Final Exam Flashcards
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
Whats wrong?
PE tube or Perf
below 1.5khz RECD will be up to 8db lower than the average
Whats wrong with TOP?
top: Mastoidectomy
open mastoid cavity decreases function in mid to high freq
Whats wrong with bottom
Bottom: Middle ear effusion
MEE increase RECD in mid to high frequencies - increased stifness of TM
Frequency lowering verification and modification
Verify Audibility of High Frequency /s/
- Goal is to add the least amount of FL required to put the upper shoulder of the /s/ response into the MAOF (maximum audible Output frequency range)
- Its recommended you leave FL disabled for the first few weeks for adults
what is the goal of frequency lowering?
Goal is to add the least amount of FL required to put the upper shoulder of the /s/ response into the MAOF (maximum audible Output frequency range)
what is aided functional gain?
The difference between the aided threshold and the unaided thresholds provided by the HA = functional gain
- aided threshold - unaided threshold = function gain
- measured using pure tone signals in the soundfield
how is aided functional gain measured?
measured using pure tone signals in the soundfield
reasons for using aided functional gain?
- REM equipment is not available
- Gooey cerumen clogs probe mic
- Pediatric fittings or uncooperative patients
- CI, BAHA, Lyric fittings
- Some federal government agencies require the test
these are things would list if Real ear wasnt practical
What’s the ideal aided threshold for aided functional gain?
- The ideal aided threshold should at least allow the lowest intensity level of normal speech to be audible
- Expected aided functional gain is often not achieved, especially in high frequencies
aided functional gain pitfalls
- Test-retest reliability is poor.
- Testing only identifies the threshold of audibility
- Limited number of frequencies assessed
- Ensuring WDRC successfully shaped the signal into a reduced dynamic range requires multi-intensity assessments
- Aided thresholds are invalid for near-normal hearing
- Hearing aid features could suppress audibility of tones:
- Loss of high frequency aided functional gain in nonlinear hearing aids is caused by AGC kneepoint
Efficiency of aided functional gain
every time you modify gain you need to perform aided functional gain measures
List alternative “conformity” (verification) protocols
- On- Ear Real Ear Verification
- RECD measurement and test box programming
- Aided Speech intelligibility Measures
- Aided verification of adaptive speech in noise performance
- Aided loudness ratings
- Subjective SF ratings
what conformity verification
* demonstrate improved intelligibiity
* demonstrate the benefits of technology designed to improve understanding in noise
* demonstrate continued limitations of hearing in noise and the benefits of speech reading
Aided Speech intelligibility Measures
Aided Speech intelligibility Measures
- demonstrate improved intelligibiity
- demonstrate the benefits of technology designed to improve understanding in noise
- demonstrate continued limitations of hearing in noise and the benefits of speech reading
what conformity verification
* Ensures SNR loss did not degrade with amp
* Functional verification of improved performance with directional or remote microphones
* use SNR loss results to counsel on aided hearing aid benefit
Aided verification of adaptive speech in noise performance
what conformity verification
* Patient is aided bilaterally and judges how loud the sounds are based on chart while listening to a passage
* 45 dB SPL = they should rate it a 1,2,3
* 65 dB = rate it 3,4
* 85 = be below 7
Aided loudness ratings
Aided verification of adaptive speech in noise performance
- Ensures SNR loss did not degrade with amp
- Functional verification of improved performance with directional or remote microphones
- use SNR loss results to counsel on aided hearing aid benefit
Aided loudness ratings
- Patient is aided bilaterally and judges how loud the sounds are based on chart while listening to a passage
- 45 dB SPL = they should rate it a 1,2,3
- 65 dB = rate it 3,4
- 85 = be below 7
- speech intelligibility judgements
* Patient judges ‘ease of listening’ while listening to passages presented at 50 dB HL - speech quality judgments
* Patient judges sound quality while listening to passages presented at 50 dB HL
Subjective Sound Field ratings
Subjective Sound Field ratings
- subjective speech intelligibility judgements
* Patient judges ‘ease of listening’ while listening to passages presented at 50 dB HL - Subjective speech quality judgments
* Patient judges sound quality while listening to passages presented at 50 dB HL
ANL similar
Describe the 3 considerations made to determine if manual memories are warranted
- How often are they in challenging environments?
