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Hearing Aid Fitting

Introduction
The Real Ear to Coupler Difference (RECD) is a measurement that accounts for the decibel difference across frequencies between SPL measured in the coupler and the SPL measure in the real ear, produced by the same transducer generating the same signal. This ensures that information about the patient’s occluded ear canal characteristics is obtained.

Due to the physically smaller size of the ear canals for infants and children compared to adults, and because it would be very difficult to do real-ear verification on them, the RECD is an important measurement in the pediatric hearing aid fitting process. It enables clinicians to verify the frequency/gain characteristics of the child’s hearing aid while it is attached to the 2cc BTE coupler, without the need to have the child’s ear physically present. Since children have physically smaller ears than adults, and smaller ears equals higher SPL, not taking the RECD into account would likely lead to over-amplification. For more information on RECD and the recommended guidelines for pediatric hearing aid fittings, please refer to the references at the end of this document.

Measuring the RECD
There are two ways of measuring the RECD: with the patient’s ear mould or with the SPL60 RECD probe tip.
Measuring with ear moulds will be a bit more precise than measuring with the SPL probe, however; in situations where a quick measurement is needed, using the SPL probe will be much quicker than measuring with the ear mould. In situations where no measurement can be obtained, it is recommended to use age appropriate, predicted RECD values. Instructions for all three methods are detailed below.

RECD measurement with earmold
Items required:

  • The Affinity 2.0 or Callisto™ with Coupler Base
  • The REM440 software
  • An REM headset/reference microphones
  • A probe tube
  • An ear mould
  • An RECD tube found in the SPL60 Probe tip set, which will be connected the ear mould tube via a tube-nipple
  • 2 cc coupler connected to an adaptor for the BTE

Figure 1: Measuring the RECD with an ear mould with Affinity 2.0 and Callisto™.

  1. Launch the Affinity 2.0 or Callisto™ software from your patient management system, Noah or OtoAccess™ and click on the REM440 tab
  2. From the Protocols and Sessions drop down list, choose a protocol that includes the RECD (ex: Pediatric Aided Response)
  3. Connect the thicker RECD probe tube to the larger metal spout on the REM headset and connect the regular probe tube to the smaller metal spout
  4. Calibrate the probe tube by clicking the calibrate icon and selecting “Regular Probe”
  5. Connect a tube nipple to the other end of the RECD probe tube
  6. Connect the tube nipple to the BTE tubing attached to the 2cc BTE Adaptor
  7. Click on the RECD test and click start to measure the coupler portion of the RECD measurement
  8. Once the coupler measurement is done, the software will prompt to measure the ear portion of the RECD. Disconnect the tube nipple from the RECD probe tube and connected to the ear mould tubing
  9. Proceed with otoscopy, ensuring the ear canal is clear. Place the probe tube inside the patient’s ear and position the ear mould, connected to the RECD probe via tube nipple, in the ear canal
  10. Continue with the ear portion of the RECD. The two measurements will be on the screen and the difference will be calculated automatically
  11. The RECD can now be used for the hearing aid fitting. The RECD can be imported, if that feature is supported, manually into the hearing aid software. The fitting will be recalculated while taking the RECD into account1 . To view the RECD values, click on Table View
  12. To proceed with the hearing aid verification, click on the REAR button; the software will automatically go into the coupler mode and it will then be possible to proceed with the verification. The default fitting formula will be DSL v5 Pediatrics. Use the hearing aid software to fine tune the hearing aid and to ensure that the output is matching the DSL targets for soft, average, and loud, using a speech stimuli (like the ISTS). Measure the MPO to ensure that the output for loud sounds is not hitting the UCL.

