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Conduct hearing assessments
Contents
Key to resources
2
Introduction
4
Identify significant features of client history
4
Select appropriate hearing assessment/s and explain
procedure to client
5
Conduct assessments – pure tone audiometry
5
Identifying the need for further testing
7
Recording reliable results
8
Impedance audiometry
10
Tympanometry
10
Acoustic reflexes
12
Acoustic reflex decay
13
Use results to identify specific hearing loss and/or any
abnormal functions
14
Summary
15
Further reading
16
Conduct hearing assessments
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This task guide is based on the following resources:

Martin FN and Clark JG (2006) Introduction to Audiology (9th edn), Allyn and
Bacon, USA*

3064-3 – Psychoacoustics

3064-9 – Audiometry-Assessment A

3064-10 – Audiometry-Assessment B

3064-2 – HLSP Audiometry – Pathologies (useful to review for this unit)
*Note: The page number references provided for the textbook are based on the 9 th edition.
If you have an earlier or later edition of the textbook, these pages numbers may not be the
same ( but may be approximate). The headings are likely to be the same or similar in the
various editions.
The abovementioned resources – except for the textbook – are available in the Your
Resources section.
Key to resources
Resource
number
Resource title
1
3064-3 Psychoacoustics
2
Martin FN and Clark JG (2006) Introduction to Audiology (9th edn), Allyn
and Bacon, USA
Chapter 2 The Human ear and simple tests of hearing
Chapter 3 Sound and its measurement
3
Audiometry-Assessment A 3064-9
Pages 5-24
4
Martin FN and Clark JG (2006) Introduction to Audiology (9th edn), Allyn
and Bacon, USA
Chapter 4 Pure-tone Audiometry
5
Audiometry-Assessment B 3064-10
Topic 1 Identifying the need for further testing
Topic 2 Post-basic assessment - Masking
6
Martin FN and Clark JG (2006) Introduction to Audiology (9th edn), Allyn
and Bacon, USA
Chapter 12 Nonorganic hearing loss
2
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Martin FN and Clark JG (2006) Introduction to Audiology (9th edn), Allyn
and Bacon, USA
Chapter 6 Diagnostic hearing tests. Read pages 149-154 on Acoustic
Immitance
8
Audiometry-Assessment B 3064-10
Topic 4 Tympanometry
9
Before you work through the readings below, you may wish to review the
resource 3064-2-HLSP Audiometry – Pathologies (available in the Your
Resources section).
Martin FN and Clark JG (2006) Introduction to Audiology (9th edn), Allyn
and Bacon, USA
Chapter 8 The Outer Ear
Chapter 9 The Middle Ear
Chapter 10 The Inner Ear
Chapter 11 The Auditory Nerve and Central Auditory Pathways
10
Martin FN and Clark JG (2006) Introduction to Audiology (9th edn), Allyn
and Bacon, USA
Chapter 6 Acoustic Reflexes
11
Martin FN and Clark JG (2006) Introduction to Audiology (9th edn), Allyn
and Bacon, USA
Chapter 6 Acoustic Reflex Decay
12
Audiometry-Assessment A 3064-9
Pages 25-31, examples of audiograms with their descriptions
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Introduction
In this task guide you will learn about conducting hearing tests.
Specifically, you will learn to:

identify significant features of client history

select appropriate hearing assessment/s and explain procedure to
client

wear appropriate personal protection clothing correctly and follow
infection control procedures

conduct assessments to produce valid, reliable and accurate results
and in accordance with relevant policy and procedures

use results to identify specific hearing loss and/or any abnormal
functions

record results in accordance with relevant policy and procedures.
Identify significant features of client
history
Once you have taken a client history, you can establish a number of things:

Is there anything of significance in the history that requires you to
refer the client?

Do you need to alter your usual basic test battery?

Are there any additional tests you should carry out?

The history should also give you a hint as to what you may expect to
see.

