Audiology - Screening Flashcards Preview

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Flashcards in Audiology - Screening Deck (41)
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1
Q

When did neonatal screening for UK babies begin?

A

2003

2
Q

What was the norm before neonatal screening for UK babies?

A

Only at risk populations were targeted

3
Q

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

A

30 - 40%

4
Q

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

A

Otoacoustic Emissions Test (OAE)

5
Q

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

A

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

6
Q

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

A

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

7
Q

What are Otoacoustic Emissions?

A

Weak signals that reflect off the outer hair cells

8
Q

How do Otoacoustic Emission Tests work?

A

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

9
Q

How do Otoacoustic Emission signals arrive in the ear canal?

A

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

10
Q

How are Otoacoustic Emissions measured?

A

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

11
Q

What do healthy cochleae produce?

A

A highly reproducible spectral pattern unique to each ear

12
Q

Are Otoacoustic Emission Tests dependent on the client being conscious?

A

No - babies can be tested while asleep

13
Q

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

A

It will have several peaks and troughs

14
Q

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

A

Refer for diagnostic testing

15
Q

What can obscure test results?

A

Background noise and middle ear problems (glue ear etc)

16
Q

What cannot be detected by Otoacoustic Emissions?

A

Pathologies beyond the cochlea

17
Q

What does AABR stand for?

A

Automated Auditory Brainstem Response

18
Q

What type of test is AABR?

A

Objective

19
Q

What does AABR record?

A

The response of the brain in response to sounds

20
Q

What components does the auditory pathway contain?

A

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

21
Q

What is measured in AABR?

A

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

22
Q

What are Auditory Evoked Potentials often measured in response to?

A

Broad band clicks or tone bursts

23
Q

What processes are involved in Automated Brainstem Response testing?

A

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

24
Q

How are AEPs measured?

A

Differential signals across pairs of electrodes

25
Q

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

A

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

26
Q

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

A

Brainstem, midbrain, cortex

27
Q

How are AEPs described?

A

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

28
Q

What is meant by an early response to an AEP?

A

When a response occurs 0 to 10ms after stimulation

29
Q

Where do early responses originate from?

A

The cochlea, the auditory nerve and the brainstem

30
Q

What is meant by a middle response to an AEP?

A

When a response occurs 10 to 60ms after stimulation

31
Q

What is meant by a late response to an AEP?

A

When a response occurs 60 to 500ms after stimulation

32
Q

How long after birth should a child be AABR tested?

A

12 - 18 hours and retested 24 hours later if failed

33
Q

What are the stimuli for AABR tests?

A

Clicks or tone bursts in decreasing intensity steps

34
Q

At what intervals do the stimuli for AABR tests occur?

A

20 to 40 times a second

35
Q

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

A

Peaks I, III and V

36
Q

What does a clear response at 20 dBHL indicate?

A

Normal hearing

37
Q

What is Behaviour Observation Audiometry?

A

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

38
Q

Name a behavioural technique for screening young babies

A

Health Visitor Distraction Test

39
Q

What does the Health Visitor Distraction Test involve?

A

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

40
Q

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

A

Head turns, eye turns, stilling, increased activity

41
Q

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

A

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