Final 712 Flashcards
1
Q
What does a test box measure?
A
The performance of a hearing device in a controlled simulated environment
2
Q
When are test box measures done? (4)
A
Before the hearing aid leaves the manufacturer
Before fitting a device in the clinic
Troubleshooting a patient complaint
After a hearing aid has been returned from a manufacturer repair
3
Q
What can a test box do? (3)
A
Produces sounds of specific SPL
Attenuates ambient noise
Minimizes reflected sounds reaching the HA
4
Q
What are the two HA couplers and what type of HA’s use each?
A
HA1 uses customs and RICs
HA2 is only for BTEs
5
Q
When do we use putty?
A
Helps to seal sound in to make sure measurements of the HA is accurate is EAA
Usually used with customs because they are not standardized (it would cover the sound bore and vent)
6
Q
Basic test box procedure
A
- couple the HA to the test box (ensure it is oriented the correct way, the front mic should be facing the front speaker)
- Paly specific types of measurement signals through the test box speakers (pure tone, broadband, speech)
- record the HA response to the signals
- compare the final measurement to a standard
7
Q
Which ANSI standard defines HA performance?
A
ANSI S3
8
Q
Why do we use ANSI standards?
A
Used as a quality check to determine HA performance
Provides equal ground with which to tell all HA (standardized measurement)
9
Q
What is IEC?
A
International electrotechnical commission
Europe’s equivalent to ANSI
10
Q
Full on Gain (FOG)
A
Gain control of HA is set to maximum output, this will generate a curve
11
Q
High frequency average (HFA)
A
Average gain or SPL in decibels at 1000, 1600 and 2500
12
Q
OSPL 90 curve
A
Reflects how the HA responds to a 90 dB SPL input when the HA is set to max gain
OSPL is the maximum output level if the hearing aid measured with a 90 dB SPL input signal (how loud is the HA capable of being)
13
Q
Why is 90 dB used for the OSPL 90 curve?
A
Nearly always enough to saturate the HA
14
Q
Reference test gain
A
HFA gain for an input of 60 dB when set to reference test position
15
Q
Acoustic gain
A
At each frequency, the result obtained by subtracting the input SPL from the SPL coupler
What went in compared to what went out
This will have two gain values
16
Q
Attack time
A
Time between the abrupt increase from 55 to 90 dB SPL and the point where the levels have stabilized within 3 dB of the steady state value for 90 dB input
How quickly does compression start after the onset of a loud sound
17
Q
Equivalent input noise level (EIN)
A
Measurement of the internal noise (comparison between no sound and 50 dB input)
18
Q
Reference test setting of the gain control (RTS)
A
Reduces volume to a position that will not saturate the hearing for mid-level input signals
Battery drain is measured at RTS
19
Q
EAA steps with verifit 2
A
Calibrate, position HA in test box with correct coupler, connect HA to manufacturer software and begin test settings, FOG, RTS/gain, return HA to user settings, analyze measurements according to published spec sheet and ANSI tolerances
20
Q
How do you calibrate the test box?
A
Under the test box test options, select calibration
No couplers are attached during this
21
Q
Why do we need to calibrate?
A
Need to make sure that all measurements run in the test box are standardized and can be compared to each other and ensures that equipment is working
22
Q
Positioning the HA in the test box with the correct coupler
A
EAA is always completed using blue coupler set
TRIC adapter attaches to HA1 coupler, otherwise would have to use putty- receiver should be pulled through but maintaining a tight seal
HA is centered over the “x” with front mic of the HA facing the front test box speaker
Reference mic is bent around to point at the front mic of HA
All HA run on the blue left coupler mic
23
Q
How to run FOG?
A
Connect HA to manufacturer software using correct programming device and locate “test settings”
Some software do not have test settings, requiring the audiologist to put the HA into FOG and RTS manually (turn off all automatic features like feedback and noise management then max out programming bands for FOG, adjust gain down for RTS
On the verifit, under test box tests can select ANSI/IEC and follow directions
24
Q
How to run RTS/gain?
A
Once FOG measurements are complete a green triangle will appear with the directions to “set VC to RTS”
The triangle with all but disappear once the HA has been programmed correctly
25
EAA with verifit 1
1. test box measures
2. HA1 coupler (RICs and customs require putty and attach to HA1 coupler, sound bore should be as close to the entrance of the coupler as possible, all couplers are silver)
3. positioning (verifit 1 speakers are labeled left and right instead of front and back so have to orient HA mic to face the left speaker)
4. attack and release (attack and release are rarely measures any more, seen in verifit 1 AGC seen, best to run attack/release with compression settings at maximum)
26
What are the differences between EAA with verifit 1 compared to 2?
