Immittance Part II - Acoustic Stapedial Reflex Flashcards
What are acoustic reflexes?
Bilateral response to an activating stimulus; both stapedius muscles contract
What are acoustic reflex thresholds?
Lowest intensity that gets an acoustic reflex response from a stimulus for each ear
Acoustic reflex decay assesses the function of ________________.
auditory and facial nerves
What is the difference between the stimulus effect and probe effect?
Describe an interaxial lesion
How do you predict hearing sensitivity from acoustis reflexes?
Acoustic reflexes is a ________________ phenomenon
Bilateral
Stimulus is presented in the right ear.
Response is measured in the left ear.
Right contralateral
Stimulus is presented in the left ear.
Response is measured in the left ear.
Left ipsilateral
Stimulus is presented in the left ear.
Response is measured in the right ear.
Left contralateral
Stimulus is presented in the right ear.
Response is measured in the right ear.
Right ipsilateral
Describe the pathway for right contralateral reflex
- Right middle ear
- Right cochlea
- Right CN VIII
- Right ventral cochlear nucleus
- Left superior olivary complex
- Left facial motor nucleus
- Left CN VII
- Left middle ear
T/F: Typically, the higher the intensity of the stimulus, the greater the reduction in middle ear admittance
False
What are the (3) tests that can be run using an immittance meter (aka immittance bridge)?
- Tympanometry
- Acoustic reflex threshold
- Acoustic reflex decay
What is the function of the manometer?
Alters and measures pressure in the ear canal
What is the function of the microphone?
Measures SPL of the probe tone; allows calculation of the admittance of the middle ear system
What is the function of the reflex stimulus loudspeaker?
Generates high intensity stimuli
What is the function of the probe tone loudspeaker?
Generates probe tone
The probe tone frequency most typically used is ______________Hz. In infants, _______________ Hz probe tone should be used.
226 Hz
1000 Hz
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
+200
low
During tympanometry, pressure is swept through to __________ daPa, and changes in the admittance is recorded.
-400
