1. Understanding Students with Hearing Loss
Chapter 14

2. Cochlear Implants What are the issues of controversy?
Do you think Mariah, Ricquel, and Shylah should have an implant?

3. 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

4. Prevalence
(2003) 70,349 students ages 6-21
7,474 preschool ages 3-5

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)

6. 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

7. 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

8. 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

9. Characteristics IQ range same as general population
Mild to severe language delays
Receptive speech impairments

10. 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

11. 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

12. Causes Congenital - present at birth Acquired Trauma Disease
Exposure to excessive noise

13. Hereditary 1 in 2,000 children
Result of inherited autosomal recessive gene
70 documented inherited syndromes associated with deafness

14. Prenatal Hypoxia Rubella
Toxoplasmosis, herpes, syphilis, cytomegalovirus (CMV)

15. Postnatal
Bacterial meningitis
Acute otitis media (ear infections)

16. 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

17. 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

18. 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.

19. 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.

20. 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.

21. 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

22. IDEA Services Interpreting services Tutoring
General classroom assistance
Educational planning
Sign language instruction

23. 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