Screen interface, but the list of options are mostly the same
Only 1 set of couplers for 1
Positioning in the test box is at an angle instead of front and back speakers
Additional test measurements require no change of position or equipment while verifit 2 does
27
What does it mean when a HA has no "test settings"?
Need to place HA in FOG and RTS manually using the programming bands
Turn off as many automatic features as possible (feedback, whistle block, noise suppression, frequency lowering)
FOG (max out all gain and MPO settings)
RTS (reduce programming band until green triangle disappears)
28
Measurement tolerances
Max OSPL 90- plus/minus 3
HFA OSPL 90- plus/minus 4
HFA FOG- plus/minus 5
RTG- HCC uses plus/minus 2
Total harmonic distortion- 3%
EIN- HCC uses less than 30
29
What do you do if the HA fails EAA?
Check coupling and placement in the test box
Can any part of the HA be repaired in the office? (may be able to replace the receiver for a RIC, an earhook for a BTE and clean the mic/wax traps for a custom
Once you have ruled out other causes of failure you will need to send the HA to the manufacturer for repair because internal electronic parts can only be replaced by the manufacturer
30
Why may you not complete EAA?
Trust in the manufacturer- companies often include test box runs with many of the repair invoices
Time
Uncertainty of the test procedures
Cost of test equipment
31
What are three questions that can be asked about EAA?
Is EAA warranted?
Is EAA efficient?
Is EAA cost effective?
32
Cost/benefit of EAA
HA with faulty electronics can often fly under the radar for a while
Having an objective way to test a HA takes all the guesswork out
Lots of repeat troubleshooting appointments waste time and money
Fitting a brand new HA with electronic problems greatly decreases the patient confidence in the whole process
Add value to your practice
33
When might you use a test box measure?
New HA from manufacturer
Repaired aid back from manufacturer
Check for excessive intermodulation distortion
Check for directional microphone response
Patient complaint not resolved by cleaning or simple repairs
34
Define DSP
How the hearing aid converts acoustic sound into digitized codes
35
Define sampling rate
Number of times per second that the hearing aid analyzes incoming sound at regular intervals
This is what differs between tiers
36
DSP helps make what possible
Frequency channels, compression, noise reduction, feedback suppression, directionality of microphones
37
Advantages of DSP
No noise in the digital conversion process
Sound can be modified with simple arithmetic
More flexibility
Better customization
38
What is the disadvantages of DSP?
Increased battery consumption
39
What are the two primary concepts involving DSP and what is the difference?
Sampling is about time information
Binary code/bits is about amplitude information
40
How does DSP work?
Acoustic signal is filtered through the analog anti-aliasing dilter and picked up by A/D converter
Acoustic signal is sampled periodically
Samples are converted to numbers via the electrical signal
Processing takes place through mathematical calculations to manipulate the digitized output
The numbers/digitized output is converted back to an acoustic signal
41
Sampling
This is how the A/D converter measures the signal amplitude at discrete points in time
The number of times per second a signal is sampled
If this is too low, information will be lost and a very low rate may add information that was not in the original waveform
42
Nyquist-Shannon theory
Sampling rate must be two times the highest frequency (Nyquist frequency) of the incoming signal
43
Aliasing
This is when false frequencies are represented and there is an incorrect processing of the signal
More low frequencies will be included then what was in. the input due to a low sampling rate
To find the aliased signal frequency = signal - sampling rate
44
Anti-aliasing filter
Placed before the analog-digital converter, input passes through a low pass filter
Frequencies above half the sampling rate are removed
45
Over-sampling
The sampling rate is at a frequency that is more than twice the Nyquist
Advantages- increases dynamic range and reduced noise
Disadvantages- greater power consumption and delays
46
Bits
The greater number of bits will result in better digital approximation of the signal
Too few bits may result in a rounding of the signal which equals noise (quantization error)
47
Quantization error
Difference between the actual analog signal and the digital representation resulting from rounding off numbers
In HA, this may be random noise, harmonic distortion and high frequency splatter
To avoid this use a higher bit rate
48
Quantization
Process of mapping input values in smaller set, often with a finite number of elements
Assigning binary values to analog signal
This is what gives a representation of an analog signal
49
Digital-to-digital converter
Takes many bits for a specified sample and changes it to a series of single bits
This has a higher sampling rare than an analog to digital converter
Smooths the output waveform for the receiver to process the voltage back into an acoustic signal
This is part of the digital-to-analog converter
A DAC may smooth by removing harmonics above the Nyquist
50
Two types of converters
Traditional- usually use the minimum sampling frequency which reduces power consumption
Modern- allows for improved dynamic range and increased frequency response
51
Overview of the fitting process
Testing
Communication/lifestyle assessment
HA selection
HA fitting
Verification
Patient orientation
Follow up appointment and validation
52
Is your fitting effective?
