final exam with review Flashcards
challenges of fitting a reverse slope loss
the addition of too much gain within the LF’s can lead to upward spread of masking as well as satisfaction may be limited due to increased likelihood of extensive dead regions
fitting strategies with a reverse slope loss
-add 15-20 dB gain to the low and mid frequencies
-add 10-15 dB at 2kHz and above for increased audibility
-allow time for habituation before any additional increases
what is important when we interact with patients that have a severe to profound hearing losses
we have to think of every patient individually, no two are the same
-residual hearing depends on individual factors
-be aware they may not be able to process speech due to the degree of loss
audibility objectives with severe to profound loss
need to consider communication style and patients may be more dependent on a specific signal processing type (i.e. some may prefer linear or nonlinear)
fitting strategies with a severe to profound loss
-raising up the TK may result in more access to the sounds that are more important to them
-lower compression ratios (closer to linear)
-slower acting compression to maintain longer non-compressed state
-using NAL-RP is recommended
-ensure to raise MPO as high as we can while staying under LDL
with severe to profound loss, these people tend to prefer _______
linear
fitting strategies needed for conductive loss
additional gain is needed to overcome the attenuation caused by the mechanical loss
-NAL formula is recommended
fitting with perforations
-losses that need LF energy will need ventilation
-BTEs are the only option for these patients to allow circulation
-NAL 2 is used
challenges with A/B gaps and fitting
these gaps attenuate the amplification prior to when it arrives to the cochlea
-additional gain will be needed to overcome these gaps
how to overcome the A/B gaps in fitting
calculate prescriptive gain that is recommended for the AC thresholds
-calculate 25% of the gaps
-increase the MPO by the same percentage allowing headroom for the extra gain
-use NAL as it calculates for this
two reasons as to why we measure RECD
it accurately converts an individuals HL audiometric thresholds into dB SPL values and it can allow for a prediction of real ear output when HA measurements are made within the test box
what is the importance of gaining personalized conversions from an RECD
the HL of two patients may be the same however the SPL can vary based on their individual ear factors
-if we use average data, this can lead to over or under amplification
how will slit leaks present on an RECD measurement
there will be a negative RECD within the LF
-can check the seal
-if that does not fix it, you can increase the tip size or use aquaphor
how will a blockage present on an RECD measurement
there will be a negative RECD within the HF
explain how ear canal volume can impact the SPL
-the smaller the volume, the higher the SPL (needing some more gain)
-the higher the volume, the lower the SPL (not needing as much gain)
why will we see changes in the RECD with patients that have perfs or PE tubes
with these two conditions, we have the additional of the ME cavity while measuring the volume
-we will see that LF energy is being released into the ME cavity o these lows are impacted more often
-therefore, the RECD will be decreased!!
why will we see changes in the RECD with fluid
the eardrum becomes stiffer and gets smaller, becoming a different system with different movements
-the RECD will be increased due to a smaller volume
why will we see changes in the RECD with a mastoidectomy
the ear canal space is impacted so therefore we will see a larger volume and therefore the RECD will be decreased
if there is a larger volume, the RECD will be _______. if there is a smaller volume, the RECD will be _______,
decreased ; increased
what are the steps that should be completed prior to the first fit appointment
conduct ANSI measurements, program the HA using RECD data and perform a listening check
frequency lowering is not recommended to be turned on at the first fit appointment however during the programming we can turn it on to observe. what are we doing to see how it functions?
we assess FL both with it off then with it on while playing a /s/ signal within the test box
-we are observing for the MAOF to become audible with their thresholds
day of delivery appointment notes
ensure a conformity evaluation is ran, perform speech map at 65 dB only, we can lower the volume if needed based on the perception from the patient and we are able to use speech map as a counseling aid to help show the patient what speech they hear and what they miss
functional gain (FG)
compares the patients unaided sound field audiogram to the aided audiogram
-this needs to be tested using soundfield for both the unaided and aided!!!
