Audiology - Screening

Question 1

When did neonatal screening for UK babies begin?

Answer 1

2003

Question 2

What was the norm before neonatal screening for UK babies?

Answer 2

Only at risk populations were targeted

Question 3

What % of hearing impaired babies have no known risk factors?

Answer 3

30 - 40%

Question 4

What is the main screening technique used for babies in the UK?

Answer 4

Otoacoustic Emissions Test (OAE)

Question 5

What type of permanent hearing loss is usually seen at birth?

Answer 5

Sensori-neural (the cochlea is fully formed at birth)

Question 6

What are some of the features of the Otoacoustic Emissions Test?

Answer 6

High sensitivity and specificity, non-invasive, objective, cost-effective

Question 7

What are Otoacoustic Emissions?

Answer 7

Weak signals that reflect off the outer hair cells

Question 8

How do Otoacoustic Emission Tests work?

Answer 8

The cochlea is stimulated by the incoming sound, there is incomplete energy absorption and the weak outer hair cell activity is recorded as sound in the ear canal

Question 9

How do Otoacoustic Emission signals arrive in the ear canal?

Answer 9

Cochlea stimulated - Basal Membrane disturbances travel away from sensory cells to the basal end of the cochlea - middle ear structures start to vibrate - sound wave created in outer ear canal

Question 10

How are Otoacoustic Emissions measured?

Answer 10

Using a sensitive microphone (portable probe) which is inserted in to the ear

Question 11

What do healthy cochleae produce?

Answer 11

A highly reproducible spectral pattern unique to each ear

Question 12

Are Otoacoustic Emission Tests dependent on the client being conscious?

Answer 12

No - babies can be tested while asleep

Question 13

If the cochlea responds to the Otoacoustic Emissions, what will the graph look like?

Answer 13

It will have several peaks and troughs

Question 14

If there is no response from the cochlea during testing, what is the next step?

Answer 14

Refer for diagnostic testing

Question 15

What can obscure test results?

Answer 15

Background noise and middle ear problems (glue ear etc)

Question 16

What cannot be detected by Otoacoustic Emissions?

Answer 16

Pathologies beyond the cochlea

Question 17

What does AABR stand for?

Answer 17

Automated Auditory Brainstem Response

Question 18

What type of test is AABR?

Answer 18

Objective

Question 19

What does AABR record?

Answer 19

The response of the brain in response to sounds

Question 20

What components does the auditory pathway contain?

Answer 20

The cochlea, the VIII nerve, the brainstem, the midbrain and the cortex

Question 21

What is measured in AABR?

Answer 21

Auditory Evoked Potentials (electrical charges produced in the auditory neural pathway)

Question 22

What are Auditory Evoked Potentials often measured in response to?

Answer 22

Broad band clicks or tone bursts

Question 23

What processes are involved in Automated Brainstem Response testing?

Answer 23

Audiometer generates stimuli, scalp electrodes detect tiny electrical signals, picked up by a monitor and recorded

Question 24

How are AEPs measured?

Answer 24

Differential signals across pairs of electrodes

Question 25

What are the names of the two electrodes used in AABR testing?

Answer 25

Active (positioned over area of high response activity) and Reference (positioned over area of low response activity)

Question 26

What 3 areas of the auditory pathway are AEPs measured from?

Answer 26

Brainstem, midbrain, cortex

Question 27

How are AEPs described?

Answer 27

In terms of their latency (time of response following stimuli)

Question 28

What is meant by an early response to an AEP?

Answer 28

When a response occurs 0 to 10ms after stimulation

Question 29

Where do early responses originate from?

Answer 29

The cochlea, the auditory nerve and the brainstem

Question 30

What is meant by a middle response to an AEP?

Answer 30

When a response occurs 10 to 60ms after stimulation

Question 31

What is meant by a late response to an AEP?

Answer 31

When a response occurs 60 to 500ms after stimulation

Question 32

How long after birth should a child be AABR tested?

Answer 32

12 - 18 hours and retested 24 hours later if failed

Question 33

What are the stimuli for AABR tests?

Answer 33

Clicks or tone bursts in decreasing intensity steps

Question 34

At what intervals do the stimuli for AABR tests occur?

Answer 34

20 to 40 times a second

Question 35

What are the most important peaks in response to AABR tests?

Answer 35

Peaks I, III and V

Question 36

What does a clear response at 20 dBHL indicate?

Answer 36

Normal hearing

Question 37

What is Behaviour Observation Audiometry?

Answer 37

Checklist for parents re newborns behaviour (responses to sounds etc)

Question 38

Name a behavioural technique for screening young babies

Answer 38

Health Visitor Distraction Test

Question 39

What does the Health Visitor Distraction Test involve?

Answer 39

Recording child’s responses to certain stimuli (rattle, ss, humming)

Question 40

What kind of responses are health visitors looking for in the Health Visitor Distraction Test?

Answer 40

Head turns, eye turns, stilling, increased activity

Question 41

What are some of the possible problems with the Health Visitors Distraction Test?

Answer 41

Not following procedures, visual or tactile cueing, rhythmic presentation of stimuli