Provided audibility of speech and environmental sounds
Not over-amplified sounds to the point of patient discomfort
Tailored the programming according to the patients age, listening experience, length of auditory deprivation, loudness tolerance
53
Verification methods
Soundfield measures (functional gain/aided audiogram, aided speech testing)- subjective
Real ear measures- objective
Test box/coupler measures- objective
Asking the patient (subjective)
54
Functional gain- aided audiogram
An attempt to verify the response of the hearing aid in a frequency specific fashion
Most common form of verification
Will show up on an audio as an A
Limitation of this is that it is aided so it is the absolute threshold when gain is in place
Difference measure between soundfield thresholds in the aided and unaided condition
Want aided thresholds to be as normal as possible
55
How is functional gain of an aided audio measured?
Obtain soundfield threshold in a booth at the frequencies of interest without HA in place
500, 1000, 2000, 3000, 4000, maybe 6000
Obtain sound field measures in identical environment with HA in place and active and use a warble tone as it is better than pure
56
Benefits of functional gain aided audio
Involves the entire auditory system
Relies on behavioral responses
Intuitive for patients to understand
Easy to administer for clinician
Cheap- no special equipment
Only option for CI, ME implants and BAHA
57
Limitations of functional gain aided audio
Typically only performed at one input level
Frequency/amplitude resolution is fairly broad compared to probe-microphone measures
Aided thresholds are often invalid for normal and near normal thresholds
Aided thresholds are often binaural (will not be able to tell which ear is responding unless masking is present)
58
Differences between amplification and gain
Amplification- sound was made louder
Gain- a comparison of the input versus the output; difference between what comes in and what went out
59
Aided speech testing
Complete speech discrimination testing with the hearing aids in place using a soundfield speaker
Can also compare a speech measurement in the unaided condition to an aided condition (recommended using soft or conversational speech levels)
Aided speech testing is very intuitive for the patient
60
Overview of a proper fitting
Calibrate verification system
Otoscopy and probe mic placement
HA placed over probe mic (inside the ear)
Select prescriptive formula/rationale on verification system
Run specific types of stimuli and record what the HA is doing in the ear
Adjust gain in the manufacturer software
Re-run stimuli and keep adjusting until the targets are met
61
Real ear measures
Measuring sound rom inside the ear canal
Requires a probe mic at the level of the eardrum
Provide accurate, real-time response of sound in the ear
Frequency and gain specific with good resolution
62
Types of real ear measures
Response- a measure of absolute SPL in the ear canal
Gain- a difference/comparison measure (an output response expressed relative to the input signal or a reference response)
63
Real ear aided response (REAR)
Measuring sound from inside the ear canal with the hearing aid in the ear and turned on
64
Real ear aided gain (REAG)
REAR minus the input signal as measured at the reference mic; difference between an aided sound measured in the ear canal versus a sound measured at the reference mic
65
REIG
SLP at eardrum when aided minus SPL at eardrum when unaided
Takes into account natural amplification from the ear canal
Involves measuring the REAG and REUG, or REAR and REUR
66
Why do probe tubes need to be calibrated?
The tubes resonate and since they have their own resonance properties it needs to be taken into account
67
Visually assisted positioning
Use otoscope to check depth
Probe tube should be 4-6mm from the TM
68
Acoustically assisted positioning
Use REUG measures on the verification system to monitor placement
This is a more advanced technique where you need to know the normal resonance values
69
Average length method
Move collar to average length based on gender and age
28-30 for males, 26-28 for females, 20-25 for children
70
Geometric positioning
Measure alongside earmold/dome and add 5mm, move collar to match, and insert probe until the marker is at the inter-tragal notch
71
Bump and pull
extend the probe tube into the ear gently and slowly until the end touches the erdrum and then back it up slightly
72
Audioscan probe guide
Once the probe mic has been placed, can cross check the depth using an automated guide within the Verifit 2
73
What happens when the probe tube is not deep enough?
