An introduction to pure tone audiometry and tympanometry

Question 1

Name the 2 ways we hear.

Answer 1

Air conduction

Bone conduction.

Question 2

Describe the pathway of air conduction.

Answer 2

Sound passes via the outer ear, middle ear and inner ear (cochlea).

Question 3

In bone conduction what does sound wave vibration stimulate?

Answer 3

It stimulates the cochlea directly.

Question 4

The auditory nerve is near the ___.

Answer 4

cochlea.

Question 5

What is a pure tone threshold?

Answer 5

the quietest sound you can hear.

Question 6

Assessment using pure tone thresholds is known as ….

Answer 6

Pure Tone Audiometry (PTA)

Question 7

What are pure tones characterised by?

Answer 7

They are characterised by frequency (pitch) and amplitude (volume).

Question 8

What does Pure-Tone Audiometry tell us?

Answer 8

• Provides information about the type of hearing loss (outer/middle ear problem or inner ear problem)
• Quantifies frequency specific threshold elevation, giving us more detail about the nature of Hearing Loss.

Question 9

PTA is used to assess patient’s hearing acuity over a range of __________. What range do they need to ensure is covered?

Answer 9

Frequencies.

The speech banana range.

Question 10

Hz means what?

Answer 10

Waves per second.

Refers to frequency.

Question 11

PTA assesses hearing at different frequencies-
eg air conduction = 250-_______ Hz
bone conduction= _____- 4000 Hz

Answer 11

8000

500

Question 12

X on the audiogram means…

Answer 12

Left ear air conduction.

Question 13

O on the audiogram means…

Answer 13

Right ear air conduction.

Question 14

What sign is used on an audiogram to mark “not masked bone conduction”?

Answer 14

A triangle

Question 15

[

means ___________ ear _________ _______ on an audiogram.

Answer 15

Right ear masked BC (bone conduction)

Question 16

]

means ___________ ear _________ _______ on an audiogram.

Answer 16

Left ear masked BC (bone conduction)

Question 17

We measure hearing using dB HL because…

Answer 17

Its easier, it makes the numbers nicer.

Question 18

PTA is the single most….

Answer 18

sensitive initial measure that can identify pathology.

Question 19

PTA is used to give us ________ information (aka. the type of HL) and the ______ of HL.

Answer 19

Diagnostic

Degree

Question 20

PTA is a _______ measure.

Answer 20

Quantitative

Question 21

PTA is used for assessing candidacy for what?

Answer 21

Hearing aids and cochlear implants.

Question 22

_________ is crucial in fitting hearing aids.

Answer 22

PTA

Question 23

Name the types of hearing loss.

Answer 23

Sensory (inner ear)
Conductive (middle/outer ear)
Mixed (combination of both)

Question 24

The bone conductor headband rests behind the ______ _______________.

Answer 24

mastoid process.

Question 25

What do Air Conduction thresholds assess?

Answer 25

They assess the entire auditory pathway- outer, middle and inner.

Question 26

What is used to assess air conduction?

Answer 26

Headphones/earphones

Question 27

What do Bone Conduction thresholds assess?

Answer 27

The inner ear.

Question 28

What is used to assess Bone conduction?

Answer 28

Bone conductor headset. (hairband)

Question 29

If AC and BC are equal, what can we assume?

Answer 29

Inner ear problems.

Question 30

If AC is worse than BC, what can we assume?

Answer 30

Outer/middle ear problem.

Question 31

The test room has to be relatively _____ ________.

Answer 31

sound proof.

Question 32

Tidiness, temperature and ambient noise levels should be controlled for a __________ ________.

Answer 32

test room.

Question 33

What must be followed when carrying out an audiometry test? Why?