- program that is noticeably different from the baseline
- patient can understand (or manage) additional manual programs?
manual program modifications to improve
Speech in a low-freqency weighted background noise
- Change the frequency response without changing compression ratio
- Reduce frequency shaping bands below 1.5k Hz to decrease audibility of the low frequency input signals
- ncrease frequency shaping bands above 1.5k Hz to improve audibility of consonant sounds
- Change the frequency response without changing compression ratio
- Reduce frequency shaping bands below 1.5k Hz to decrease audibility of the low frequency input signals
- ncrease frequency shaping bands above 1.5k Hz to improve audibility of consonant sounds
Speech in a low-frequency weighted background noise
- Raise LF threshold kneepoint (TK) below 1.5k Hz to 50 dB to attenuate interfering soft LF signals
- Increase CR in the LF loud input channel- “one step” (1-2 dB) this lowers the output of loud LF signals
Comfort listening in a low frequency (LF) weighted background noise
think 50 comfortable listening level
manual program modifications to improve
Comfort listening in a low frequency (LF) weighted background noise
- Raise LF threshold kneepoint (TK) below 1.5k Hz to 50 dB to attenuate interfering soft LF signals
- Increase CR in the LF loud input channel- “one step” (1-2 dB) this lowers the output of loud LF signals
- Change the frequency response without changing compression ratio
- Increase frequency shaping bands below 1.5k Hz to add richness & audibility to input signals
- Decrease frequency shaping bands above 1.5k Hz reduce annoying signals in this frequency range
High freqeuncy weighted background noise
manual program modifications to improve
high frequecny weighted background noise
- Change the frequency response without changing compression ratio
- Increase frequency shaping bands below 1.5k Hz to add richness & audibility to input signals
- Decrease frequency shaping bands above 1.5k Hz reduce annoying signals in this frequency range
- Raise the threshold kneepoint (TK) above 1.5k Hz to 60 dB this reduces audibility of soft HF input signals because they do not support intelligibility in this environment
- Increase CR in this HF loud input channel “one step” (1-2 db) this lowers the output of loud HF signals
Party noise
manual program modifications to improve
Party noise
Raise the threshold kneepoint (TK) above 1.5k Hz to 60 dB this reduces audibility of soft HF input signals because they do not support intelligibility in this environment
Increase CR in this HF loud input channel “one step” (1-2 db) this lowers the output of loud HF signals
- There is no ‘long-term average” and therefore targets prescriptive fitting formulas are unavailable
- Intensity & frequencies variations are significant
- Crest factor: Intensity maxima and minima are different than speech
- Crest factor of +16 to +18 dB whereas speech is assumed to be +12 dB
- The output waveform of music is “peakier” relative to speech
MUSIC
a patients frequecny & temporal resolution may limit oversall satisfaction
manual program modifications to improve
Music
Note, a patient’s frequency & temporal resolution issues may limit overall satisfaction of music
Complexities associated with musical signals
* There is no ‘long-term average” and therefore targets prescriptive fitting formulas are unavailable
* Intensity & frequencies variations are significant
* Crest factor: Intensity maxima and minima are different than speech
* Crest factor of +16 to +18 dB whereas speech is assumed to be +12 dB
* The output waveform of music is “peakier” relative to speech
assessing occlusion effect (shell origin)
How it’s diagnosed
* Prevalent when low frequency thresholds are better than 40 dB HL
* The complaint persists when the device is turned off
managing the occlusion effect (shell origin)
- Open vent,
- increase canal length
- If a non-occluding dome doesn’t allow enough high frequency gain due to feedback, a custom hollow-shell earmold with a 2mm or larger vent effectively allows low frequency energy to escape from the ear canal and offers significant reduction of occlusion-related complaints
Programming recommendations for ‘own-voice’ complaints (amplifier origin)
- Too much - or surprisingly - too little gain in the low frequency region can lead wearers to complain that their own voice sounds too loud.
- Try lowering LF band 4-6 dB for improvement
- If complaint persists, try increasing LF band 4-6 dB to overcome a combination of mild occlusion and under amplification
- Try the manufacturer’s fitting assistant
High frequencies, loud intensity, down 2-3 dB, big _____ change all frequencies of loud channel
Paper crinkling:
Paper crinkling:
High frequencies, loud intensity, down 2-3 dB, big paper change all frequencies of loud channel
High frequencies, moderate intensity, down high freq moderate channel
Plastic grocery bags:
Plastic grocery bags:
High frequencies, moderate intensity, down high freq moderate channel
All frequencies, soft intensity. Bring down high, then mid, then low each separately.
Nylon coat:
Nylon coat:
All frequencies, soft intensity. Bring down high, then mid, then low each separately.
High frequencies (4-8), loud intensity. Bring the high frequency, loud channel down.