how is FG assessed
there is a pulsed or warble tone presented while masking is presented to the other ear using inserts
-the opposite ear is tested with the device through soundfield
-testing 500 to 4kHz
common reasons for measuring FG
REM equipment may not be available, cerumen may clog the probe microphone, pediatric fittings or uncooperative patients, CI/BAHA/lyric fitting and some federal government agencies may require it
with FG, we are not looking to achieve 0 dB for aided. what is a ballpark value we are looking for
around 20 dB
limitations of FG
test-retest is poor (could vary as much as 20 dB from day to day), testing only identified threshold of audibility, aided thresholds are invalid for near normal hearing, limited number of frequencies tested, HA features could suppress audibility of the tones, loss of HF aided functional gain is caused by AGC knee point
to ensure efficacy of aided function gain, when do these tests need to be performed?
after every modification to gain
what are the alternative conformity protocols
aided speech intelligibility measures, aided verification of adaptive speech in noise performance, aided loudness ratings and subjective soundfield ratings
aided speech intelligibility measures
checking to see if the audibility we added improved the ability to detect speech
-present speech through sound field
aided verification of adaptive speech in noise performance
ensures SNR loss did not degrade with amplification and functional verification of improved performance
-QuickSIN that is performed in the soundfield
-we need to adjust the signals manually, so after each sentence we increase the noise by 5 dB
what is the starting SNR for QuickSIN
+25 dB
-meaning the signal is 25 dB louder than the noise
aided loudness ratings
aided bilaterally and provide the patient with the loudness chart
-deliver a 45 dB signal (1-3 is acceptable)
-deliver a 65 dB signal (3-5 is acceptable)
-deliver a 85 dB signal (5 or 6 is acceptable)
subjective soundfield ratings
both subjective speech intelligibility and subjective speech quality judgements
3 considerations to determine if manual memories are warranted
how often they are in challenging environments, can the patient hear the difference and would the patient be able to understand/manage the programs
how often would a patient need to be in challenging environments to benefit from multiple memories
frequently!!
-with occasionally, you would need to determine with additional questions
-people that are rarely in challenging environments are not needing programs
what factors would impact the ability for a patient to hear the difference between programs
configuration does not require LF gain/output, feedback limits ability to add HF gain/output, receiver size limits the output and can’t increase the CR further
what factors would allow the patient to hear the difference between programs
threshold at 500 Hz is better than or equal to 40 dB and that the HF loss is not too severe
what factors decide if a patient could be able to understand/manage the programs
have the patient describe when they would use the programs, can the patient manipulate the control and can also screen for any mild cognitive impairment
what is the goal when creating a program for speech in low-frequency weighted background nosie
to eliminate the offending signal (within the lows) while increasing the high frequencies for clarity
changes that should happen for speech in low frequency background noise
-lower the low frequency band from 1kHz to 250 Hz (most at the very lowest)
-raise the high frequency band from 2kHz to 4 kHz (most at the very highest)
changes that should happen to improve comfort listening in low frequency weighted background noise
-raise the low frequency TK below 1.5 kHz to attenuate the soft LF signals
-increase the CR in the LF loud input channel (done by decreasing the gain)
changes that should happen for high frequency weighted background noise
increase the bands of LFs (the most at 250 Hz and the least at 1 kHz) and then decrease the bands of HFs (the most at 4 kHz and the least at 2 kHz)
what is the goal of programs for party noise
improving the comfort and striving for tolerance
what are the complexities with making a program for music
no long term average, intensity/frequency variations are significant and the intensity max/min are very different than speech (can be up to 16 to 18 above whereas speech is 12 above)
management of the amplifier origin
lower the LF band 4-6 dB
-if still present, try increasing it to overcome the mild occlusion and under amplification
how to assess the management for the shell origin
we can push the HAs further in then pull it out slightly, if the complain is better when it is deeper change the canal length but if the sound is better when it is pushed out change the vent
changes that should happen for party noise
-raise TK for HF up to 60 dB for attenuation of the soft HF signals
-increase the CR in the loud input channels (taking the edge off)
management of the shell origin
open vent or increased canal length
fitting suggestions for music
select a HA with a microphone that allows high front end input range or ….