Answer 33

``` Professional standards (specific rules) So results can be compared to norms, other clinics etc. ```

Question 34

What is used to check the dB HL presented to the client?

Answer 34

a Sound Meter.

Question 35

Make sure to ______ headphones between uses.

Answer 35

clean

Question 36

Clear and consistent __________ must be given to the client when about to perform the test.

Answer 36

instructions

Question 37

When performing PTA, what ear do they start with?

Answer 37

The better ear.

Question 38

Why does PTA procedure involve starting at 1000 Hz, and 30-40 dB above estimated threshold?

Answer 38

Allows patient to get comfortable.

Question 39

If there is no response, what procedure do we do?

Answer 39

1 down-1 up staircase procedure.

Question 40

Procedure: - test best ear - test _____ _____ - repeat for ______ ______ - assess need for _____.

Answer 40

Other ear Bone condction masking

Question 41

Name factors that could cause the threshold to be variable.

Answer 41

- Patient eg. tired - Equipment - Background noise - Procedural eg. instructions given.

Question 42

The reliabilitiy of the threshold must consider a 5-10dB error as well as ....

Answer 42

The skill of the tester | The patient exaggerating (compensation claims) aka. non-organic hearing loss.

Question 43

Name some limitations of PTA.

Answer 43

- Pure-tones while standard, not ecologically valid (not representative in real life) - Doesn't account for inner hair cell health, cognitive ability, higher auditory processes.

Question 44

Name a practical limitation of PTA.

Answer 44

Transcranial transmission (transmission of sound reaching contralateral ear) can lead to cross hearing.

Question 45

Explain the concept of interaural attenuation, if 60dB is presented to the right ear through AC.

Answer 45

20dB reaches the left ear (theres always a 40dB loss between ears).

Question 46

Interaural attenuation in bone conduction- what is the loss between the ears?

Answer 46

There is 0dB loss/ no loss :) | eg. 20 dB in L > 20 dB in R

Question 47

Why is cross hearing a problem?

Answer 47

When testing the worse ear, the better ear (non-test ear) might detect the signal and patient may respond that they heard a noise- but this wouldn't be a reflection of the worse ear's ability.

Question 48

When the difference in thresholds of the two ears is greater than the interaural attenuation of the signal, what may occur?

Answer 48

Cross hearing may occur.

Question 49

In cross hearing, the apparent threshold of the worse ear may be a ....

Answer 49

"shadow" of the better ear.

Question 50

What do we need to avoid to confirm true thresholds?

Answer 50

We need to avoid false ear-specific thresholds aka. cross hearing.

Question 51

What is the solution to stop cross hearing?

Answer 51

Masking.

Question 52

What is masking?

Answer 52

A narrow band level noise is played in the non-test ear, so it makes the test tone inaudible to the non-test ear.

Question 53

Masking removes the possibility of _____ ________.

Answer 53

Cross Hearing.

Question 54

What does masking allow?

Answer 54

It allows us to isolate and test the test ear without cross hearing.

Question 55

When is bone conduction masking required?

Answer 55

When the non-masked BC is better than the unmasked AC threshold by 10 dB or more. This is called an air-bone gap).

Question 56

_______________= masked pure tone threshold

Answer 56

plateau

Question 57

When is AC masking required?

Answer 57

Where the difference between unmasked L and R AC thresholds id 40 dB or more.

Question 58

Interaural attenuation is _____ dB with ________ headphones.

Answer 58

40 | circumaural.

Question 59

________ _____________ results in a false picture of a patients's hearing status.

Answer 59

Cross Hearing.

Question 60

Name- | The minimum intensity level which is judged to be uncomfortably loud to the patient when applied monaurally is measured.

Answer 60

Uncomfortable Loudness Levels.

Question 61

What is uncomfortable loudness levels used for?

Answer 61

- Used for fitting hearing aids, setting maximum output levels (so hearing aid doesn't over amplify this level) - used in diagnosis of hyperacusis (over sensitivity to everyday sound).

Question 62

Procedure for Uncomfortable Loudness Level- - __ ____ presented - Increase intensity in ___ dB steps until patient indicates the sound is ____________.

Answer 62

Pure Tones 5dB Uncomfortable.

Question 63

How is hearing tested in Infants (1-2 years old)?

Answer 63

Operant conditioning based test: -visual reinforcement audiology; the tester distracts the child, sound presented at side of child, if the child turns to side- they can hear the sound. For clear head turn response they get a visually appealing reward.

Question 64

How is hearing tested in Children (2-5 years old)?

Answer 64

Classical conditioning based test: -conditioned play audiometry; tester teaches child to put person in boat only when they hear a noise Socially reinforced with smiles and praise.

Question 65

What must a test be for a child?

Answer 65

stimulating and rewarding.

Question 66

Name some reasons why testing children is challenging?

Answer 66

- some children may not cooperate - every child is different - chronological age doesn't determine developmental age, child may find it hard to focus.

Question 67

What does tympanometry measure?

Answer 67

Compliance (stiffness) of the middle ear, as a function of pressure.

Question 68

As well as middle ear compliance, what else does tympanometry measure?

Answer 68

Also measures ear canal volume.

Question 69

What is tympanometry not a test of?

Answer 69

It's not a test of hearing acuity.

Question 70

Who is tympanometry suitable for?

Answer 70

Both adults and paediatrics.

Question 71

Tympanometry measurement: - probe tone generated and strikes the _______ which then vibrates the _____ ear - The ________ ______ is measured - Probe seal allows air pump to measure _________.

Answer 71

Tympanic membrane Middle reflected sound pressure.

Question 72

What does a normal tympanogram look like?

Answer 72

A nice peak :)

Question 73

Why are colds and otitis media with effusion more common in children?

Answer 73

Their Eustachian tubes are not fully developed eg. poorer at ventilation, so more likely to get things like glue ear.

Question 74

Name the characteristics that would show developing otitis media with effusion.

Answer 74

- Blocked Eustachian Tube - Retracted Tympanic Membrane - high negative pressure (peak more to left) on tympanogram.

Question 75

If there is middle ear fluid, what will the tympanogram look like?

Answer 75

straight line (near bottom).

Question 76

If there is a straight line near the top of the tympanogram, what would this suggest?

Answer 76

Tympanic Membrane Perforation

Question 77

A small peak on the tympanogram would suggest...

Answer 77

Ostosclerosis.

Question 78

What is ostosclerosis?

Answer 78

Genetic condition where the ossicles don't move well aka. they are fixated.

Question 79

If the peak was too big on the tympanogram, what would this show?

Answer 79

Ossicular chain discontinuity.

Question 80

what is- Ossicular chain discontinuity?

Answer 80

Dislocation of ossicles, so they move too much- this means compliance is through the roof (too much movement).