RECD Measurement with SPL60 Probe
Needed items:

  • The Affinity 2.0 or Callisto™ with Coupler Base
  • The REM440 software
  • An REM headset/reference microphones
  • A probe tube
  • The SPL60 probe tip
  • Impedance probe tips
  • 2 cc coupler connected to an adaptor for the BTE

Figure 2: Measuring the RECD using the SPL probe with Affinity 2.0 (a) and Callisto™ (b)

  1. Launch the Affinity 2.0 or Callisto™ software from your patient management system, Noah or OtoAccess™ and click on the REM440 tab
  2. From the Protocols and Sessions drop down list, choose a protocol that includes the RECD (ex: Pediatric Aided Response)
  3. Click on RECD. Right click and select “Settings. A window will pop up and ensure the checkbox “use In Situ SPL probe” is ticked off. This will tell the software that the SPL60 probe is being used rather than the ear mould2
  4. Connect the SPL60 Probe tip to the REM headset; thicker tube to the larger metal spout, regular probe tube to the thinner metal spout
  5. Calibrate the SPL60 probe by clicking the calibrate icon and selecting “SPL Probe”
  6. Connect the RECD adaptor to the 2cc coupler and attach to the coupler microphone
  7. Click on the RECD test and click start to measure the coupler portion of the RECD measurement
  8. Once the coupler measurement is done, the software will prompt to measure the ear portion of the RECD. Remove the probe tip from the coupler.
  9. Proceed with otoscopy, ensuring the ear canal is clear. Select an appropriately-sized probe tip and place it in the patient’s ear
  10. Continue with the ear portion of the RECD. The two measurements will be on the screen and the difference will be calculated automatically

Using age appropriate predicted RECD values

If it is impossible to get an RECD measurement (ex: child is crying or uncooperative), it is recommended to use age appropriate predicted RECDs.

  1. Launch the Affinity 2.0 or Callisto™ software from your patient management system, Noah or OtoAccess™ and click on the REM440 tab
  2. From the Protocols and Sessions drop down list, choose a protocol that includes the RECD (ex: Pediatric Aided Response)
  3. Select RECD
  4. Right click on the RECD and select “Show Predicted Curve”. A window will pop up, asking to choose the age and to choose the type of prediction: “ear mould” or “tip”

Own Mould versus SPL Probe
Whether the RECD is performed using the client’s own ear mould or the SPL probe may have an effect on the result. The benefit of using the client’s own ear mould is that the measurement will reflect your client’s actual residual volume whereas the SPL probe only provides an estimate. However, you may be in a situation where the ear mould is nonexistent, broken, or has an extremely bad fit. Furthermore, you might need to conduct measurements on children not willing to co-operate. In these situations the SPL probe offers the benefit of easy probe placement and measurement.

Below, see two RECD measured in the same ear using the SPL probe and own ear mould respectively. Note: the differences between the two ways of measuring. As can be seen above the curve measured with the client’s own ear mould is below 0 in the low frequencies. This may be due to ear mould effects such as the tightness of the fit and venting and in the insertion depth of the SPL probe or ear mould.

Using the RECD in the hearing aid fitting
The RECD can now be used for the hearing aid fitting. The RECD can be imported, if that feature is supported, manually into the hearing aid software. The fitting will be recalculated while taking the RECD into account3. To view the RECD values, click on Table View.

To proceed with the hearing aid verification, click on the REAR button; the software will automatically go into the coupler mode and it will then be possible to proceed with the verification. The default fitting formula will be DSL v5 Pediatrics. Use the hearing aid software to fine tune the hearing aid and to ensure that the output is matching the DSL targets for soft, average, and loud, using a speech stimuli (like the ISTS). Measure the MPO to ensure that the output for loud sounds is not hitting the UCL.

Visible Speech Mapping can also be used for coupler based fittings. This can be done by choosing the Visible Speech Mapping in the REM module, rather than the REM440 module it self. Note that Visible Speech Mapping requires a separate license.

For more information, please consult the Affinity 2.0 Additional Info and Callisto™ Additional Info documents, available on our website www.interacoustics.com.


1Not all hearing aid manufacturers support RECD imports. Contact the hearing aid manufacturers if unsure.

2If always using the SPL probe rather than ear moulds, it is possible to create a protocol to ensure that the “Use the insitu SPL probe” option is always ticked off. For information on how to create protocols, please refer to the Instructions for Use or Additional Info manuals for Affinity 2.0 or Callisto™.