-lower the volume on the stereo while increasing the volume on the aid
-use FM system as the input source instead of the device microphone
-place 3 layers of scotch tape over microphone to attenuate input by 10 to 12 dB
changes that should occur within a dedicated music memory
-disable DFS, DNR, adaptive directional microphone and frequency lowering
-reduce CR in the low frequencies by raising gain for loud input signals
-raise MPO to improve brightness/crispness
how can we tell if it is shell or amplifier origin
if the complaint is there with the device turned off, it is shell. if the complain stops when the HA is turned off, it is amplifier origin.
what are the two origins for the occlusion effect
shell and amplifier
TK adjustments
best for adjusting the soft channels or any signal below the TK
-don’t forget about expansion below the TK
MPO adjustments
best for adjusting the loud channel or any signal that is greater than 65 dB
-this can introduce more headroom
what are some scenarios when we would change the TK
if the HA does not have expansion (raising the TK) or if you want the patient to hear more soft consonant sounds (lowering the TK)
what does medicare reimburse
diagnostic procedures needed to diagnosis a patient
-annual or recurrent services are not covered
-audiologic treatment is not covered
who can be reimbursed
the audiologist is the only one unless the state allows for a physician to be reimbursed
medicare requires medical necessity, what are some examples of this
must be necessary based on diagnosis or symptoms, re-evaluation due to suspected change in hearing/tinnitus/balance or to investigate the cause of a disorder
bundling billing practices
consumer prepays for all the current and future services at the time of the purchase ; one flat rate up front
-generally the HA cost + $1000
benefits of bundling services
practice can estimate the revenue generation based on number of amplification units dispensed each month and billing protocols are less complicated
bundling does not recognize everything we give away such as ….
time spent completing FCNA, time spent on quality control checks or programming, time spent programming or finetuning, time spent on HAC, in office repairs
when we charge a single price for a HA with all of the services, it shows the patient ……
that the HA is costly but our time is free
unbundling billing practices
separates the cost of technology from all other associated services
-the patient is in control of what they can pay
benefits of unbundling services
allows consumer to differentiate the cost of the device from your services, provides the consumer with the opportunity to be selective in choosing the level of services, allows consumers to purchase devices through other platforms and then receive only the service component from the audiologist
challenges with unbundling services
3rd party payers expect providers to unbundle billed services, knowledge of reimbursement fee schedules to determine the combination of codes needed to optimize payments is time consuming
even though CROS and BiCROS devices technically have two devices, they are considered _________ when coding
one HA
when billing for batteries or molds, how do we code
code as units
-we code for the amount given to the patient
common comorbidities linked to HL
GI (crohn’s disease), musculoskeletal (RA), respiratory (COPD), cardiac (poor circulation), lymphatic (autoimmune disorders), hematology (anemia), integumentary (shingles), nervous system (parkinson’s) and endocrine system (kidneys diseases)
what are common comorbidities in older adults
visual impairment, cognitive issues, depression, falls and hypertension
functional limitation
problem within the body function/structure
activity limitation
difficulties experienced when executing a task or action
participation restrictions
involvement in activities an individual would like to participate in
speech intelligibility index (SII)
what is audible to the patient and what is not audible
-helps the patient better understand their diagnostic findings
-clear understanding of their abilities
root mean squared (RMSE)
considers how close the measured output is to the targets
-a difference between the probe output and targets
loudness discomfort level (LDL)
objective measurement of the dynamic range
-used to measure the MPO
the average LDL is around 100. if our patient has a lower LDL, what does this potentially mean for amplification
may need slower paths to technology and might need habituation into amplification
frequencies to test for LDL
always measure at 2 and 3 kHz
-skip measurement for any frequency with normal sensitivity
-are the LF thresholds greater than or equal to 40 dB HL
-does the device supply output in an extended frequency range
what can the QuickSIN tell us about the patients amplification
with a higher than typical score (over a +2 dB signal) these people would have more success with premium technology as this gives the best directionality
how is the ANL found
subtracting the BNL from the MCL
-MCL from channel 1 and BNL is channel 2
-remember the BNL is played with the MCL on to see at which point it overwhelms them from audibility
with ANL the small scores (below 7 dB) require no changes to the fitting. however if a patient has a high score (over 13 dB) this requires changes. what are these?
