Week 1 Flashcards
Suprathreshold detection abilities vary in terms of
- sound clarity and speech recognition
- acoustic signal encoding associated with: frequency resolution and discrim.
Temporal processing
Loudness perception
Who used tonal stimuli for the contour test
Cox 1997
What is the contour test
Scale of loudness 1. Very soft, soft, comfortable but slightly soft, comfortable, comfortable but slightly loud, loud but ok, uncomfortably loud
What does damage in the auditory periphery cause?
Outer hairstyle loss leads to more linear Basler membrane displacement, and we lose the frequency specificity
Low intensity, what type of range exist for the basilar membrane displacement
Narrow range
Increase in intensity means we see a watt of basilar membrane displacement
Broader range
With functioning out her hairstyles, what do we expect to see?
Gain occurring at specific locations on the BM (frequency specificity)
A passive response is associated with bm what
A loss of specificity and gain associated with active hair cells
How does the dynamic range of the BM change for normal hearing versus damaged hair cells
Normal has a wider dynamic range
With what type of hearing loss is abnormal loudness perception associated with recruitment occur
Sensory neural hearing loss
Related to a cochlear loss without hair cell damage
LDL
Loudness discomfort level
Level at which sounds become uncomfortably loud,
reflect tolerance to loud sound
Abnormal loudness perception without HL is associated with
Hyperacusis
Hyperacusis
Sensitive to sound at any level but normal or near normal threshold
May co occur with tinnitus
Unknown cause
What is hidden hearing loss?
Issues with speech and noise, hyperacusis, or other tinnitus
Individual has auditory damage without having significant hearing loss identified
Why is it important to measure LDL?
Used to assess hyperacusis
Gives a glimpse into the patient’s experience
Good to know for amplification, because the patient may reject the hearing aid if the MPO is beyond the limits
Significantly lower than expected it can remove the dynamic range
LDL Hawkins procedure
Ascending method in 2 DB steps
Lowest intensity -1db where uncomfortably loud on 2/3 trials
Use warble tone and insert
LDL Hawkins scale
- Very soft
- comfortable but slightly soft
- Comfortable
- Comfortable but slightly loud
- Loud but ok
6 uncomfortably loud - Extremely uncomfortable
- Painfully loud
A study compared Hawkins with beskey procedure what did they find
Hawkins had small fluctuations 3-4db
Mcl
Most comfortable level
Level or range designed by an individual as most comfortable for listening
Does not have a standardized accepted clinical method
How much can MCL change if you’re listening for intelligibility versus comfort
It is five DB higher for an intelligibility on average
What is the potential issue with fitting to MCL
MC I was typically five DB lower than what we would expect for good intelligibility so if the hearing aid is fit to MCL, it may not be Max audibility
Martin and Clark procedure
Find MCL by starting at a speech signal slightly above the SRT use an ascending approach, increasing intensity in five DB
Punch procedure
Conduct LDL, ascending MCL, and then descending MCL
If you test MCL or LDL first, it can elevate the MCL, because preceding sound serve as a reference for loudness judgements
what is a PIPB function
graph of the WRS vs the presentation level in dB
- at someones threshold they will get 0% correct
how does PIPB differ in CHL to normal
need larger initial input but then similar
how does PIPB differ in SNHL to normal
- depends on slope of HL and configration, variable degree of recruitment
- PBmax wont be best MCL for those with SNHL
if people have the same audiograms do they have the same sNHL
no they could have different underlying pathophysiology and different experieneces