Water running:
Water running:
High frequencies (4-8), loud intensity. Bring the high frequency, loud channel down.
Low frequencies and then high. Loud channel.
Toilets flushing:
Toilets flushing:
Low frequencies and then high. Loud channel.
Low frequencies, very soft intensity. Change expansion to more in the low frequencies.
HVAC Fans
HVAC fans
Low frequencies, very soft intensity. Change expansion to more in the low frequencies.
Signals louder than 90 dB
MPO
MPO
MPO: Signals louder than 90 dB
lower than 20 dB - depends what the ____ is for the device.
TK adjustments
TK adjustments
lower than 20 dB - depends what the TK is for the device.
TK = 20-50 dB
CR = 1.1:1 to 4:1
WDRC
kneepoints and compression ratios
WDRC
TK = 20-50 dB
CR = 1.1:1 to 4:1
TK = 80 dB
CR = 5:1 to 10:1
OLC
kneepoints and compression ratios OLC
TK = 80 dB
CR = 5:1 to 10:1
Describe how output changes when input level threshold kneepoints are lowered or raised.
- Adding gain at a low TK improves audibility of soft sounds. Low CRs shape sound into dynamic range.
- Shifting to a lower TK increases output for soft signals at or below the TK.
- Shifting TK to a higher input level decreases output for those soft signals.
- When TK decreases, there is more output gain of the soft input signals. The louder input signals do not change.
Adding gain at a low TK
Adding gain at a low TK improves audibility of soft sounds. Low CRs shape sound into dynamic range.
Low CRs
Low CRs shape sound into dynamic range.
Shifting to a lower TK
Shifting to a lower TK increases output for soft signals at or below the TK.
Shifting TK to a higher
Shifting TK to a higher input level decreases output for those soft signals.
When TK decreases
there is more output gain of the soft input signals. The louder input signals do not change.
The dynamic range of a digital microphone is limited by
The dynamic range of a digital microphone is limited by the A/D Converter’s digital bits
Describe two ways to reduce front end input distortion for loud input levels
- We can resolve this by increasing the bit size in the hearing aid or
- using the ADC (bridge thing) that can be raised to help with loud input but this also decreases the sensitivity of the soft inputs.
what is front end distortion?
Any signal that exceeds the dynamic range will result in front-end distortion
Name and describe each method of frequency lowering
(short)
- Linear frequency transposition
cut & paste - Nonlinear frequency compression
tonotopic order is maintained - Spectral Envelope Warping
copy & paste
Linear frequency transportation
Linear frequency transportation
* Moves a high frequency band one octave down to a lower frequency region
* the moved frequency components are mixed with any low frequencies present
Non-linear frequency compression
- High frequencies are compressed into a lower frequency range
- frequencies below the start frequency and end frequency are not altered
- Tonal topic ordering a frequencies is maintained
Spectral envelope warping
Spectral envelope warping
* Copy and keep approach
* High frequency signals are transported to a lower frequency band but simultaneously remains present in its original tonotopic position
services Medicare will reimburse?
Will
* Medically necessary procedures and assessments
* Test for a diagnosis
* Regarding changes in hearing
services Medicare will not reimburse?
Will not
* When the auditory/balance status is already known
* When the reason for the hearing assessment is related to HAs, or examinations for the purpose of prescribing, fitting, or modifying HAs (don’t mention HAs)
3 methods used to reduce external feedback
- Increase mold snugness, decrease vent
- Digital notch filtering
- Digital Feedback cancellation
list of comorbidities linked to hearing loss
Gastrointestinal: Crohn’s disease
Musculoskeletal: Rheumatoid arthritis, Fibromyalgia
Respiratory: Asthma
Cardiac: Congenital heart disease
Lymphatic: autoimmune disorders
Hematology: anemia, Leukemia
Integumentary: Shingles, Herpes zoster, Ramsay Hunt syndrome
Nervous system: Parkinson’s disease
What is
Digital notch filtering & cons
- Creates a notch in frequencies so we can not amplify to those frequencies
- Manually reduce gain between 2-4k Hz until feedback stops
Potential Con?
* Stops the audibility of important speech sound- reduced speech intelligibility
What is
Digital Feedback cancellation and cons?
- When a feedback path is detected, the phase cancellation algorithm mimics the feedback and creates a clone of this signal. Within the hearing aid, this clone is subtracted from the amplification path, therefore breaking the loop.
Cons: Entrainment - environment sound mimics feedback makes clone; patient can hear clone.
