OAE Review

Question 1

What do outer hair cells do?

Answer 1

They amplify movement of the basilar membrane during low-intensity sound stimuli

Question 2

How do OHCs function?

Answer 2

They change their lengths in response to stimuli (electromotility)

Question 3

When there is a greater change in length of the OHCs, what does that mean?

Answer 3

There is more stereocilia bending, more transduction and greater response

Question 4

How much do OHCs improve our hearing sensitivity?

Answer 4

40 dB improvement

Question 5

How much hearing loss do damages OHCs produce?

Answer 5

mild to moderate SNHL

Question 6

Do OHCs sharpen the tonotopic organization of the basilar membrane?

Answer 6

Yes

Question 7

What do IHCs do?

Answer 7

They serve as the actual sensory receptors of hearing
Transform sound vibrations present in cochlear fluids into electrical signals that can then travel the auditory nerve to the brainstem and auditory cortex

Question 8

What type of hearing loss does IHC damage result in?

Answer 8

Severe to profound SNHL

Question 9

What are OAEs?

Answer 9

The cochlea emitting sound

Question 10

What are the different types of OAEs?

Answer 10

Spontaneous OAEs
Transient evoked OAEs
Distortion Product OAEs
Stimulus Frequency OAEs

Question 11

What are spontaneous OAEs?

Answer 11

They are emissions that are not evoked
They occur naturally
They only occur in normal cochleas
Only occur in about 60% of normal ears

Question 12

Are a majority of people unaware of spontaneous OAEs?

Answer 12

Yes
However, some perceive it as annoying tinnitus

Question 13

Are spontaneous OAEs clinically useful?

Answer 13

No

Question 14

What are transient evoked OAEs?

Answer 14

Present in individuals with normal hearing
Click stimuli (broad band)
Broad band responses
500 to 4000 or 5000 Hz
Amplitude averages 10-12 dB SPL in young adults

Question 15

Why are clicks broad band?

Answer 15

They have spectral splatter

Question 16

Can TEOAEs be used to screen infant hearing?

Answer 16

Yes

Question 17

Can TEOAEs be used to validate thresholds?

Answer 17

Yes

Question 18

Can TEOAEs be used to assess cochlear function relative to the site of lesion?

Answer 18

Yes

Question 19

Is there frequency specificity for TEOAEs?

Answer 19

Limited
Response is broad

Question 20

What are distortion product OAEs?

Answer 20

2F1-F2 results in the best emissions in humans
Two pure tones are presented simultaneously

Question 21

What does 2F1-F2 tell us?

Answer 21

It gives us a 3rd frequency that is the one that comes out of the cochlea

Question 22

Is the presence of DPOAEs dependent on hearing sensitivity in the region of the primaries?

Answer 22

Yes

Question 23

Can DPOAEs be used to screen infant hearing?

Answer 23

Yes

Question 24

Can DPOAEs be used to validate behavioral thresholds?

Answer 24

Yes

Question 25

Can DPOAEs be used to assess cochlear function relative to site of lesion?

Answer 25

Yes

Question 26

Can DPOAEs be used for ototoxic monitoring?

Answer 26

Yes

Question 27

Do DPOAEs have greater frequency specificity?

Answer 27

Yes

Question 28

What are stimulus frequency OAEs?

Answer 28

Newer, less common Not clinically used Measuring the stimulus and the emission and picking up the difference between them

Question 29

Are OAEs used clinically to evaluate the health of the inner ear?

Answer 29

Yes

Question 30

What are some non-pathologic factors that can influence OAEs?

Answer 30

Age Gender Ear difference Diurnal effects (sleep-wake cycle) Genetics Race Body temp Body position State of arousal and attention Poor probe placement Ear canal acoustics/standing waves Debris, cerumen, foreign objects Uncooperative patient Noise

Question 31

How to minimize the effect of noise on OAEs?

Answer 31

A deep and secure probe fit An adequate number of stimulus repetitions Appropriate stopping criteria Emphasis on or exclusive presentation of signals at frequencies higher than 1 kHz A protocol that presents signals from higher to lower frequencies (DPOAE)