As the tube gets farther from the TM, will get weird standing waves and will impact high frequencies
74
Real ear unaided gain (REUG)
The difference between a sound measured in the unoccluded ear canal versus the sound measured at the reference mic
75
What is RECD?
Real ear dial difference
Correction factor for ear canal resonance
Difference between the intensity setting in HL on the audiometer dial and the output in the ear canal
Very common in pediatrics and sometimes for adults
RETSPL + RECD - REDD
Get a threshold in HL, need to convert this to SPL so use the RETSPL conversion then use a 2-cc coupler for the RECD conversion then you will have dB SPL in the ear canal
2-cc coupler was created to mimic the resonance of an empty ear canal, so that the hearing aid fitting could be stimulated in the test box
Usually a positive number- the output of the true ear canal is greater than the output of the coupler (the smaller the ear canal the larger the RECD)
RECD measured with foam tip is not the same as RECD measured with an earmold (earmold tubing is longer resulting in high frequency roll off)
76
Speechmapping
Verifit automatically converts the dB HL to dB SPL using average REDD
If a measured RECD is not provided, the system also uses an average RECD
Measuring RECDs will recalculate the thresholds and also the associated prescriptive targets
77
How to measure RECD?
1. calibrate the RECD transducer (verifit 1- RECD transducer attached to HA2 coupler; verifit 2- WRECD transducer attached to TRIC adaptor and silver 0.4cc coupler)
2. on verifit, select the coupling that will be used for the on-ear RECD measurement: either foam tip or earmold (need to use the same coupler from original hearing test)
3. position patient in front of verifit and place probe tube
4. attach RECD transducer to foam tip or earmold and place in ear canal over the probe tube (select foam tip that fully expands in ear and fits deeply)
5. Measure the RECDD/WRECD (two pairs of curves will be generated; top pair will be response of RECD transducer in the coupler (1) and response in the real ear (2), bottom pair is the difference between the upper curves (3) and age-appropriate average for reference (4))
6. adjust gain in manufacturer software to meet prescriptive targets (verifit will incorporate the RECD and recalculate the displayed thresholds in dB SPL and then recalculate the targets generated from those thresholds)
78
What will happen if there is shallow probe tube placement?
Negative high frequency RECD
Rolloff
79
What will happen if the probe tube is blocked or crimped?
Significant negative RECD values across the spectrum
80
RECDs with PE tubes/perfs
Extra volume will alter the resonance of low frequencies
Negative RECD values because the ME space is being included
81
RECD with verifit 1 versus 2
1- uses a 2cc coupler (HA1 for mold and HA2 for BTE), uses old ANSI standards
2- uses 0.4cc coupler, WRECD to reflect expanded bandwidth of modern hearing aids
82
What about open fits?
RECDs assume little to no venting (will lose venting if using a test box)
Stimulated REM for an open fit will be inaccurate so use the persons ear to account for loss of the low frequencies
83
Why aren't RECDs standard for adults?
Less likely to be using simulated for adults
Adult ears do not vary as much as children when compared to a 2-cc coupler standard
Some clinicians recommend RECDs to ensure proper correction of the LDLs thresholds during speechmapping not just the pure tone threshold
Remote fitting of devices and pandemic measures would make adult RECDs more useful, as patient contact is limited
84
When not to use RECDs
RECD not applied to audiometric thresholds measured with TDH or soundfield
S-REM (simulated REM) with very open venting
For adults, prioritize REAR/speechmapping in all cases if time is limited
85
Stimuli considerations for speechmapping
Test stimuli used should be compatible with the hearing aid it is testing
If it is a pure tone: a linear HA should produce similar results to noise signals, applied amount of gain is the same; non-linear HA results may differ depending on the stimulus signal; not recommended for REM as they are very suscpetible to reflections
Speech (excellent for WDRC): most important input signal, interacts with multi-band compressors in a more realistic way than tones, should interact appropriately with signal processing featuring such as feedback management and noise reduction
Broad-band stimuli: may differ greatly in spectrum, amplitude (overall level), bandwidth and spectrum, measurement time windows and other aspects of analysis also affect the results
Narrow-band stimuli: may not be accurate for non-linear HA
Speech-like noise: similar to white noise but includes speech frequencies
International speech test signal (ISTS)
International collegium of rehab audiology (ICRA)
86
International speech test signal (ISTS)
Composition of spliced 500ms segments of 6 female talkers
Includes multiple languages- American English, Chinese, French, Arabic, German and Spanish
Put together in such a way to include pauses like real speech, modulation
More acceptable for use internationally
87
International collegium if rehab audiology (ICRA)
Provide a selection of speech-like noise signal that could be used as background noise for hearing aid clinical testing and potentially measurement
88
Insertion gain
