Definitions
Acoustic Immitance: Overview
More Acoustic Immitance
Mostly Tymp
Mostly Acoustic Reflex
100
Opposition to the flow of energy
What is Impedance
100
Acoustic immitance helps identify abnormalities in these 5 areas related to the auditory system
What is 1. middle ear pathology 2. cochlear pathology 3. retrocochlear pathology 4. brainstem pathology 5. facial nerve disorder
100
True or false: Tympanometry permits a distinction between sensorinueural and conductive hearing loss.
What is: True
100
In Tympanometry -- the three values of interest are:
What is 1. peak pressure 2. static admittance 3. equivalent ear canal volume 4. shape of the function
100
What are the frequencies of the activator tones in acoustic reflex testing?
What is 500,1000,2000,4000Hz
200
East at which energy flows through a sytem
What is Admittance
200
What 3 measures are made at the plane of the TM?
What is 1. Static acoustic compliance 2. Tympanometry 3. Contraction of the middle ear muscles
200
______________ can be helpful in making the diagnosis of otitis media by demonstrating the presence of a middle ear effusion. Tympanometry or Acoustic Reflex
What is Tympanometry
200
What is the purpose of tympanometry?
What is Determine the point and magnitude of greatest compliance of the tympanic membrane
200
True or false: In acoustic reflex testing: When muscles contract, they pull on the TM and cause it to be stiffened during the reflex.
What is True
300
Impedance Z is made up of which two components?
What is 1. resistance and 2. reactance
300
What 3 instruments are found in the probe assembly in AI measures?
What is 1. loudspeaker 2. microphone 3. air pressure pump
300
To have a normal acoustic reflex, what 5 functions of the auditory pathway must be intact/normal?
What is middle ear function must be normal in each ear stapedius muscle must be intact auditory nerve must be normal facial nerve must be intact through the level of the branch to the stapedius muscle brainstem structures & functions must be intact through the level of the olivary nuclei
300
The ear drum is most mobile when?
What is when outer ear pressure matches middle ear pressure.
300
True or false: SPL in the canal decreases during the acoustic reflex
What is False
400
The middle ear system is largely __________ dominated (mass/stiffness)
What is stiffness dominated.
400
What is the most common probe tone frequency used in AI measures?
What is 226Hz
400
Tympanometry is performed by
What is Tympanometry loading the TM with air pressure equal to +200 dPA of, measuring it’s compliance and then making successive measurements of compliance as the pressure in the canal is decreased. Measuresments of SA compliance taken at +200dPa, 0daPA and -200daPa
400
In Tympanometry, normal static admittance values fall between:
What is .3 and 1.7mmhos
400
For normal listeners, the acoustic reflex is observed between
What is 85-100dBHL
500
Mass is an importance factor at ________ frequencies
What is high frequencies.
500
True or False: If the SPL picked up by the microphone is low, then the admittance is abnormally high and middle ear pathology is also likely
What is: True
500
The value of interest in Acoustic Reflex threshold testing is:
What is the ART -- acoustic reflex threshold
500
How is acoustic reflex is different from tympanometry?
What is 1. static air pressure is NOT varried
500
Possible acoustic reflex outcomes include:
What is The reflex is present at a normal level The reflex is absent at the limits of the equipment The reflex may be present, in the case of hearing loss, but at a low sensation level (less than 60 DB above the audiometric threshold The reflex may be present, but at a high sensation level (greater than 100dB above the audiometric threshold) --> elevated
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