If your results are significantly different from what you expect from
the case history, why is this?
Now reflect on the questions below:
What do you believe to be significant features of the client history that are
able to give you the information you are looking for in the list above?
Are the features purely medical, or do they involve personal, social and legal
issues as well?
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Select appropriate hearing
assessment/s and explain procedure to
client
You now need to make a decision as to what type of assessment you are
going to perform. The case history, in most cases, will tell you whether you
are doing a screening test or a full hearing assessment. If the client is a
child, you will need to use an age-appropriate assessment technique such as
Play audiometry.
What is the basic test battery in your clinic? Why would you veer from the
usual tests? What extra tests might be done, or referred for?
Conduct assessments – pure tone
audiometry
Conducting the hearing assessments is the bulk of your appointment, and the
very reason most people are seeing you. You need to be able to select the
appropriate tests, perform them in a valid manner and record results
accurately.
Before we launch into hearing tests, work through the following resource, if
you have not done so previously.
Go to Resource 1
Go to 3064-3 Psychoaccoustics.
Go to Resource 2
Go to Introduction to Audiology, Chapters 2 and 3.
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You should now have an understanding of the concepts surrounding sound,
the decibel and how sound is conducted along the hearing pathway.
Check that you have a sound understanding of the following concepts:
I am now familiar with this…
anatomy of the ear
Weber test
sine waves
longitudinal waves
frequency
spectrum
intensity
decibel
sound pressure level
hearing level
sensation level
pitch
loudness
localisation
masking
If you do not have a good understanding of any of the above concepts,
revise your textbook.
Now go to Resource 3
Go to Audiometry – Assessment A 3064-9 and work through pages 5–24 in
this resource.
Now go to Resource 4
Go to Chapter 4 in Introduction to Audiology.
Also take a look at the CD-ROM that accompanies the textbook — look at
the hearing test instructions in the Professional section.
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You should also observe your supervisor doing hearing assessments, and
when you are ready, start doing assessments on the people in your office and
willing friends and family. When you and your supervisor are comfortable,
that you are able to, start testing clients with your supervisor in the room
and summarise each appointment in your log book.
You should now be familiar with the following concepts:
I am now familiar with this…
audiometer
pure tone
narrow band masking noise
headphones
insert phones
bone conductor
interaural attenuation
cross-heard signal
masking
air-bone gap
sensorineural hearing loss
conductive hearing loss
mixed hearing loss
sound proof environment
tactile responses
Hughson-Westlake technique
patient response
Identifying the need for further testing
Now go to Resource 5
Go to Audiometry - Assessment B 3064-10, Topics 1 and 2.
Once you have obtained the pure tone thresholds for AC and BC, you need
to be able to look at your results and make a decision where further testing
is necessary. In this context, it means whether you need to use masking to
verify the pure tone thresholds you have recorded. Masking needs to be
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employed at any frequency where you are not sure from which ear (ie,
cochlea) your recorded result stemmed.
Think back to the concepts of interaural attenuation and any resultant crossheard signal. If there is a chance that the signal was heard by the non-test
cochlea, then we need to keep this ear busy to ensure that the final recorded
threshold is that of the test cochlea only. We do this by applying a noise to
the non-test ear. This is what masking is all about.
You will need to practice masking in your clinic time.
Remember: air conduction masking is required if there is a 40dB (or greater)
air-bone gap at any frequency.
Once you are comfortable with the concept of masking and the techniques
involved, start practising in the clinic and record your sessions in your
logbook.
Recording reliable results
Sometimes the results we get may not be reliable. This may be due to a
number of reasons:

