Final Exam Flashcards
(120 cards)
Challenges and fitting strategies when A/B gaps are present
- Additional gain is needed to overcome the attenuation caused by the mechanical loss
- ABG attenuate the signal amplitude before it arrives to the cochlea
ABGs with normal BC thresholds
compression is not needed because the dynamic range is normal
* Use of 1:1 linear signal processing (or very low CR) is fine
ABGs with abnormal BC thresholds (mixed loss)
Compression is needed in addition extra gain due to the reduced dynamic range
Explain why it is beneficial to measure the RECD on every adult’s ear canal
- Accurately converts an individuals HL audiometric thresholds to SPL (more personalized)
- Using RECD conversion values calculates ear canal SPL within 1 dB creating customized conversion values to create accurate fitting targets
what accurately converts an individuals HL audiometric thresholds to SPL (more personalized)
RECD
Using RECD conversion values calculates what?
Using RECD conversion values calculates ear canal SPL within 1 dB creating customized conversion values to create accurate fitting targets
Define RECD procedures based on ANSI Standards
- RECD measurement can be made with a custom earmold or EAR insert
- The same coupler for BOTH measurements
- The ANSI standard requires use of the HA-1 coupler
What do the RECD ANSI standards mean by the same coupler for both measurements?
This means you use a foam tip to measure the ear canal resonance AND the HA-1 coupler resonance
OR…
Use a custom earmold to measure the ear canal resonance AND the HA-1 coupler resonance
The ANSI standard requires use of what coupler?
The ANSI standard requires use of the HA-1 coupler
Be prepared to interpret RECD data
Describe the expected impact of slit leaks on RECD values
A negative LF value suggests a slit leak is present
- For correction, check the seal of the foam tip
A good RECD the “difference” should be
RECD: the “difference” should be a positive value
Describe the expected impact of blockage on RECD values
A negative RECD >10 dB in the 4– 6 kHz region suggests your probe tube is blocked
A negative RECD _____ dB in the _____ kHz region suggests your probe tube is blocked
A negative RECD >10 dB in the 4– 6 kHz region suggests your probe tube is blocked
How does the presence of perforation or PE tube impact the measured RECD
Negative LF results are expected when perfs or PE tubes are present
- Below 1.5 kHz, RECD will be up to 8 dB lower than the adult average
* This indicated the ear canal volume is larger than normal
If the RECD is above the dotted line/average this means what?
Samller canal than average
If the RECD is below the dotted line/average this means what?
Larger canal than average
A negative LF value suggests a
A negative LF value suggests a slit leak is present
A negative RECD >10 dB in the 4– 6 kHz region suggests
A negative RECD >10 dB in the 4– 6 kHz region suggests your probe tube is blocked
Below 1.5 kHz, RECD will be up to 8 dB lower than the adult average suggesting
PE tube or Perf
This indicated the ear canal volume is larger than normal
Below ____ Hz, RECD will be up to ____ dB lower than the adult average for PE tubes or perfs
Below 1.5 kHz, RECD will be up to 8 dB lower than the adult average
What is wrong?
Slit leak
A negative LF value suggests a slit leak is present
What is wrong?
Blocked probe tube
>10db in 4-6khz region