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.htm

http://www.babyhearing.org/HearingAmplification/HearingLoss/audiogram.asp

http://www.hdhearing.com/Learning/Part2.htm