3Not all hearing aid manufacturers’ software support the import of RECDs. If unsure, check with the hearing aid manufacturer.

References
Bagatto MP. Optimizing your RECD measurements.The Hearing Journal 2001; 54: 32, 34-36.

Bagatto MP. The Essentials of Fitting Hearing Aids to Babies. Seminars in Hearing 2013; 34:1, 19-26

Bagatto MP (2007). Learning the Art to Apply the Science: Common Questions Related to Pediatric Hearing Instrument Fitting. 

McCreery, Ryan. RECD is a Reasonable Alternative to Real-Ear Verification. The Hearing Journal 2013; 66:7, 13-14. Munro, Kevin. Integrating the RECD into the Hearing Instrument Fitting Process.

Purdy, J and Sheila, T. (2008). Measuring RECD on a Young Child. 

December 2013

This Quick Guide is intended to give a brief explanation on how to fit CROS and BiCROS type hearing aids. The instructions in this guide have been adapted from the methods stated by Hayes (2006) and Pumford (2005), links to these articles are provided at the bottom of this document.

The following points of instruction apply to the whole of this document and will aid understanding as to what is being measured in the different conditions:

  • The probe microphone is always placed in the aidable or normal hearing ear, never in the unaidable ear.
  • The patient will move position so that the loudspeaker is within the range of -900 through 00 to +900 relative to the front of the client at different stages in the procedure. Images have been used below to aid your understanding of this.
  • The reference microphone is always located on the same side of the head as the loudspeaker.

CROS Hearing Aids

The objective of this measurement is to make signals from the unaidable side of the head sound the same as signals from the side of the better or normal hearing ear.

Dedicated protocols have been created for optimum application of this test, please speak to your local distributor to get and import these for use.

  1. Calibrate and insert both probe microphones.

  2. Measurement One: Measure the REUR/REUG of the best ear with the patient at 450 or 900 to the speaker.
    Note: The CROS system is not added to the ear at this point.

    Run the ‘Better Ear REUR/REUG’ Measurement. This should lead to a curve similar to below.

    Note: Make sure that if you run your first condition at 450 then the second condition should be at -450. This is also required for measurements run at 900. If this isn’t done then the measurement curves are not comparable.

  3. Measurement Two: Move the patient so that the loudspeaker and reference microphone are to the side of the unaidable ear (-450 or -900 relative to the poorer ear). Add the CROS system to your patients ear and turn it on. You must also enable the CROS setting in your Affinity/Equinox or Callisto Suite (shown in the image below).

    Note
    : You do not need to swap earside in order to perform this measurement, all measurements are performed to the same earside from the first measurement.
    Run the ‘CROS Response’ measurement.

    The CROS Setting is available in the following location of your Suite.

    This measurement should lead to a curve similar to the below.
  4. You now need to adjust your CROS system until the REAR/REIG from the second measurement overlaps the REUR/REUG from the first measurement. Imagine the first measurement to be your target in this scenario.

    Note:
    Probe microphone measurements cannot be applied to transcranial/bone-anchored CROS fittings.

BiCROS Hearing Aids

The objective of this test is similar to what has been shown above, however there is a hearing aid on the better ear for which we need to take consideration for.
The same dedicated protocol as used in the CROS instructions above is used for optimum application of this test, please speak to your local distributor to get and import these for use.

  1. Ensure you have already Fitted the hearing aid without the CROS features enabled to a suitable algorithm based on the patients scenario (i.e. NAL-NL1, NAL-NL2 or DSL).

  2. Calibrate and insert both probe microphones.

  3. Measurement One: Measure the REUR/REUG of the best ear with the patient at 450 or 900 to the speaker. Remember to ensure the hearing aid is inserted and enabled in this scenario.

    Run the ‘Better Ear REUR/REUG’ Measurement. This should lead to a curve similar to below.

    Note: Make sure that if you run your first condition at 450 then the second condition should also be at 450. This is also required for measurements run at 900. If this isn’t done then the measurement curves are not comparable.