these patients are less likely to wear the HA’s so we need to counsel on habituation
-giving the patient realistic expectations
-premium technology would be beneficial
-directionality!!
what must a functional and communication needs assessment identify
activity limitations and participation restrictions, environmental factors which may impact plan of care and personal factors which may impact plan of care
when assessing patient factors, we often give out questionnaires. explain the benefits
questionnaires allow comparison to normative data and they are completed independently prior to the appointment
what is the COSI
prioritizes patient centered goals
-cognitive goals (desired environments that require improvements)
-affective goals (desired improvements relating to feelings/emotional needs)
8 warning signs that indicate medical evaluation should occur
deformity of the ear, active drainage within the previous 90 days, sudden or rapidly progressive HL within the previous 90 days, acute/chronic dizziness, unilateral HL within the previous 90 days, ABG at 500/1000/2000 Hz, significant cerumen accumulation and pain in the ear
real ear unaided response (REUR)
measurement of SPL at the TM
-measured with an open canal
real ear unaided gain (REUG)
calculation of the difference between the input arriving to the TM and the output leaving the TM
real ear occluded response (REOR)
measuring the output arriving to the TM when the canal is occluded
-can tell us if the vent effect is releasing the lows as it should
real ear occluded gain
looking at insertion loss
real ear aided response (REAR)
the increase in gain arriving to the TM when the HA is turned on
real ear insertion gain (REIG)
the difference between the aided and unaided response
REAR 85/90 (MPO)
measures the intensity of the output signal arriving to the TM when the input is sufficiently intense to drive the device to its maximum power
what are the output requirements to achieve binaural benefit
15 dB
type 1 test signal vs. type 2 test signal
type 1 : pure tone swept over frequencies
type 2 : complex speech like signals with random frequencies
long term average speech spectrum (LTASS)
a frequency dependent measure of time average sound pressure level of speech
-measuring sound over time through a looping passage
what are the levels of the speech envelope? speech envelope peaks? speech envelope valleys?
30 dB ; +12 dB ; -18 dB
why does probe module calibration result in an acoustic transparency between the reference microphone and probe tube
since probe tube is placed directly over reference microphone during calibration and this accounts for the different intensities arriving to the probe microphone modules reference microphone and through the probe tube
-the unit adjusts the intensity difference by removing the tubes resonance effects
how does reference microphone contamination occur
reference microphone contamination occurs when the amplified output escapes the ear canal through open domes
-reference microphone measures and reacts to the intensity of the HAs output signal lowering the intensity of the speakers input signal
loudness normalization approach
theorizes aided loudness perception should be the same as normal loudness perception
-looking at how much output is needed to arrive to the TM to be perceived as soft, moderate and loud
-utilizes REAR
loudness equalization approach
recognizes audibility of mid and high frequency cues are critical for intelligibility
-based on threshold and audibility to determine how much gain to add
-utilizes REIG targets
DSL formula
loudness normalization
-maximizes audibility to assist with language development
-TKs are based on degree of loss
-expansion is applied to the low input levels
NAL formula
loudness equalization
-focusing on the higher frequencies as these support the most speech intelligibility
-based on the SII
-provides targets for both tonal and non-tonal languages
-calculates for A/B gaps
-good for people with severe to profound HL
is it acceptable to apply gain that does not meet the +/- 5 dB criteria
it is good to use the +/- 5 dB rule when fitting patients however we can move away from that rule based on what our patients is experiencing
-based on patients loudness or sound quality perceptions as long as the output measurement follows the recommended prescriptive contours
fitting strategies for dead regions
may be needed however we cannot assume that they need reduced HF output
