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 Vestibular mechanism 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 Social and emotional development 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 EOAE - tests how well the cochlea is functioning, ear canal is sealed with a plastic probe, and clicks or tones of various frequencies are introduced into the ear canal, a computer records responses that are evoked from the cochlea SABR - assess the cochlea and the auditory neural pathway, EEG sensors are placed in various places on the baby’s scalp, external or inserted earphone is used, tones or clicks are presented separately to each ear stimulating neural activity along the path ABR - generates waveforms composed of three distinct waves; the absence of waveform at a given intensity suggests a hearing loss Behavioral audiological evaluations- child responds if they hear a given sound, recorded on an audiogram - a picture of what was heard

An audiogram is a picture of your hearing 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 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 Loop systems - closed-circuit wiring that sends FM signals from an audio system directly to an electronic coil in the student’s hearing aid and the receiver picks up the signal - need residual hearing for this

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