  4. Measurement Two: Move the patient so that the loudspeaker and reference microphone are to the side of the unaidable ear (-450 or -900 relative to the poorer ear). Enable the CROS system and the CROS setting in your Affinity/Equinox or Callisto Suite.

    Note: You do not need to swap earside in order to perform this measurement, all measurements are performed to the same earside from the first measurement.
    Run the ‘CROS Response’ Measurement.

    The CROS Setting is available in the following location of your Suite.

    This measurement should lead to a curve similar to the below.
  5. You now need to adjust your CROS system until the REAR/REIG from the second measurement overlaps the REUR/REUG from the first measurement. Imagine the first measurement to be your target in this scenario.

    Note: Probe microphone measurements cannot be applied to transcranial/bone-anchored CROS fittings.

Further Reading
For more information on this topic then please see the following articles:

Hayes, D. (2006). A Practical Guide to CROS/BiCROS Fittings.
Pumford, J. (2005). Benefits of probe-mic measures with CROS/BiCROS fittings. 

May 2017

The purpose of this Quick Guide is to give clinicians a short introduction to Visible Speech Mapping during the hearing aid fitting process and patient counseling.

Introduction
Verification of the hearing aid fitting is a very important part of the fitting process. To try to make this process a bit easier, rather than using traditional real-ear measurements, hearing care professionals can use the Visible Speech Mapping modules in the Affinity 2.0 and Callisto™ suites. Visible Speech Mapping is an intuitive tool which helps hearing care professionals better explain the benefits of amplification.

Getting Started
Speech Mapping is a Real Ear Aided Response (REAR) measurement; therefore the same equipment that is needed for a REAR is also needed. To start, follow the steps below.

  1. Launch the Affinity 2.0 or Callisto™ Suite through your patient management system, NOAH, OtoAccess® orStandalone.
  2. Enter/Select an audiogram from NOAH or from the AUD module (if using Standalone). If no audiogram is entered or selected, no targets will be displayed.
  3. Launch the REM module by clicking on the REM tab.

Prepare the patient for REM

  1. Connect the REM headset to the Affinity 2.0 or Callisto™ hardware.
  2. Connect a probe tubes to the REM reference microphones.
  3. Click on the Tube Calibration button and follow the instructions on the screen.
  4. Position the patient approximately 0.5 meters from the REM loudspeaker.
  5. Perform otoscopy to ensure the ear canal is clear.
  6. Snap the REM headsets on the REM headband and place on patient’s ear.

Measurement Steps

Figure 1: the Visible Speech Mapping screen

  1. Choose the Visible Speech Mapping protocol from the drop down menu.
  2. Choose the appropriate options with in the Fitting Prescription Settings window, which will appear automatically when the Speech Mapping protocol is chosen:The fitting formula can also be changed by expanding the “advanced view” option (#2 above).
  1. To verify the fitting, select the ISTS signal (to use a calibrated speech-like signal for verification).
  2. Click on the Visible Speech Mapping button at the bottom left of the screen. If using an Open Fitting configuration, click on the “Calibrate for Open Fit” before proceeding with verification.1
  3. Click on the slider to adjust the input level of the ISTS signal; suggested start level is 65 dB SPL. Click START.
  4. Repeat step 5 using soft and loud levels; suggested levels are 50-55 dB SPL and 75-80 dB SPL, respectively.
  5. Change the Input signal to Warble Tone. Using the slider (Figure 1, number 5) to increase the level of the signal to 90. Click START to measure the MPO.

    Note: If choosing DSLv.5, the MPO targets will automatically appear, since the UCL thresholds are always predicted from the audiogram. If choosing NAL-NL1 or NAL-NL2, the UCL thresholds need to be entered in the audiogram screen for the MPO targets to be generated.

  6. Fine tune the hearing aid if necessary, to match the target. Use the On Top mode button minimize the REM screen and to bring it “on top” of the hearing aid manufacturer software.
  7. Counsel the patient, using the tools described below.