-fitting is based around adding gain to the healthier areas of the cochlea
when is frequency lowering good to use
steeply sloping HL or severe to profound losses
-this is not recommended at the initial fitting appointment
challenges for fitting type 3 NIHL
OHC damage leads to recruitment, damaged/absent IHC can cause distortion, HF output is limited by feedback and full HF audibility is not a good goal due to comfort
fitting strategy for type 3 NIHL
add gain to the thresholds below 85 dB
-strive for balance of audibility from 500 to 3000
-add 5 to 8 dB of gain to normal thresholds prior to precipitous drop
-enable expansion to reduce microphone noise
-if the threshold is near the LDL, apply no gain or .25 of the threshold
frequency resolution
the auditory systems ability to detect discrete frequencies in the cochlea
-not fixable with HA’s
what damage can impact frequency resolution
damage to the cochlear hair cells
-this impacts the sharpness of tuning curves
-detecting those changes in speech
temporal resolution
auditory systems ability to detect small time related changes in the acoustic stimuli over time
-not fixable with HA’s
what occurs when temporal resolution is impacted
there will be an impacted ability to detect small breaks between sounds and words
-they all blend together impacting ability to follow conversation
benefits of spatial hearing
localization !!!
-can help with focusing on one signal and suppress the other signal
how does spatial hearing function
it sorts out the signals and can assist in binaural summation or binaural squelch
when you raise the TK, the output _________
the output becomes decreased
when you lower the TK, the output ____________
the output becomes increased
front end distortion
occurs when the collected/incoming signal exceed the microphones dynamic range
-exceeds the limit of the HA
why do digital HAs have a lower dynamic range
digital HA’s use analog to digital converts which uses a 16 bit that supplies a 96 dB dynamic range
-leads to peak clipping and distortion
how is front end distortion managed within digital HA’s
they have the ability to shift the dynamic range to fit the listening situation
what is the only feature that can be added in order to improve speech intelligibility
directional microphone
how are receivers designed to achieve the greatest high frequency output
smaller receivers give more higher frequencies due to having a smaller diaphragm
3 methods to reduce external feedback
reduce external feedback loop, digital notch filtering and digital feedback cancellation
3 types of frequency lowering
linear frequency transposition, nonlinear frequency compression and spectral envelope warping
how is fitting changed for A/B gaps with normal bone thresholds compared to A/B gaps with abnormal bone thresholds
with normal bone thresholds: compression is not needed because the dynamic range is normal
with abnormal bone thresholds: compression is needed in addition with extra gain to reduce the dynamic range
CROS vs. BiCROS device
CROS : a normal ear and a dead ear in which the dead ear transmits the signal to the normal ear for hearing
BiCROS : a better ear and a dead ear in which the dead ear sends the signal to the better ear which is amplified to hear
what calibration method is used to prevent reference microphone contamination
stored equalization
how does microphone contamination underestimate the output arriving to the TM
if the sound picked up by the reference microphone is louder than the speakers input, the algorithm will turn down the speaker
-this results in the aided response being lower than the actual output arriving to the TM
what considerations should occur prior to modifying any programs
-is it a problem that can be fixed through counseling
-will fixing this problem create a new problem
-will the problem solve itself over time through acclimatization
-can it be solves through adaptation or are there changes that need to occur
importance about systematic fine tuning
-establish a baseline setting for comparison (the original program)
-changes should be significant at first (larger steps then decrease)
-track the adjustments made so we can return to baseline
complaints associated with own voice issues
voice is hollow, sounds like they’re talking in a barrel or its annoying to eat crunchy foods
channel interaction
with the change of one channel, this can impact other channels as well
-we need to pay attention to the output change but also the output changes in additional channels
