Hearing

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Hearing

• Chapter 12
• Nannette Mentzer

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Hearing

• Defining Sound
• The Hearing System
• Hearing Loss
• Identification of Hearing Loss
• Hearing Screening and Testing
• Degrees of Hearing Loss
• Treatment of Middle Ear Disease
• Treatment of Hearing Loss
• Early Intervention
• Amplification
• Communication and Education

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When we hear sound we are interpreting a pattern
of vibrating air molecules referred to as
frequency. This frequency of sound is perceived
as pitch and is measured in cycles per second or
Hertz. The more cycles the higher the frequency.
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The Hearing System
The ear is divided into a peripheral auditory
mechanism, which starts at the outer ear and ends
at the auditory nerve. The central auditory
system extends the auditory nerve to the brain.
The defect in the peripheral system would
indicate a hearing loss.
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The peripheral auditory system
External
l Auricle and the ear canal
Middle Ear
Ear canal, eardrum (tympanic membrane), stapes,
malleus, and incus (the ossicles), Eustachian
tube, the oval window,
Inner Ear
The vestibular system and the cochlea
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Hearing Loss
Conductive Dysfunction of the middle or external
ear Sensorineural dysfunction of the auditory
nerve or the cochlea Mixed hearing loss there are
conductive and sensorineural components to the
hearing loss
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Causes

• Injury in utero, perinatal or after birth
• prenatal and postnatal infections
• anoxia
• prematurity
• exposure to ototoxic agents (antibiotics)
• ear infections (conductive HL)

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Genetic disorders associated with hearing loss
Treacher Collins Syndrome Waardenburg
Syndrome Laurence-Moon-Beidi Syndrome Usher
Syndrome CHARGE Syndrome Down Syndrome Trisomy
13, Trisomy 18 Cleft Palate
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Indications of Hearing Loss
Not making reduplicated sounds Not babbling A
baby does not awaken by loud noises Not following
a verbal direction Not localizing
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Which infants get screened for a hearing loss?
According to the Joint Committee on Infant
Hearing the risk factors are family
history infections such as rubella and
syphilis bacterial meningitis congenital
malformations of the head and neck prematurity ano
xia hyperbilirubinemia requiring exchange
transfusions
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Hearing Tests
Formal hearing tests tell whether there is a
hearing loss, differentiate between conductive
and sensorineural losses, determine the degree of
the loss, estimate how speech speech sounds can
be discriminated
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Early Intervention
Children need to be linked up with an
interdisciplinary, comprehensive early
intervention program.
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Amplification
Children should be aided with a hearing aid that
works best for them. Assistive listening devices
should be explored as well as the hearing aid
when the child is included in the classroom.
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Surgery
Cochlear implants should be considered for
children that do not benefit from amplification.
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