Counseling Elements in Visible Speech Mapping

 

The Speech Spectrum: used to counsel regarding audibility.

  • For example: showing the patient that soft sounds (lower line on image to the left) are below the thresholds could help counsel on expectations of hearing aid performance.

  • It could also help HCPs demonstrate the effects of fine tuning the HI.

 

Using Live Speech Mapping or Environmental sounds.

  • Select the “Live Voice” feature to demonstrate the effects, benefits and limits of amplification.

  • Use a whisper to show how the hearing aid reacts to it.

  • Ask the significant other to stand far away from the hearing instrument user and talk; this helps demonstrate some of the limits of the hearing instrument.

  • Play environmental sounds to demonstrate how they sound with the hearing aid.

 

Counseling overlays.

  • Use visuals to help explain the hearing loss to patients.

  • Adding visual information helps understanding of amplification and hearing loss.

  • Choose from “Familiar Sounds”examples, Phonemes and Speech Banana.

 

Unaided vs Aided.

  • Easily visually demonstrate the difference between unprocessed vs processed/amplified sound.

  • Can demonstrate the effect of adaptive hearing aid features.

    • Frequency Shifting.

    • Noise reduction.

 

Speech Intelligibility Index.
Use this to visibly show, using a percentage, improvement in speech intelligibility from unaided to aided.

 

Adaptive Feature example 1: Demonstrating Frequency Shifting.

  • Red curve: Unaided vs Aided, normal amplification.

  • Blue curve: Unaided vs Aided after activating a frequency shifting algorithm

 

Adaptive feature example 2: Demonstrating Noise Reduction.

  • Red Curve: Unaided and Aided with Noise Reduction feature OFF.

  • Blue Curve: Unaided and Aided with Noise Reduction feature set to MAX.

 

Dynamic range.

  • The dynamic range is the range between the softest sound the ear can detect and the loudest sound the ear can tolerate (thresholds and UCLs).

  • Use the Speech Mapping graph to explain the consequences and limitations of narrowed dynamic ranges.

  • Demonstrate the difference between a normal dynamic range (normal hearing to UCL) and a narrowed dynamic range (hearing loss to UCL).


1For instructions on how to do the open fitting calibration, please refer to the REM Quick Guide

December 2013

The purpose of this document is to provide a quick guide for the REM procedure stated by the British Society of Audiology (BSA) for the REM440 Real-Ear Measurement module in the Affinity2 and CallistoTM Suites. This Quick Guide will focus on the method and order of the REM measurements specified by this guideline.

Introduction
The BSA Clinical Practice Guidelines recommend using the NAL-NL1/NAL-NL2 fitting formulae when performing Adult hearing aid verification. The choice between the use of the REIG (insertion gain) or the REAR (aided response) is at the audiologists’ discretion as both methods are accepted verification methods. This Quick Guide assumes that the hearing aid has been programmed accordingly based on patients’ needs and hearing loss.

Preparation

  1. Enter/Select an audiogram from Noah or from the AUD module. If no audiogram is entered or selected, no targets will be displayed.
  2. Connect probe tubes to the REM reference microphones.
  3. Click on the Tube Calibration button  and follow the instructions on the screen, this process ensures that the probe tube is made acoustically invisible – enabling an effective display of the actual gain achieved at the tympanic membrane by the hearing aid.
  4. Position the patient approximately 0.5 meters from the REM loudspeaker.
  5. Perform otoscopy to ensure the ear canal is clear.
  6. Snap the REM headsets on the REM headband and place on patient’s ear.

Verification using Insertion Gain (REM Adult UK)

  1. Choose the REM Adult UK protocol, this is correctly configured according to the BSA Guidelines.
  2. Choose the appropriate options with in the Fitting Prescription Settings window, which will appear automatically when a REM protocol is chosen:

It is here that you will configure your prescription settings to acknowledge aspects of the patients amplification setup, i.e. venting, mono/binaural, compression method, whether you wish to base your target on their Bone values for mixed and conductive losses. etc.