Functional limitations
Functional limitations: a problem in body function or structure
Ex: moderate SNHL
Activity limitation
Activity limitations: related to the difficulties experiences when executing a task or action (task of understanding speech in noise) (what they struggle with)
Ex: trouble hearing speech, hearing in noise, gathering meaning from speech
Participation restrictions
Participation restrictions: refers to involvement in activities an individual would like to participate in
Ex: “I avoid restaurants because I can’t hear in noise”, keeps TV volume too high, dropped out of school because it was too difficult, stopped working
Clinical uses for SII
- Helps healthcare professionals better understand threshold loss impact
- Reduced counseling mismatch between Audiologists and patient
- Helps audiologists determine amplification candidacy
- Shows objective audibility improvements with amplification
- Aided SII comparison allows you to see if one style, or brand of device supplies more audibility
*
Clinical uses for RMSE
- Root mean squared error
- considers how close the measured output is to the prescribed target. Should be within 5 dB
LDL rationale, clincal use
Rationale: tolerance levels vary significantly despite similar threshold loss
Clinical use: obtain objective data identifying the frequency-specific dynamic range to ensure output across frequencies does not exceed levels of comfort
Quick-SIN rationale, clincal use
Rationale: speech intelligibility in noise remains the #1 improvement patient seek with hearing aids
Clinical Uses
* Completion of the test instills patient confidence in your skills: “I’ve had lots of hearing tests. This is the first time anyone really tested my hearing!”
- Results supply quantifiable data:
- Supporting use of evidence-based recommendations for technology for improved hearing in noise
- Helping patients understand improved communication requires more than restoration of threshold loss
- Remember, degraded frequency and temporal resolution may continue to limit hearing in noise despite well fit amplification
- Increases clinical efficiency by reducing unnecessary office visits
ANL rationale, clincal use
Rationale: quantifies a listener’s willingness to listen to speech in the presence of background noise.
Clinical use: Predictive of hearing aid satisfaction with 85% accuracy
Identifies those who will have more difficulty adapting to amplification
How will the questionnaire support the F&CNA?
- assists with comprehensive identification of all technology needs
- selection of hearing instrument style
- features needs
- hearing assistive devices
- counseling on realistic expectations
Clinical use of the COSI
prioritizes patient-centered treatment goals
ranks perceived importance of up to 5 situations causing the greatest communication problems
Cognitive goals
Cognitive: defines difficult environments that require improvement to reduce the impact of the impairment
Affective goal
Affective: defines desired improvements as they relate to feelings/emotional needs.
Why is it beneficial to consider both cognitive & affective types of goals in your plan of care
Why both? To learn more about what will benefit the individual in their daily life and what will not, along with learning more about their surroundings they experience throughout the day. You will also learn what they are experiencing and how we can make it better.
8 warning signs of ear disease
- deformity of the ear
- active drainage from the ear with in the previous 90 days
- Acute or chronic dizziness
- sudden or rapidly progressive hearing loss within the previous 90 days
- Unilateral hearing loss of sudden or recent onset within the previous 90 days
- Audiometric ABG > 15 dB at 500, 1000, and 2000 Hz.
- Visible evidence of significant cerumen accumulation or a foreign body in the ear canal
- Pain or discomfort in the ear
Measurement of the absolute SPL level of an open ear canal resonance, across all frequencies, at the TM
REUR
REUR & why
Measurement of the absolute SPL level of an open ear canal resonance, across all frequencies, at the TM
Why do we measure?
Knowing a patient’s ear canal resonance improve accuracy of prescriptive fitting
REUR changes due to differences in size, texture, shape, or presence of abnormal anatomy
a measurement of insertion loss caused by placing an earmold/dome in the ear canal
REOR
REOR & why
- a measurement of insertion loss caused by placing an earmold/dome in the ear canal
Why do we do it?
* Measurement identifies which low frequencies are released due to the vent effect
* The measurement shows if the vent introduced undesired standing wave effects that would impact amplification characteristics
the absolute aided output and frequency response when a hearing aid is turned on
REAR
REAR and why
- the absolute aided output and frequency response when a hearing aid is turned on
Why do we do it?
* the view the devices absolute aided output in a unique ear canal
difference in decibels across frequencies, between an ear canal resonance and the resonance of the 2cc coupler
recd
RECD & why
- RECD is the difference in decibels across frequencies, between an ear canal resonance and the resonance of the 2cc coupler
Why we do it
* Converts an individual’s HL thresholds to SPL
* Supplies adjustments for differences in canal volume and impedance variations