client didn’t understand the test procedure

equipment failure

client disability

language barrier

client was not co-operative.
Client didn’t understand
In the first instant, the client should be re-instructed to ensure they
understand test procedure correctly.
Equipment failure
Equipment should have been tested at the start of the day. However
equipment can become faulty during the day’s testing. Sometimes it is
simple human error. The headphones may be on back to front, a switch on
the audiometer may be in the wrong position or a cable has become
unplugged. Check everything again.
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Client disability
The client may have a physical or mental disability. Age, either very young
or very old, can impact on a client’s ability to understand what is required of
them. You may need to repeat instructions using language appropriate to the
mental age of the client. You can also change the way they respond, if a
button is too difficult. Simply saying ‘yes’, tapping on the table, or raising
their hand when they hear a sound can make all the difference.
Language barrier
If the client does not have a good grasp of English, they may have difficulty
understanding instructions. Using gestures can often work, but the best way
is to engage the services of an interpreter. For Australian citizens, there is a
government interpreting service available.
Client was not co-operative
If the client was not co-operative, there is usually a good explanation. This
is called non-organic hearing loss.
The most common reason for people pretending to have a hearing loss is
when they are children looking for attention or as adults when there is
financial gain involved. This is generally the case if the client is seeking
compensation for hearing loss incurred at the work place. In most cases, reinstruction, time out or a change of tester will get a reliable result.
Remember never to accuse a client of faking results. You must always give
them the opportunity to ‘save face’, and in most cases they’ll come around.
If you are not able to elicit a reliable result, or results of audiometry, speech
hearing tests and reflex thresholds are inconsistent, write ‘not for
compensation purposes’ on the audiogram. This will alert all to the fact that
the test was not a reliable one.
Now go to Resource 6
Go to Introduction to Audiology and read Chapter 12 on non-organic
hearing loss. Think about the study questions on page 362. Then reflect on
the question below.
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Discuss with your supervisor what he or she does when they come across
non-organic hearing loss.
What are some of the tests you can do yourself, and what other tests can be
performed by Audiologists to get a reliable result?
Impedance audiometry
‘Impedance audiometry’ is a term that describes a number of tests which use
a sound probe and pressure gauge to determine the health and functionality
of the middle ear and the functionality of the contra and ipsilateral nerve
pathways by using reflex arcs. This gives us valuable information about the
health and functionality of the middle ear system, as well as the integrity or
lack thereof, of the neural pathways that connect the ears. Impedance
Audiometry should not be used in isolation and serves as a cross-reference
to pure tone audiometry.
For a great summary on these tests, go to the following website.
www.emedicine.com/ent/topic374.htm
Go to Resource 7
In Introduction to Audiology, read about acoustic immitance, pages 149–
154.
Tympanometry
Tympanometry is a test that gives us information about the functionality of
the middle ear.
Go to Resource 8
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Conduct hearing assessments
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Read Topic 4 in Assessment B 3064-10.
You should be familiar with the following concepts:
I am familiar with…
Compliance
middle ear pressure
volume
Jerger types
normal ranges
To supplement and extend your reading, go to the resource below.
Go to Resource 9
Read Chapters 8 to 11 in Introduction to Audiology. However, before
proceeding to this resource, you may want to review the resource 3064-2HLSP Audiometry–Pathologies (available in the Your Resources section).
Check if you are confident describing the major signs, symptoms and
hearing loss patterns for the following pathologies.
I am familiar with…
otitis externa
otitis media
otosclerosis
Meniere’s disease
acoustic neuroma
Activity
Start practising tympanometry in your clinic. It should be part of your standard test battery.
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A CD-ROM accompanies your Introduction to Audiology.textbook. Look at the case
studies section on this CD-ROM and see if you can readily identify the different types of
tympanograms.
Can you tell from them and the audiogram what pathology the client’s test results are
consistent with and what referral path should be followed?
_________________________________________________________________________
_________________________________________________________________________
_________________________________________________________________________
_________________________________________________________________________
_________________________________________________________________________
Logbook
Start doing tympanometry testing on clients as a matter of routine and
record your experiences in your logbook.
Acoustic reflexes
Acoustic reflexes are part of the impedance battery of tests.
Go to Resource 10
Go to Chapter 6 in Introduction to Audiology and read the section on
measuring the acoustic reflex on pages 159–164.
In order to understand the anatomy and physiology involved, go to the
Macquarie University, Department of Linguistics website:
www.ling.mq.edu.au/ling/units/index.html
Go to ‘Courses of study’ then ‘Undergraduate degrees’ then ‘Undergraduate
units’ then click on the unit website and choose ‘SPH307 Auditory
Physiology and Psychoacoustics’. Click on ‘Lectures’ on the top horizontal
menu.
Read these topics:
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
Outer and middle ear anatomy

