Audiology Resource Notebook
• This presentation is intended as a resource for
professionals in Deaf Education, Audiology, and Speech
Pathology. It includes information about the basic
audiometric test battery, common causes of hearing loss,
and example audiograms. Each topic has its own table
of contents, and, where possible, each section of
information has an accompanying graphic.
The
information contained within the presentation is meant
to be a quick look-up guide to the most essential
information with regards to these topics. The reference
links at the end of the presentation provide more indepth information.
Audiology Resource Notebook
Katrina García
The University of Tulsa
Dr. Sharon Baker
2002
Resource Sections
• Audiometric Procedures
– Otoscopic Exam
– Pure Tone Testing
– Speech Audiometry
– Immittance Testing
• Example Audiograms
– Student Preformed Audiogram
– Types of Hearing Loss
– Audiograms That Indicate a Disorder
• Causes of Hearing Loss
– Table of Contents
Otoscopic Exam
• Using an otoscope, examine the eardrum for
any abnormalities.
Normal eardrum
TM Perforation
Return to Resource Sections
Serous Otitis Media
Pure Tone Testing
Air Conduction
• Test right ear or better ear
first.
• Begin at 1000Hz at 40dB.
• Decrease 10dB until there is
no response.
• Go up 5dB to zero in.
• Threshold is established
when client responds 50% of
the time.
• O indicates right ear
• X indicates left ear
Pure Tone Testing Continued
Bone Conduction
• Procedure is the same.
• < indicates right ear.
• > indicates left ear.
• Air conduction indicates
amount of loss.
• Bone conduction
indicates type of loss.
Return to Resource Sections
Air Bone Gap
• If there is no air bone gap, and
there is loss, then the loss is
sensorineural.
• If there is an air bone gap of
more than 10dB, and bone
conduction is normal, it is a
conductive loss.
• If there is an air bone gap of
more than 10dB and bone
conduction and air conduction
both indicate a loss, the loss is
mixed.
Speech Audiometry
Speech Reception Threshold (SRT)
•
•
•
•
Spondees are the speech stimuli.
Start at 40dB, ask client to repeat spondee.
Establish threshold using the down 10dB, up 5dB method.
Compare to the average of the pure tone values at 500, 1000, and
2000Hz. If there is a sharp decline in one value, use the best two.
• Should be within 15dB of Pure Tone Average (PTA). If not,
suspect a problem with the pure tone results.
• A spondee board can be used for inarticulate clients.
• Speech Awareness Threshold (SAT) is used when client is deaf.
In this case, a repeated syllable is used and the client is asked to
indicate when they can perceive the sound.
Speech Audiometry Continued
Word Recognition Score (WRS)
• The stimuli are a list of 25-50 phonetically balanced one
syllable word.
• Present every word at the same loudness and say it only
once.
• Ask client to repeat word after it is said.
• Use 25-50 words for each ear and mark how many words
are repeated correctly.
• Calculate percentage of words recognized. 100-96% is
excellent.
Return to Resource Sections
Immittance Testing
Tympanometry
• The tympanogram is a plot of middle air pressure vs. TM
compliance.
• There are three types of tympanogram:
Type A
Type B
Type C
Immittance Testing Continued
• Type A is normal, and indicates the mobility of the ear
drum.
– Type A has two subtypes. Type AD indicates a great deal of flexibility.
Type As can indicate that the eardrum’s movement is being restricted.
• Type B indicates fluid in the middle ear.
• Type C indicates low air pressure in the middle ear.
– The eustachian tubes are not letting enough air through
– Can lead to a fluid filling the ear.
Return to Resource Sections
Student Performed Audiogram
• Performed 12-6-01
• Client: E. S., age 17 (DOB
12-28-83)
• Examiner: Katrina García
• SAT: 80dB, 75dB
Comments: Client has a bilateral
mixed loss with recruitment that
is moderately severe to
profound. SAT is consistent
with audiogram. Cause of
deafness is unknown and most
likely congenital.