Stimulus dependent and the dependency is specific to each HA
Not recommended to fit a HA with this
Not great for non-linear HA
89
Speechmap measures (verifit)
Measures amplification from within the ear canal using recorded speech
Test stimuli include a choice of test signals
Can run stimuli at several different loudness levels
In on-ear mode, the MPO run is a sequence of 85 tone bursts at 1/3 octave frequencies
A variety of prescriptive formula are available and auto-generated
90
Long term average speech spectrum (LTASS)
Every speech sample played has own LTASS
Type of REAR (real ear aided response)
91
SII
The higher the number the better
Shows what percent of English phonemes are audible
92
Evaluative approach
Patient would wear one aid and then compare speech discrimination performance to a second (or third)
Not particularly scientific although hearing aids were also a lot simpler then in terms of features and programming
93
Prescriptive approach
A calculation of desired amplification characteristics using a prescription
An early example is the half-gain rule (prescribed gain = half the threshold)
94
Core assumptions of prescriptive strategies
Audibility of speech sounds is critical (bandwidth needs to be wide enough to amplify high frequency speech sounds, accounts for degree and configuration of HL)
Amplification for an individual with HL takes place within the constraints of his residual dynamic range
95
Loudness equalization
Equalized loudness across frequency bands results in higher speech intelligibility
Goal is to amplify speech sounds so that they are perceived as equally loud
Aims to normalize the perception of overall loudness
NAL: auditory system can only take in so much at once, less about audibility of all sounds, useful for postlingual adults
96
Loudness normalization
Assumes restoration of normal loudness perception will create better acceptance by the listener
The goal is to amplify speech sounds so that normal inter-frequency loudness relations are maintained
Low frequency vowels will get more loudness weight than high frequency consonants
97
DSL (desired sensation level)
Keep vowels loud
As much audibility as possible
Prescribe amplification such that the entire range of the acoustic signals is placed within the patients dynamic range
Uses loudness normalization
Audibility of speech is most important for learning languages
98
NAL
Prescription based on hearing thresholds
Goal is to maximize speech intelligibility while making sure overall loudness of speech at any level is perceived similar to a normal hearing person
Utilizes loudness equalization
99
NAL-NL2
Based on new evidence
Make loudness comfortable by carefully allocating gain at frequencies that can make a big contribution to intelligibility
Most common prescription for adults
Loudness model: applied to the amplified speech spectrum and compared to that of a normal hearing individuals loudness perception with the aim of optimizing intelligibility
Intelligibility model: not all frequencies equally important so a weighting is applied, with increased level distortion increases even for those without HL (level distortion), with HL we need louder for audibility but not so loud that we negatively affect intelligibility, as HL severity increases the effect worsens- desensitization (making the sounds louder does not mean better speech understanding for all hearing configurations)
Other factors: gender (females prefer 2 dB less gain), new users (initially prescribed less gain), higher compression ratios, steep losses, unilateral or bilateral fittings (NL2 applies less of a reduction in gain for bilateral fittings and it is level dependent), tonal language
100
Fig 6
A fitting formula that can be added to an array of other prescriptive formula
For low input levels, gain is prescribed with the goal of providing aided thresholds of 20 dB
Aided thresholds would then vary for more severe hearing loss
Requires adult patient who can provide a fair amount of feedback
101
Loudness-based procedures
Loudness based prescription requires that the clinician create an individualized loudness growth curve for each patient
May be good for people with severe sound sensitivity
102
Why does the verifit make that static noise right before the carrot passage?
Equalization process
103
Equalization process
The process of controlling the SPL as a function of a frequency at the field reference point
The field reference point is the location of sound inlet of reference mic during equalization
Communicates with the on-ear probe module to figure out how far away the patient is from the speaker
How far away the person is sitting will determine how loud the speech passage is played coming out the speaker
Open fittings (amplified sounds may escape the ear canal and be detected by the reference mic during the equalization process; reference mic thinks the additional sound is from the loudspeaker and the loudspeaker in turn adjusts the speech coming out of the speaker, need to mute HA first)
104
MPO
Counsel patients what to expect so they are not startled
Mute opposite ear in the fitting software so that patient is responding to the ear you are measuring
105
Consider ear canal acoustics
The response of a hearing aid in a real ear differs fro mthe same hearing aids repsonse in a 2cc-coupler
106
Why is REM so important with open fits?
