Exam 3

Question 1

At which frequency levels do we conduct stapedial reflex threshold testing?

Answer 1

250, 500, & 1,000 Hz

Question 2

Stapedial reflex threshold definition & values

Answer 2

Lowest dB level at which we see the muscle contract. Normally present at 65 to 70 dB above A/C threshold.

Question 3

Stapedial reflex threshold is ______ in conductive hearing loss patients.

Answer 3

absent

Question 4

Stapedial reflex threshold is _____ than normal in patients w/ cochlear lesions & _____ than normal in patients w/ neural lesions.

Answer 4

Cochlear: lower than normal (65-70 dB above threshold)

Question 5

Stapedial reflex decay is significant in patients with ______ lesions

Answer 5

neural

Question 6

Recruitment vs. Decruitment

Answer 6

Recruitment: more sensitive to loudness; cochlear lesion
Decruitment: less sensitive to loudness; neural lesion

Question 7

At what level does the reflex pathway cross over?

Answer 7

Superior olivary complex

Question 8

Stapedial reflex decay procedure

Answer 8

Test at 10 dB above stapedial reflex threshold, hold for 10 seconds. Significant if amplitude is reduced by 50% or greater during the first 5 seconds of stimulation (nerve becomes fatigued)

Question 9

Where are the electrodes for ABR placed?

Answer 9

3 electrodes: one on top of head, one behind each ear

Question 10

ABR provides information about hearing status between which frequencies?

Answer 10

1,000-4,000 Hz

Question 11

Where do each of the 5 ABR waves come from?

Answer 11

I and II: auditory nerve
III: cochlear nucleus
IV: SOC
V: lateral lemniscus

Question 12

Which wave tells us about the degree of loss?

Answer 12

V

Question 13

Absolute latency for ABR

Answer 13

Wave I: 2 ms
Wave III: 4 ms
Wave V: 6 ms

Question 14

Relative/interpeak latency for ABR

Answer 14

Between I to III and III to V: 2 ms

Between I to V: 4 ms

Question 15

ABR profile for cochlear lesion or conductive hearing loss

Answer 15

Absolute latencies are prolonged/abnormal

Interpeak latencies are normal

Question 16

ABR profile for neural lesion

Answer 16

Absolute latencies are prolonged/abnormal

Interpeak latencies are abnormal

Question 17

OAEs test the function of what?

Answer 17

The outer hair cells

Question 18

Why is OAE testing done at low intensities (38-40 dB)?

Answer 18

OHCs work primarily @ lower intensities (the stereocilia make contact w/ the tectorial membrane)

Question 19

TEOAEs

Answer 19

Transient Evoked. Clicks or tonebursts at 1,000-4,000 Hz

Question 20

DPOAEs

Answer 20

Distortion Product. Pairs of puretones. Give more reliable/valid results in noise (e.g., NICU).

Question 21

What outer ear pathologies might cause conductive hearing loss?

Answer 21

Absence of pinna, closure of EAM, otitis externa, foreign objects in EAM

Question 22

Otitis media w/ effusion

Answer 22

Fluid persists because of bacterial infection (acute cases are usually viral). Chronic if lasting for 4 months of longer.

Question 23

What are some possible causes of OME?

Answer 23

Eustachian tube dysfunction, suppressed immune system, head-neck abnormalities, passive smoking, group day care attendance, socio-economic factors, & genetics.

Question 24

Why are kids <5 more susceptible to OME?

Answer 24

Their eustachian tubes are shorter & straighter.

Question 25

Why is passive smoking a risk factor for OME?

Answer 25

It causes vasoconstriction and increases blood viscosity, which deceases blood flow to the inner ear.

Question 26

Tympanocentesis

Answer 26

Sampling the middle ear fluid to determine bacterial cause of infection

Question 27

Myringotomy

Answer 27

ENT drains the fluid from the middle ear

Question 28

PE tubes

Answer 28

Pressure equalization. Tiny valve placed in TM to help with eustachian tube dysfunction

Question 29

What will the tympanogram of someone who has OME look like?

Answer 29

Type B (flat)

Question 30

What will the tympanogram of someone who has otosclerosis look like?

Answer 30

Shallower than normal (type AS)

Question 31

What will the tympanogram of someone who has eustachian tube dysfunction look like?

Answer 31

Type C - negative middle ear pressure, peak @ <-100

Question 32

What causes otosclerosis?

Answer 32

Calcification of the stapes bone fixes it to the oval window

Question 33

What will the audiometric profile of someone w/ otosclerosis look like?

Answer 33

Bilateral conductive HL w/ poorer B/C thresholds @ 2,000 Hz (AKA Carhart notch)

Question 34

OAEs will be ______ in patients w/ conductive HL

Answer 34

absent