Return to Resource Sections
Conductive Loss
Return to Pure Tone Testing
Sensorineural Loss
Return to Pure Tone Testing
Mixed Loss
Return to Pure Tone Testing
Return to Resource Sections
Audiograms That Indicate
a Disorder
• Otosclerosis
• Presbycusis
• U-Shaped
– Treacher Collins
– Rubella
• Noise-Induced Hearing Loss
Return to Resource Sections
Noise-Induced Hearing Loss
Noise-Induced hearing loss is indicated by high frequency loss
usually of 4000Hz or higher
Return to Audiograms
Table of Contents
• Disorders/Conditions • Infections
–
–
–
–
–
–
–
–
Atresia
Ceruminosis
TM perforation
Barotrauma
Otosclerosis
Presbycusis
Cleft Palate
Multiple Sclerosis
– Otitis externa
– Otitis media
– Labyrinthitis
• Tumors
– Cholesteatoma
– Vestibular
Schwannoma
Table of Contents Continued
• Syndromes
– Alport syndrome
– Down syndrome
– Waardenburg
syndrome
– Usher syndrome
– Treacher Collins
syndrome
– Meniere’s disease
• TORCH Complex
–
–
–
–
–
Toxoplasmosis
Congenital Syphilis
Rubella
Cytomegalovirus
Herpes Simplex
Previous Page
Return to Resource Sections
Atresia
• Atresia is the absence of • In most cases there is a
an external ear canal.
bony plate the separates
the external ear from the
• Is almost always
contents of the middle
accompanied by
ear.
abnormalities in the
outer and middle ear.
• Conductive loss, bone
conduction hearing aids
are used.
Atresia without • Can be surgically
microtia.
corrected in some
instances.
Return to Table of Contents
Cerumenosis
• Buildup of the wax
(cerumen) in the outer
ear canal.
• Can be caused by overproductive cerumen
glands, but is most often
caused when attempts to
clean the ear pushes wax
deeper into the canal
• Causes conductive
hearing loss.
• Can usually be cleared
up with drops that soften
the wax.
• Complications that can
occur include: TM
perforation, otitis media,
otitis externa, and
permanent hearing loss.
Return to Table of Contents
TM Perforation
• A hole or rupture in the
eardrum.
• Causes conductive hearing
loss, the larger the
perforation the greater the
loss
• Pain is usually not present.
• Causes usually trauma or
infection.
– Picture of TM perforation due
to trauma
– If caused by otitis media, there
may be infected or bloody
drainage.
• Most perforations will
heal spontaneously within
weeks of rupture. During
healing, ear must be
protected from water and
trauma
• On rare occasions a small
hole may remain after PE
tubes have fallen out or
been removed
Return to Otoscopic Exam
Return to Table of Contents
Barotrauma
• Discomfort in the ear
caused by pressure
differences between the
outer and middle ear.
• Barotrauma can occur
when flying, scuba diving,
and changing altitude.
• Symptoms include pain,
slight conductive hearing
loss, and ear fullness
Return to Table of Contents
• If severe or prolonged, can
cause moderate to severe
hearing loss, feeling of
pressure in the ears,
nosebleed and middle ear
pain.
• Otoscopic exam may
show slight bulge or
retraction of the eardrum.
• Severe barotrauma may be
hard to distinguish from
otitis media.
Otosclerosis
• Otosclerosis is the growth of
spongy bone-like tissue
around the footplate of the
stapes and blocks the oval
window.
• There are several types:
– Subclinical does not interfere
with the ossicles
– Histologic may or may not
cause hearing loss
– Clinical can be present in
teen years, but may not be
noticed until adulthood
• Causes gradual conductive
hearing loss progressing
from the low frequencies, to
the high frequencies, and
then to the middle
frequencies.
• Can also cause sensorineural
loss in the high frequencies,
this type is known as
cochlear otosclerosis.
• Can begin unilaterally and
progress to a bilateral loss
Otosclerosis Continued
• Maximum conductive loss is
between 50-60dB, with a
mixed loss it will increase to
60-70dB.
• Usually occurs between the
ages of 30 and 50, but can
occur as early as late
childhood.
• Women are more likely to
develop a hearing loss from
otosclerosis than men.
• Women may notice a
decrease in hearing after
pregnancy due to hormonal
changes.
• Most likely has a genetic
component.
• Conductive loss can be
corrected with a
stapedectomy which replaces
the damaged stapes
Audiogram: Otosclerosis
One of the characteristic features of an audiogram that
indicates otosclerosis is a smaller air bone gap at 2000Hz.
This is known as a Carhart notch.
Return to Audiograms
Return to Table of Contents
Presbycusis
• Hearing loss associated
with the degenerative
effects of aging.
• It affects 30-35% of adults
between 65 and 75 and
increases to 40-50% of
those over 75
• Loss is sensorineural and
in the high frequencies
• Tinnitus may occur
• There is a central auditory
component that will result
in lower WRS than
expected
• Client reports that the
speech of others sounds
slurred or mumbled
• Conversations are harder
to hear when there is
background noise.
Audiogram: Presbycusis
Audiograms that indicate presbycusis show a sharp drop
off in the frequencies above 2000Hz.