Venting effects cannot be accounted for with RECDs
Venting will change the low frequencies and RECDs will not catch this so need to do REM
Keep in mind, an open fit may also be defined as a dome thats too small for the ear canal, dome may be closed but sound still leaking around it
107
Manufacturer software
Represents gain at different frequencies and inputs using estimated values
These numbers have a meaning relative to each other, a larger number means there is more gain at the frequency
108
What percent of audiologists claim that they use NAL or DSL?
78%
109
What percent of audiologists use verification?
44% but routinely maybe 25%
110
Manufacturer vs. NAL-NL2
Manufacturers fittings are usually "first fit" so there is reduced gain for soft input levels, roll-off above 2000 Hz, boost in the mid frequencies, more linear than prescribed
111
Initial fit vs. NAL-NL1
Verified prescriptions were within 4-5dB of target
Initial fit had poorer matches and were significantly different
112
First fit objective summary
The HA manufacturer is most interested in initial accpetance of HA sound quality and loudness
This usually results in under-amplifying high frequencies espcially for soft inputs
Overall gain may also be reduced
These are not terrible objectives but the audiologist needs to have full control on what the patient is hearing and then adjust accordingly
113
What are the two recommendations from the AAA task force and explain?
Gain verification- prescribed gain from a validated prescriptive method should be verified using a probe mic approach that is references to the ear canal SPL
Output verification- given the importance of avoiding excessive hearing aid output, maximum hearing aid output (OSPL90) verification is recommended to ensure that it does not exceed the patients threshold of discomfort
114
Why is uptake of REM so slow?
-REM takes too much time
-inserting a probe mic to the TM is uncomfortable or painful for the patient
-the equipment is expensive and the cost is not justified
-the HA should be adjusted in response to client comments even if the target is initially met so why spend time adjsuting the HA to match a target that you will immediately move away from
-insertion of the probe tube may cause feedback
-with tight earmolds your probe tube may be squashed
-accurate placement is difficult
the advanced features currently available make REM less worthwhile, device is so dynamic this measurement does not help
-audiology operating largely outside of mainstream reimbursement channels when it come to HA dispensing
-audiology is often in an employee role where lack of reimbursement for these aspects of patient care makes it difficult to argue for additional equipment
-lack of quality control of clinical training sites when audiologists are in training
-laziness
115
Where is the money going to come from to pay for REM?
REM with live speechmapping reduced the number of follow up tweaking appointments
Less return for credit (RFC)
116
How did the HCC achieve such a low RFC rate?
Individually measured LDLs
FCA
Realistic expectation
Encourage participation in our AR groups
117
What can the use of REM improve?
Sales, patient confidence and satisfaction, RFC, the financial health of the business
118
When do we repeat REM?
Suspect something is wrong with the HA or continued patient complaints
Change in hearing
PJ says every 2-3 years even with stable hearing (output of aids may be totally different then what you thought; a few years of minor changes can add up to a fitting nowhere near prescription)
119
Automatic fine tuning
IMC- inter-module communication
The fitting module can "see" what the verification device has recorded and auto adjust programming software
Automated adjustment of gain parameters to meet your chosen prescription
120
Oticon REM autofit
IMA between NOAh and the audioscan verifit 2 allows the manufacturer software to fit the hearing aid to targets in a few minutes
121
Explaining REM to patients
Easy to confuse patients with professional jargon
Keep it simple, unless patient asks for more explanation
122
Simulated REM
HA can be placed in the test box and fit to a prescriptive target using simulated REM or S-REM
Switch verifit screen to test box to speechmapping
Enter real-ear to coupler difference (RECD) measurement for most accurate fitting, otherwise use average values
For verifit 2, need to use specific S-REM test box setup and couplers
Run speechmapping curves at various intensities and match prescriptive targets the same as on ear procedure
123
Pediatric fitting overview
REM is non-negotiable
Small children will not sit still during speechmappping so the clinician will take a snapshot of the childs ear canal resonance and then apply that measurement to the fitting
Need to re-measure the RECD as the child grows
Need to use a prescriptive rationale designed for language learning and audibility
