Masking Flashcards
What are the 3 types of masking?
- Pure-tone Air Conduction
- Pure-tone Bone Conduction
- Speech
Define Cross-Hearing
When the presented sound is being presented to the test ear, its being heard in the NON-TEST EAR
For Cross-Hearing, how is the signal being heard in the NON-TEST Ear?
Since the signal that’s being presented is very loud to one ear, it crosses over and is heard in the opposite ear
For whom does Cross-Hearing occur? And why?
For patients that has asymmetrical HL, when we’re trying to get a threshold of the worse ear, we would end up testing and receiving results from the better ear since sound travels.
What’s the mechanism behind Cross-Hearing?
Even though the test is for Air Conduction, the cross-over is occurring through bone-conduction since the stimulus is so loud causes the skull to vibrate and in turn causes stimulation to both cochleae
For patients that has an asymmetrical HL, what criterions should we keep in mind?
- One ear can have some form of HL while the other has normal hearing or both or both ears has a HL but @ different levels
- The loudness of a sound and
- Its impact on how sound will travel to the next ear
Finish the sentence:
When sound presented to the worse ear….
is so loud it ‘crosses over’ to the better ear.
Define Interaural Attenuation
It’s the amount of energy loss as sound travels from one side of the head to the other
When does is being presented to one ear, even if it’s loud enough to cross over to the other, would there be a loss of intensity?
Yes, there will be a loss of loudness when it reaches the non-test ear
In what ways can the amount of interaural attenuation vary?
Interaural attenuation can vary with frequency, transducers, and slightly among individuals
What type of standard is used for Interaural Attenuation?
A conservative standard
What’s the interaural attenuation for Supra-aural earphones?
40 dB HL
What’s the interaural attenuation for Insert earphones?
70 dB HL
Between the Supra-aural phones & Insert phones, which one has a greater interaural attenuation?
Insert earphones
Why are inserts better than supra-aural headphones?
Since we don’t want the sound to be heard in the other ear, so the quitter the sound is when it gets to our better ear, the better off we’ll be
When does an issue arise for cross-hearing?
When a patient has an asymmetrical hearing loss
How do you know when cross-hearing is occurring?
If the level after interaural attenuation is the same or greater than the bone conduction of the non-test ear
What’s the formula for determining if cross-hearing will occur?
AC (te) - IA is > (greater than or equal to) BC (nte)
In the formula for determining if cross-hearing would occur, why is bone conduction present?
Because the method of cross-hearing is bone conduction since the way sound is able to travel from one side of the head is not through air conduction but it’s the vibrating of the skull that stimulates both cochlea and potentially getting a response from the better ear
If AC (te) - IA is > (greater than or equal to) BC (nte) what type of cross-hearing can occur?
A potential since everyone is different
What are the 2 problems when it comes to cross-hearing?
- Your threshold may not be accurate, and
2. You may be getting a response from the non-test ear
If AC (te) - IA is > (less than or equal to) BC (nte) is present, which ear is responding?
The non-test ear and you’ll need to mask
If you’re worried about a signal going to the non-test ear, what should you do?
Masking
Define Masking
Is presenting a noise to the non-test ear to keep it busy while re-testing threshold of the test ear
For Masked Air-Conduction Audiogram, what are the symbols?
RIGHT: Red triangle
LEFT: Blue square
For masking Air-Conduction, what does the triangle mean?
It means that a pure tone was presented to the RIGHT ear while you presented masking noise to the LEFT ear
For masking Air-Conduction, what does the square mean?
It means that a pure tone was presented to the LEFT ear, while you presented masking noise to the RIGHT EAR