Return to Audiograms
Return to Table of Contents
Cleft Palate
• Children with a cleft
palate have more ear and
sinus infections
• Causes conductive hearing
loss due to improper
drainage of the middle ear
• Chronic otitis media can
result in a language delay
• 5% of cases occur with
syndromes, including
Treacher Collins
Return to Table of Contents
Bilateral cleft palate and cleft lip
Multiple Sclerosis (MS)
• 6% of MS patients experience hearing loss
• In rare cases hearing loss is the first
symptom of MS
• It causes a fluctuating sensorineural loss
• Hearing loss may take place when MS
flares
• Results from an ABR will not be consistent
or repeatable
Return to Table of Contents
Otitis Externa
• Inflammation of the
ear canal, also known
as swimmer’s ear.
• Can be caused by
fungi, mold, or
bacteria
• Symptoms include
pain, itching, tender
tragus, fever, swelling,
and discharge
Malignant Otitis Externa
• Occurs in elderly
diabetic patients, can
occur in AIDS patients
• Characterized by
persistent and severe
earache, foul-smelling
purulent otorrhea, and
granulation tissue in
the ear canal.
• Caused by the bacteria
Pseudomonas aeruginosa
• Causes varying
degrees of conductive
hearing loss
• Effects the facial nerve
in severe cases
• Has a mortality rate of
about 50%
Return to Table of Contents
Otitis Media
• Inflammation of the middle ear
• Most common cause is eustachain tube
dysfunction
– Occurs most often in children under 3 years of age
because of horizontal position of eustachain tubes
– Occurs as a complication of a cold, sore throat, or
other upper respiratory infections
• Can occur with or without fluid (effusion)
• Effusion can occur with or without infection
Otitis Media Continued
Serous otitis media is
characterized by thing watery
fluid that is free from
infection
• Symptoms include ear fullness
and hearing loss
Suppurative otitis media is
characterized by fluid that
contains puss. It is indicative
of infection.
• Symptoms include fever, ear pain,
hearing loss, ear fullness, dizziness,
nausea, and bulging red or yellow
eardrum
Return to Otoscopic Exam
Otitis Media Continued
Mucoid fluid is sometimes
seen with a low grade
infection.
Adhesive otitis media, or glue
ear, is characterized by a thick,
sticky effusion that causes the
eardrum to become severely
retracted.
Return to Table of Contents
Labyrinthitis
• Inflammation of the
membranous labyrinth and
semicircular canals of the
inner ear
• Can occur following otitis
media, or an upper
respiratory infection
• Symptoms include
tinnitus, dizziness, vertigo,
nausea, loss of balance,
and hearing loss
• Hearing loss and
vestibular impairments
caused by bacterial
labyrinthitis are often
permanent
• The damage caused by
viral labyrinthitis may or
may not be permanent
Return to Table of Contents
Cholesteatoma
• A collection of skin, skin
tissue, and debris in the
epitympanic recess of the
middle ear
• Is associated with chronic
otitis media and TM
perforation
• Symptoms include foul
smelling otorrhea, middle
ear pressure, and hearing
loss.
Cholesteatoma Continued
• Cholesteatoma can be congenital, but is
most often associated with ear infections
• Causes conductive hearing loss
• Can erode ossicular chain
• Can be life-threatening because it can erode
bone between the middle ear and the brain,
causing meningitis
• Must be removed surgically
Return to Table of Contents
Vestibular Schwannoma
• A tumor on the Schwann
cells of the vestibular
portion of the auditory
nerve
• Usually starts in the
internal auditory canal
• Very slow growing
• Unilateral 95% of the time
• Symptoms include hearing
loss, tinnitus, vertigo, and
facial numbness and
twitching
• Hearing loss is due to
compression or infiltration
of auditory nerve
• Loss begins with the high
frequencies
• Can lead to total deafness
in the tumor ear
• Atypical forms of hearing
loss are common
• SRT is out of proportion to
pure tone results
Vestibular Schwannoma
Continued
Itracanalicular
Vestibular
Schwannoma
Small Vestibular
Schwannoma
Return to Table of Contents
Large Vestibular
Schwannoma
Alport Syndrome
• Genetic condition that is
X-linked (85%),
Autosomal recessive
(15%), and autosomal
dominant (<1%)
• Symptoms include renal
disease, eye disorders,
blood platelet defects,
and bilateral
sensorineural hearing
loss
• Hearing loss can be
progressive and delayed
in onset
• Loss is usually mild to
moderate
• Usually diagnosed by
testing for blood or
protein in urine
Return to Table of Contents
Down Syndrome
• Caused when a child has three #21 chromosomes instead
of two