The cochlea

Neural function and the auditory nerve

Auditory cortex and central auditory processing.
Note: Each section has a slide show available as well as notes and
further text references.
Acoustic reflex decay
Acoustic reflex decay is a test performed after the reflex threshold test as a
10dB sensation level is required. This test is only done contralaterally and
only at 500Hz and 1000Hz. Reflex decay indicates an 8th nerve lesion.
Go to Resource 11
Go to Chapter 6 in Introduction to Audiology and read the section on
acoustic reflex decay on pages 164–165.
The presence of acoustic reflex decay is a good indicator for referring
clients for further testing to exclude retro-cochlear pathology.
Eustachian tube function test
The Eustachian tube function test is also one of the Impedance tests, but is
generally only used in specific circumstances such as in Diver and Pilot
assessments. The ETF test is designed to determine whether the client is
able to equalize pressure in the middle ear. This is particularly important for
people wishing to dive as serious injury to the ear (barotrauma) is likely if
the diver is unable to do this at will.
Here is what the test involves the following:

The impedance probe is inserted into the ear canal and a good seal
established.

Pressure is reduced to -200 mmH2O.
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
Ask the client to swallow or yawn several times.

Run a full sweep, the peak compliance should now be negative.

Ask the client to perform a Valsalva manoeuver by pinching the
nostrils and blowing up their cheeks, forcing air up the Eustachian
tube and the middle ear pressure to equalize.

Run another sweep, the peak compliance should now have returned
to normal or positive.
Clients wishing to do a diving certificate, who are unable to perform a
Valsalva manoeuvre should not proceed as serious damage may be caused
to their ears and or balance system as a result of barotrauma.
Note: the ETF test requires an impedance meter which allows manual
control over the pressure pump.
Perilymph fistula
A perilymph fistula is a tiny hole, usually around the area of the round
window, which leaks perilymph fluid. This can make the client very dizzy,
especially when there is a change in pressure. This might happen when they
sneeze or blow their nose. Perilymph fistula can occur as a result of
barotraumas, trying to stop a sneeze or trauma to the head. By changing the
pressure in the ear canal it is possible to determine if a perilymph fistula is
present. This test is performed by audiologists and Ear Nose and Throat
surgeons.
Use results to identify specific hearing
loss and/or any abnormal functions
Once you have your test results, it is important for you to understand how to
interpret the results that you have.
Your interpretation will result in your ability to:
14

determine whether or not hearing loss is present

determine what type of hearing loss is present

cross-referencing whether or not results from different tests are
consistent with each other and with the case history

determine the need for further testing and/or referral to an
audiologist, medical practitioner or other third party

explain to the client the nature of the impairment and how it is likely
to affect them
Conduct hearing assessments
© NSW DET 2007

make recommendations to your client regarding the management of
the impairment.
Now reflect on the following:
List all the hearing tests you have learnt about and the normal and abnormal
results you may elicit.
Think about what each result means, what your referral path would be and
how you would write the report to convey your results clearly to your
referral.
Go to Resource 12
Read pages 25-31 of the resource Assessment A 3064-9.
Discuss with your supervisor the results that require referral to an
audiologist or medical practitioner.
The Rehabilitation Outcomes document of the Office of Hearing Services
also has information regarding the necessity to refer when certain conditions
are present, but these are also appropriate criteria for non-government
clients.
Rehabilitation Outcomes, Department of Health and Ageing:
www.health.gov.au/internet/wcms/publishing.nsf/Content/health-hearhroinfo
Summary
In this topic you have learnt about different pure tone audiometry, masking
and impedance audiometry. You have learnt how to perform the tests,
determine the need for further testing, the need for referral and the
interpretation of results.
Conduct hearing assessments
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Further reading
If you wish to carry out further research, here are some urls for you to
investigate.
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www.ebme.co.uk/arts/art9.htm
Overview of different audiometric
assessment techniques
www.ling.mq.edu.au/ling/units/index.html
For excellent resources in auditory
anatomy and physiology, linguistics and
psychoacoustics
www.ling.mq.edu.au/ling/units/sph307/papers
Click on the undergraduate units. The
following are of particular interest:

Ling 210 Phonetics and
phonology

SPH301 Acoustics and speech

SPH302 Speech physiology

SPH307 Auditory physiology and
psychoacoustics.
Conduct hearing assessments
© NSW DET 2007