Causes • Congenital - present at birth • Acquired • Trauma • Disease • Exposure to excessive noise
Hereditary • 1 in 2,000 children • Result of inherited autosomal recessive gene • 70 documented inherited syndromes associated with deafness
Prenatal • Hypoxia • Rubella • Toxoplasmosis, herpes, syphilis, cytomegalovirus (CMV)
Postnatal • Bacterial meningitis • Acute otitis media (ear infections)
Postlingual Causes • Blow to the skull causing trauma to the cochlea • Excessive noise - firecrackers and air guns • Exposure to loud noise over time - rock concerts and headphones • Noise levels of 100 to 110dB • Sustained 90dB levels damaging
Hearing Tests • Evoked otoacoustic emissions: EOAE • Screening auditory brain stem response • Audimetry - ABR • Behavioral audiological evaluations - older children
An audiogram is a picture of your hearing. The results of your hearing test are recorded on an audiogram. The audiogram to the right demonstrates different sounds and where they would be represented on an audiogram. The yellow banana shaped figure represents all the sounds that make up the human voice when speaking at normal conversational levels.
The horizontal lines represent loudness or intensity. The 0 decibel (dB) line near the top of the audiogram represents an extremely soft sound. Each horizontal line below represents a louder sound. Moving from the top to the bottom would be consistent with hitting the piano key harder or turning up the volume control on your stereo.
The softest sound you are able to hear at each pitch is recorded on the audiogram. The softest sound you are able to hear is called your threshold. Thresholds of 0-25 dB are considered normal (for adults). The audiogram on the right demonstrates the different degrees of hearing loss.
Types of Hearing Loss • Conductive - air-conduction thresholds show loss but bone-conduction are normal • Sensorineural - no blockage in middle or outer ear - loss is caused by sensitivity in cochlear or auditory nerve • Mixed - both air-conduction/bone-conduction and sensitivity
IDEA Services • Interpreting services • Tutoring • General classroom assistance • Educational planning • Sign language instruction
Supplemental Aids • Sound-field amplification system • Loop systems • Assistive technology • closed captioned • C-print: real-time translations of the spoken word
http://www.dizziness-and-balance.com/testing/hearing_test.htmhttp://www.dizziness-and-balance.com/testing/hearing_test.htm • http://www.babyhearing.org/HearingAmplification/HearingLoss/audiogram.asp • http://www.hdhearing.com/Learning/Part2.htm