• Symptoms include characteristic facial features, congenital
heart disease, upper respiratory infections, mental
retardation of varying degrees, recurrent otitis media, and
conductive or mixed hearing loss
• 60-80% of children with Down
Syndrome experience hearing loss
• Life expectancy of a person with Down
Syndrome is 55 years
Return to Table of Contents
Waardenburg Syndrome
• There are four types of
Waardenburg Syndrome
• It is autosomal dominant
• Symptoms include wide
set eyes, white forelock
that can extend to the
skin, different
pigmentation in each
eye, and sensorineural
hearing loss
• Type I has a 20% chance
of non-progressive
sensorineural hearing
loss both unilaterally
and bilaterally that is
mild to profound
• Type II has a 50%
higher chance for
unilateral sensorineural
loss
Audiogram: Waardenburg
Characteristic audiogram shapes
include low frequency U shaped
losses, and sometimes a
combination of low frequency
sensorineural loss in one ear and
profound loss in another
Return to Table of Contents
Mild to moderate U-shaped loss
Return to Audiograms
Usher Syndrome
• Autosomal recessive
• Characterized by moderate to profound sensorineural
loss with progressive vision loss from Retinitis
pigmentosa
• Hearing loss can be congenital (severe to profound) or
progressive
• Types of blindness include night blindness, difficulty
adjusting to changes in light conditions, and tunnel
vision
• Children with these types of losses may at first be
described as clumsy
Return to Table of Contents
Treacher Collins
• Autosomal dominant
• Characterized by facial
nerve abnormalities,
craneofacial anomalies
including outer and
middle ear deformities
(microtia, atresia,
preauricular tags or pits,
stenosis)
• Mental function is normal
• Hearing loss is conductive
or mixed
Return to Table of Contents
Meniere’s Disease
• Characterized by:
–
–
–
–
episodic vertigo
roaring tinnitus
sensation of ear fullness
fluctuating and
progressive low-frequency
sensorineural hearing loss
• May be caused by
endolymphatic hydrops
• Is rarely reported in
children
Return to Table of Contents
Toxoplasmosis
• Parasitic infection
transmitted across the
placenta
• Can be present in raw
meet, raw eggs, and cat
feces
• Greatest risk to baby
during the first trimester
• Mother is asymptomatic
• Causes congenital
sensorineural loss that is
mild-profound
• As much as 10-20% of
congenital deafness is
contributed to
toxoplasmosis
• Also causes mental
retardation,
hydrocephalus, vision
loss, seizures, and neuromuscular problems
• Can be treated with
antiparasitic drugs both
prenatally and postnatally
Return to Table of Contents
Congenital Syphilis
• Bacterial sexually
transmitted disease
• Mother can be treated
with antibiotics during
pregnancy
• Child is asymptomatic
at birth and may not
manifest disease for
several decades
• Hearing loss is
extremely varied
• Audiograms show odd
configurations of
varying degrees
• Clients tend to have a
much poorer WRS
than indicated by
audiogram
Return to Table of Contents
Rubella
• Viral infection the
crosses the placenta
• Worst if contracted
during the first trimester
• Mother is asymptomatic
• Causes visual
cataracts,heart disease,
bilateral sensorineural
hearing loss, mental
retardation
Return to Table of Contents
Causes a u-shaped loss
Return to Audiograms
Congenital Cytomegalovirus
(CMV)
• The most common viral
cause of congenital
hearing loss
• Easily transmitted, as
much as 80% of the
population in the US
may be carriers
• 40-50% of infected
mothers will pass CMV
on to their infants
• 90% of infants are
asymptomatic at birth,
those who are not have a
30% mortality rate
• Causes vision loss,
progressive
sensorineural hearing
loss, and mental
retardation
Return to Table of Contents
Herpes Simplex
• Viral sexually
transmitted disease
• Infants born through
and infected birth
canal have a 50%
mortality rate
• Infants are
symptomatic at birth
• Causes spontaneous
abortion,
microcephely,
sensorineural hearing
loss, problems with
the Central Nervous
System, and mental
retardation
Return to Table of Contents
Resources
Information gathered from the following linked websites.
About Deafness
Otitis Media Information
Atlantic Coast Ear Specialists
Otosclerosis
Atresia Information
Presbycusis Information
Audiogram Types
Treacher Collins Syndrome Pictures
Audiology Net
Tympanometry Information
Cholesteatoma Information
Vestibular Schwannoma Information
Cleft Palate Information
Vestibular Schwannoma Pictures
Meniere’s Disease Information
Waardenburg’s Syndrome Pictures
MyHearing.org
Otitis Externa Information