  1. Select the desired verification signal.
    It is advised that a calibrated signal such as ISTS is applied. This ensures that the Long Term Average Speech Spectrum (LTASS) level is maintained and is known to provide consistent stimulation intensity throughout the duration of the measurement.
  2. Insert the probe tube in the patient’s ear without the hearing aid, you should aim to have this at a length of 27mm from the patients tragus, this ensures that the tube is close to the ear drum.
  3. Click on REUR, and click on START to measure the Real-Ear Unaided Response
    (Note: The REUR is a required measurement as it is used for the calculation of the REIG, it enables consideration for the patients’ natural ear canal resonance).
    Effective placement of the Probe Tube is achieved when the response is between 0dB and -5dB at 6kHz. Reposition the tube and re-perform the measure if you cannot achieve this, it will lead to improved measures.
  4. Place the hearing aid in the patient’s ear, but ensure that it is muted.
  5. Click on REOR and click on START to measure the Real-Ear Occluded Response. The REOR shows the occluding effect of the ear canal in relation to the patients’ natural ear resonance. It can also be used as an effective method of checking whether you are blocking the probe tube ahead of beginning your measurements.
  6. Measure the insertion gain at the desired input level.
  7. Fine tune the hearing aid if necessary. Use the On Top mode button  to minimize the REM screen and to bring it “on top” of the hearing aid manufacturer software.
    BSA guidelines advise that you begin at 65dB and then adjust softer (50dB) then louder (80dB) and finally re-check 65dB to ensure that amendment of the soft and loud trimmers haven’t drastically altered the response of this stimulus outside of the BSA recommended range.

Verification of Open Fittings (REM Adult Open Fit UK)

  1. Choose the REM Adult Open Fit UK protocol:
  2. Choose the appropriate options within the Fitting Prescription Settings window, which will appear automatically when a REM protocol is chosen.
  3. Select the desired verification signal.
  4. Insert the probe tube in the patient’s ear without the hearing aid.
  5. Click on REUR, and click on START to measure the Real-Ear Unaided Response 
    (NOTE: The REUR is a required measurement as it is used for the calculation of the REIG).
  6. Perform the Open Fit calibration:

Open Fit Calibration steps:

  1. Position the probe tube in the patient’s ear canal.
  2. Place the hearing aid, connected to the hearing aid fitting software, inside the patient’s ear.
  3. MUTE or SWITCH OFF the hearing aid.
  4. Choose the stimulus (ex: ISTS) and click on START to perform the calibration. The calibration values will now be stored inside the system and the reference mic will be turned off.
  5. UNMUTE the hearing aid
  6. Proceed with Real Ear Measurements.
    The purpose of this process is to ensure that the REM system is not actively regulating the output of the stimulus speaker. The reason why we want to disable this is because there is sound leakage from the Open Fitting onto the REM headset’s reference microphone. Therefore the stimulus delivered is inaccurate. By storing the distance from the speaker via this measurement the speaker can then stimulate according to that fixed point. It is important to ensure the patient maintains their position during this type of measurement.

Verification using the REAR protocol

  1. Choose the REM Adult Aided Response UK protocol:
  2. Choose the appropriate options with in the Fitting Prescription Settings window, which will appear automatically when a REM protocol is chosen:
  3. Select the verification signal.
  4. Measure the aided response for soft, average and loud
    (Note: with REAR measurements, it is not necessary to measure the REUG/REUR. However, some clinicians like to use the REUG/REUR as an indication for adequate probe placement.).
  5. Fine tune the hearing aid if necessary. Use the On Top mode button  to minimize the REM screen and to bring it “on top” of the hearing aid manufacturer software.

For a more detailed description of how to use the REM440 module, please refer to the following documents:

December 2013

Introduction
The purpose of this Quick Guide is to provide guidelines on how to conduct basic technical measurements of hearing instruments using the HIT440 module for the Interacoustics Affinity 2.0 hearing aid analyzer.

