Immittance Part II - Acoustic Stapedial Reflex

Question 1

What are acoustic reflexes?

Answer 1

Bilateral response to an activating stimulus; both stapedius muscles contract

Question 2

What are acoustic reflex thresholds?

Answer 2

Lowest intensity that gets an acoustic reflex response from a stimulus for each ear

Question 3

Acoustic reflex decay assesses the function of ________________.

Answer 3

auditory and facial nerves

Question 4

What is the difference between the stimulus effect and probe effect?

Question 5

Describe an interaxial lesion

Question 6

How do you predict hearing sensitivity from acoustis reflexes?

Question 7

Acoustic reflexes is a ________________ phenomenon

Answer 7

Bilateral

Question 8

Stimulus is presented in the right ear.
Response is measured in the left ear.

Answer 8

Right contralateral

Question 9

Stimulus is presented in the left ear.
Response is measured in the left ear.

Answer 9

Left ipsilateral

Question 10

Stimulus is presented in the left ear.
Response is measured in the right ear.

Answer 10

Left contralateral

Question 11

Stimulus is presented in the right ear.
Response is measured in the right ear.

Answer 11

Right ipsilateral

Question 12

Describe the pathway for right contralateral reflex

Answer 12

1. Right middle ear
2. Right cochlea
3. Right CN VIII
4. Right ventral cochlear nucleus
5. Left superior olivary complex
6. Left facial motor nucleus
7. Left CN VII
8. Left middle ear

Question 13

T/F: Typically, the higher the intensity of the stimulus, the greater the reduction in middle ear admittance

Answer 13

False

Question 14

What are the (3) tests that can be run using an immittance meter (aka immittance bridge)?

Answer 14

1. Tympanometry
2. Acoustic reflex threshold
3. Acoustic reflex decay

Question 15

What is the function of the manometer?

Answer 15

Alters and measures pressure in the ear canal

Question 16

What is the function of the microphone?

Answer 16

Measures SPL of the probe tone; allows calculation of the admittance of the middle ear system

Question 17

What is the function of the reflex stimulus loudspeaker?

Answer 17

Generates high intensity stimuli

Question 18

What is the function of the probe tone loudspeaker?

Answer 18

Generates probe tone

Question 19

The probe tone frequency most typically used is ______________Hz. In infants, _______________ Hz probe tone should be used.

Answer 19

226 Hz
1000 Hz

Question 20

During tympanometry, admittance is first measured with the ear canal pressure at ________ daPa. At this pressure level, admittance is very ___________ because the T M and the middle ear system is rigid and much sound energy is reflected back

Answer 20

+200
low

Question 21

During tympanometry, pressure is swept through to __________ daPa, and changes in the admittance is recorded.

Answer 21

-400