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Understanding Audiograms & Types of Hearing Loss
JF Lapeña, Jr. MA, MD, FPCS, FPSOHNS, FPAHNS
This presentation was based on material from:
AuDStudent.com Tutorial on Understanding Audiograms
Copyright 2001, AuDStudent.com Available from:
http://audsim.com/tutorials/audiotutorial1/AudiogramTutorial1.htm
http://audsim.com/tutorials/audiotutorial2/AudiogramTutorial2.htm
(Accessed 2011 January 11)
This material is meant to facilitate private understanding of the
tutorial and should not be reproduced for any other purpose.
Objectives
At the end of this session, participants will learn:
• The basic parts of the ear and their relation to hearing
• The definitions of hearing loss types:
– Conductive, Sensorineural, Mixed
• What air- and bone-conduction testing do, and how this relates
to these types of losses
• The severity of loss scales
• How to recognize basic audiometric symbols and interpret
simple audiograms
• How to recognize the basic uncomplicated forms of conductive,
sensorineural and mixed hearing loss on audiograms
Question: Parts of the Ear and Hearing
Label the parts of the ear and their role in hearing
Question: Air-conduction testing
Air-conduction testing is completed using
1. either earphones or soundfield speakers
2. a bone vibrator (bone oscillator)
Air-conduction testing sends sound
a) through the outer ear, through the middle ear,
to the inner ear where it becomes a nerve impulse
b) directly to the middle ear, where it then travels
to the inner ear and becomes a nerve impulse
c) directly to the inner ear, where it then becomes
a nerve impulse
d) directly to the nerve of hearing
Air-conduction testing
Question: Bone-conduction testing
Bone-conduction testing is completed using
1. either earphones or soundfield speakers
2. a bone vibrator (bone oscillator)
Bone-conduction testing sends sound
a) through the outer ear, through the middle ear,
to the inner ear where it becomes a nerve impulse
b) directly to the middle ear, where it then travels
to the inner ear and becomes a nerve impulse
c) directly to the inner ear, where it then becomes
a nerve impulse
d) directly to the nerve of hearing
Bone-conduction testing
Question: Conductive Hearing Loss
The definition of a conductive loss is one that:
1. occurs in the outer or middle ear
2. occurs in the cochlea
3. occurs because of damage to the nerves of hearing
4. occurs either because of damage to the cochlea or
nerves of hearing
5. both 1 and 4
Conductive Hearing Loss
Question: Mixed Hearing Loss
The definition of a mixed loss is one that:
1. occurs in the outer or middle ear
2. occurs in the cochlea
3. occurs because of damage to the nerves of hearing
4. occurs either because of damage to the cochlea or
nerves of hearing
5. both 1 and 4
Mixed Hearing Loss
Question: Abnormal Air Conduction
Abnormal Air Conduction tells you:
a) the severity of the loss
b) how much of the loss is conductive
c) how much of the loss is sensorineural
d) how much of the loss is either sensorineural or
conductive
Abnormal Air Conduction
Question: Abnormal Bone Conduction
Abnormal hearing thresholds that occur when
testing via bone-conduction tell you:
a) the severity of the loss
b) how much of the loss is conductive
c) how much of the loss is sensorineural
d) how much of the loss is either sensorineural or
conductive
Abnormal Bone Conduction
Question: Understanding Audiograms
When viewing an
audiogram,
what do the two axis
mean?
Which one is pitch and
which one is
loudness?
What are the technical
terms for pitch and
loudness?
Question: Understanding Audiograms
• What does 0 dB
HL mean?
• What does a
negative number
of decibels mean?
Question: Understanding Audiograms
• What is the range
of normal
hearing?
• Is it different for a
child versus an
adult?
Understanding Audiograms
Question: Understanding Audiograms
What are the
degrees of hearing
loss severity,
and where do
they fall on the
audiogram?
Understanding Audiograms
Question: Sensorineural Hearing Loss
If the loss is sensorineural , what is the relationship of the air- and
bone- conduction thresholds?
a. There is a loss by air conduction, but not by bone conduction.
b. There is a loss by bone conduction, but not by air conduction
c. There is a loss by both air and bone conduction, and the
thresholds are essentially the same by air and by bone
conduction.
d. There is a loss by both air and bone conduction, but the
loss by air conduction is worse than the loss by bone
conduction
Question: Conductive Hearing Loss
If the loss is conductive , what is the relationship of the
air- and bone- conduction thresholds?
a. There is a loss by air conduction, but not by bone conduction.
b. There is a loss by bone conduction, but not by air conduction
c. There is a loss by both air and bone conduction, and there
thresholds are essentially the same by air and by bone
conduction.
d. There is a loss by both air and bone conduction, but the loss
by air conduction is worse than the loss by bone conduction
Conductive Hearing Loss
Question: Mixed Hearing Loss
If the loss is mixed, what is the relationship of the
air- and bone- conduction thresholds?
a. There is a loss by air conduction, but not by bone conduction.
b. There is a loss by bone conduction, but not by air conduction
c. There is a loss by both air and bone conduction, and there
thresholds are essentially the same by air and by bone
conduction.
d. There is a loss by both air and bone conduction, but the loss
by air conduction is worse than the loss by bone conduction.
Mixed Hearing Loss
Question: Air – Bone Gap
What is an “air-bone” gap?
a. It is when air conduction thresholds are significantly
better than bone-conduction thresholds.
b. It is when bone-conduction thresholds are significantly
better than air conduction thresholds.
Question: Air – Bone Gap
What is a “significant” air bone gap?
One that is at least ___ dB
What does it mean when there is a significant air-bone gap?
a. It just tells you there is a loss
b. It tells you how much of the loss is conductive
c. It tells you how much of the loss is sensorineural
d. It tells you how much of the loss is mixed.
Quiz: Understanding Audiograms
• If a hearing threshold were at 0 dB HL by air conduction,
and 0 dB HL by bone conduction, what type of loss exists?
• If a hearing threshold were 50 dB HL by air conduction,
and 5 dB HL by bone conduction, what type of loss exists?
Quiz: Understanding Audiograms
• If a hearing threshold were 50 dB HL by air conduction,
and 30 dB HL by bone conduction, what type of loss exists?
• If a hearing threshold was 50 dB HL by air conduction,
and 55 dB HL by bone conduction, what type of loss exists?
• How can you have bone conduction be worse than air
conduction?
Basic Audiograms
What are the audiometric symbols that are used for hearing
testing (assuming that we are not masking the non-test ear)?
Question: Basic Audiograms
• How are these symbols
placed relative to one of
the frequency lines?
• Can you envision where
you would place these
symbols if both air and
bone conduction
thresholds are at 0 dB HL
for the right ear, and 15 dB
HL for the left ear at 1KHz?
Question: Basic Audiograms
What are common ways of remembering where the symbols go,
what colors are used, etc.?
Basic Audiograms
Question: Basic Audiograms
• Describe this
audiogram.
• What ear was
tested?
Question: Basic Audiograms
• Describe this
audiogram.
• What ear was
tested?
Question: Basic Audiograms
• Describe this
audiogram.
• What ear was
tested?
Question: Basic Audiograms
• Describe this
audiogram.
• What ear was
tested?
Question: Basic Audiograms
• Describe this
audiogram.
• What ear was
tested?
Complete the Table: Basic Audiograms
Conductive
Air conduction
thresholds
(normal or loss)
Bone conduction
thresholds
(normal or loss)
Air-bone gap
(significant or not)
Location of the
problem
(part of ear)
Sensorineural
Mixed