Note: Hearing instruments needs to be in FULL ON GAIN MODE/TEST MODE in order to compare the results to the hearing aid manufacturers’ technical data sheets. Each hearing aid manufacturer has a different way of accessing this Test Mode. Please check with the hearing aid manufacturers for instructions on how to program the hearing aid into TEST MODE.

  1. Launch the Affinity2 Suite from your patient management system, Noah or OtoAccessTM.
  2. Click on the HIT tab to launch the HIT440 module.
  3. If comparing to manufacturers’ technical specification, ensure that the hearing aid is in FULL ON GAIN MODE.

Setup 

BTE hearing instrument
Required Items:

  1. The Affinity 2.0 hardware.
  2. The Affinity 2.0 Suite with the HIT440 module.
  3. A coupler microphone.
  4. A coupler (most common is 2cc coupler).
  5. The BTE Adaptor for the coupler.
  6. The reference microphone 2 (included in Affinity 2.0 test box).
  7. Earmold Tubing to connect the hearing instrument to the BTE adaptor/coupler.

Positioning the BTE in the test chamber:
Place the coupler tube pointing straight forward and the microphone at the cross. (Multiple microphones: Place the half-way point between the microphones at the cross).

ITE/Open Fittings/Receiver in the ear
Required Items:

  1. The Affinity 2.0 hardware
  2. The HIT440 software.
  3. A coupler microphone.
  4. A coupler (usually 2cc).
  5. An ITE adaptor for 2cc coupler.
  6. A reference microphone.
  7. Blue putty to secure the hearing instrument to the 2cc coupler.

Positioning the ITE hearing instrument:
Place coupler at the back with hearing aid facing forward and the microphone at the cross. (For multiple microphones, rotate the hearing aid to get equal horizontal positioning of the mic inputs). Connect the ITE adaptor to the 2 cc coupler and attach the hearing aid using blue putty.
ITE pick-up coil test: For this particular test only: Position the coupler for maximum sensitivity of the coil.

Positioning the Open Fit/Receiver in the ear hearing instrument:
Connect the ITE adaptor to the 2 cc coupler. Remove the tip/dome from the hearing instrument and attach it to the ITE adaptor using the blue putty. Place the coupler tube pointing straight forward and the microphone at the cross.

Test procedure:

  1. Position the hearing aids and reference microphone as shown in the pictures above.
  2. Select the desired test protocol in the List of Protocol
  3. Select Test Ear.
  4. Select START

  5. Please wait for all tests of the selected protocol to be performed.
  6. Save by clicking “Save” icon

Comparing to the manufacturers specification sheets
Most hearing aid manufacturers use known international standards, such as the ANSI or IEC for their specification sheets. The same standard can usually be selected in the HIT440 software.

Testing for battery drain

  1. Insert the battery pill inside the hearing aid (example below).
  2. Connect the battery pill into the red socket in the Affinity 2.0
  3. If the test is included in the test sequence, it will be measured automatically.

For more information on HIT440, please refer to the Affinity 2.0 Additional Information document.

December 2013

The purpose of this document is to provide a quick guide for the Binaural REM feature found in the REM440 Real-Ear Measurement module in the Affinity 2.0 and Callisto™ Suites. This Quick Guide will focus on the method and order of performing measurements using this function.

Introduction
Interacoustics are pleased to announce the availability of a Binaural REM feature in the Affinity 2.0 and Callisto™ Suites. This feature will allow you to perform Real Ear Measures in a much faster procedure and allow you to view the activity in each ear simultaneously.

Preparation

  1. Enter/Select an audiogram from Noah or from the AUD module. If no audiogram is entered or selected, no targets will be displayed.

  2. To enable Binaural REM measurements in the REM module you will need to Right click on the ear selector icon. This will then show a binaural icon and a popup to alert the user when using this function.

    Due to the way in which this feature has been implemented you will not need to recreate new protocols to use this function. It uses the settings you already have in your existing protocols.

    Please note: when running measurements of this type you will only be using one reference microphone to monitor the signal from the speaker. This is the right microphone by default but it can be swapped to the left microphone by using the ‘use opposite reference microphone’ button. 

