Teaching Students with Sensory Impairments
Definitions, Identification, and Supportive Professionals
Dolly Bhargava, M. Spec. Ed.
VIII. Hearing Assessments
A. Audiological Exam
Once the referral to the appropriate professional has been made, an audiological
examination is performed. An audiological examination is conducted by an
audiologist to determine:
1. if a hearing loss is present;
2. which tones are affected;
3. the degree of the hearing loss;
4. the type of hearing loss (i.e. conductive,
sensorineural, or mixed);
5. the best method of treating the hearing loss; including
selection of an appropriate hearing aid, if appropriate.
The audiologist begins the examination of the child by first taking a case history.
The audiologist asks questions about the child’s medical conditions, hearing
behaviors, hearing loss in the family, and any concerns of the child and the family.
The audiologist then performs several tests in order to obtain an accurate measure
of the child’s hearing abilities to determine the existence and extent of the hearing
impairment.
When these tests have been completed, the audiologist may conduct more
specialized procedures, such as the evaluation of the mechanical functioning of the
eardrum and bones of the middle ear (“intermittence teats”), and other measures to
assess the function of the cochlea. Alternatively, if deemed necessary, the
audiologist will make referrals to other professionals.
After reviewing the child’s information and test results, the audiologist will be able to
describe a hearing loss as unilateral (affecting one ear) or bilateral (affecting both
ears), the degree of hearing impairment (mild, moderate, severe or profound), and
the type of loss (conductive, sensorineural or mixed). The audiologist will make
recommendations regarding amplification and provide suggestions on how to best
manage the hearing impairment. It is important to remember that every student is
an individual and as Scheetz (2000) emphasizes, “One must be careful not to
pigeonhole or label someone based on this information” (p. 52). To help the
student we need to then individualize the supports that we provide by consulting
with other professionals.
Below is information about some of the tests that are performed to assess
hearing. They include:
A-1. Otoscopy. Otoscopy is a physical examination of the ear that involves
looking into the ear with an instrument called an “otoscope” (or “auriscope”) to
examine the structures of the outer ear and the eardrum. Otoscopy can help
detect problems such as a hole (perforation) in the eardrum and infections of
the middle ear (such as acute Otitis Media, an infection that produces pus,
fluid, and inflammation within the middle ear). The nose, nasopharynx (space
within the skull that is above the roof of the mouth, and behind the nose), and
upper respiratory tract are also examined.
A-2. Tympanometry. Tympanometry measures the ability of the middle ear
to conduct sound. It is particularly useful in detecting fluid in the middle ear;
Eustachian tube dysfunction (such as negative middle ear pressure);
disruption of the ossicles (bones); tympanic membrane (ear drum)
perforation; and otosclerosis (abnormal growth of bone in the middle ear). To
perform this test, a soft probe is placed into the ear canal and a small amount
of pressure is applied. The instrument then measures mobility of the
tympanic membrane and its response to the pressure changes. The results
of the test are printed as a graph, called a “tympanogram” which can help
identify middle ear problems. For example, a flat line on the tympanogram
may indicate that the eardrum is not mobile or not vibrating properly due to
fluid in the middle ear (Hain, 2002).
A-3. Audiometry. Audiometry is the testing of a person’s ability to hear
sounds at a range of frequencies. This includes air conduction tests, bone
conduction tests, and speech audiometry tests. An audiometric test is used
to determine the types of sounds the child can and cannot hear.
Air conduction tests involve the presentation of beeps and whistle-like
sounds, called “pure tones,” through headphones in a soundproof room.
Sounds are of varying loudness (intensity measured in dB) and of different
pitch (or frequencies measured in Hz) The pure tones go via the air, down
the ear canal, through the middle ear into the inner ear. The child is asked
to respond when he or she detects a sound (such as by raising a hand or
pushing a button). The loudness of each tone is reduced until the child
can just hear the tone. The softest sounds the child can hear constitute
the hearing threshold. This is marked on a graph called an “audiogram,”
which can be used to identify and diagnose hearing impairment (Martin &
Clark, 2003).
A bone conduction test involves using a skull vibrator such as a vibrating
tuning fork. It is placed behind the ear to measure the softest sounds that
the child can hear to test the functioning of the inner ear. The child is
asked to respond when detecting a sound produced by the device. As the
sound travels through the bones of the skull to the inner ear (cochlea,
auditory nerves), the sound sidesteps the outer and middle ear.
A-4. Interpretation of Air Conduction and Bone Conduction Results

If air conduction and bone conduction thresholds are within normal limits,
then hearing is normal.

If the air conduction thresholds indicate a loss and the bone conduction
thresholds do not indicate a loss, then a conductive hearing loss is
present. In other words a person does not hear normally when sound has
to go through the outer, middle and inner ear, but if the sound bypasses
the conductive mechanism (i.e. the outer and middle ear), and goes
directly to the inner ear, then hearing is normal.

If there is a loss by both air- and bone - conduction and the abnormal
thresholds are essentially similar, then a sensorineural hearing loss exists.
In other words, there is a hearing loss by air conduction, such as when the
sound goes through the outer, middle and inner parts of the ear. There is
the same amount of hearing loss when the sound bypasses the outer and
middle ear and goes directly to the inner ear.

If there is a loss by both air conduction and bone conduction, but the loss
by air conduction is worse than the loss by bone conduction, a mixed
hearing loss exists. Both conductive and sensorineural components are
present.
A-5. Speech audiometry. This involves presenting the child with a series
of simple recorded syllables, words and sentences spoken at various volumes
into the headphones. The test is designed to assess speech threshold (i.e.,
when the child can first hear speech) and the child’s ability to understand
speech (Scheetz, 2000). The test requires the child to repeat each word back
to the audiologist as it is heard. This provides information on the volume
(quantity) of the speech sound that the child can hear and also the quality of
the sound (clear vs. distorted) the child hears. The level at which the child
can repeat 50% of test materials correctly provides information about the type
and degree of hearing impairment (Lysons, 1996). This is useful to determine
the candidacy for hearing aid and reaffirm the findings of the pure-tone
audiometry test.
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