     

    It is also essential that the position of the patient in relation to the REM speaker is maintained at 0° as this will ensure that the same signal intensity is reaching each ear as they are equal distance from the speaker.

  3. Connect probe tubes to the REM reference microphones.

  4. Click on the Tube Calibration button  and follow the instructions on the screen, this process ensures that the probe tube is made acoustically invisible – enabling an effective display of the actual gain achieved at the tympanic membrane by the hearing aid.

    On running the calibration you will notice that in Binaural mode there is an automated procedure to calibrate both Left and Right REM tubes sequentially, without having to manually start each individually.

  5. Position the patient approximately 0.5 metres from the REM loudspeaker.

  6. Perform otoscopy to ensure the ear canal is clear.

  7. Snap the REM headsets on the REM headband and place on patient’s ear.

  8. Choose a relevant protocol to perform your verification; in this example the default ‘Adult Insertion Gain’ protocol has been used.

     

    Note: For this example, an Insertion Gain method has been used to demonstrate the Binaural REM feature, however the feature is also compatible with protocols which perform this measurement in an Aided Response method.

  9. Once you have chosen your protocol please configure your fitting prescription settings as per your fitting.

  10. Place the REM tubes inside the patient’s ears and aim to use a marker of roughly 27mm on the probe tubes. This helps to get the open end of the tube in an optimum recording position (BSA, 2007).

  11. Begin by running the REUR measurement, this is looking at the natural acoustics of your patients ear canals, it is performed with nothing in the patients ear canals apart from the probe tubes. Your response should peak around 2-3 kHz for a normal adult response (BSA, 2007). The shape of this measurement can also be used as a quality criteria for your probe placement, the measurement should intersect the

    Horizontal axis (x-axis) at 6khz and must not be more negative than -5dB (BSA, 2007 & ISO, 2003).

  12. You can now proceed to running the REIG measurements, there are 3 different intensity measurements in this protocol but the main focus should be to fit the 65dB curve as this is the intensity for speech. 

    Please place the hearing devices into your patient’s ears along with the probe tubes for the following measurements. 

    You will notice that there is a target in these measurements; in the next step it is shown how you can amend the output of the patient’s hearing devices to meet these targets.

    Note: the default view for the Binaural REM feature is to have the left and right aided measure displayed side-by-side. However this can be swapped to an on-top comparison by pressing the button shown below, there is an example of this view below.

     

    Note: Percentile analysis can also be performed in Binaural REM, you just need to enable this setting within your Aided Response measurements protocol. Once enabled, the test screen will show you the percentile range for your output, as shown below.

  13. You will now begin fine tuning in the hearing aid fitting software to amend the output of the device to meet the prescription target.
  14. Should you wish to edit the targets when performing a binaural measurement then you should click on this icon . Doing this will open the below dialogue screen which will allow you to edit the target for each independent ear currently on the screen or input your own, i.e. a proprietary target from a hearing aid fitting software.
     
    On setting a custom target it reverts the target to a ‘Custom target’ from a previously set standard target (NAL, DSL etc.) on doing this you should input values for both ears otherwise no target will appear for the side which you haven’t entered values for.

    Note: Using this feature will remove your previous target allocation (i.e. NAL-NL2, DSLmi/o etc) from the opposite ear side, which you have not provided custom values for, because we cannot allow different prescription methods to be used on different ears independently.

  15. A nice feature in the Affinity 2.0 and Callisto™ Suites is the On-top-mode. This feature allows you to minimize the suite so that it can be placed on top of the fitting software to make it easier to fine tune and compare the output following your changes. This feature can be used on pressing the following button on the left of the Suite GUI.
  16. Once you have fine-tuned your hearing devices so that the patient is happy and have counselled them involving their opinions in the amplification of their hearing devices you can save and close the Suite and finish the session. This is done by pressing the ‘Save and Exit’ button.

Note: Binaural REM can also be used when fitting Open Fit type hearing aids. All this requires is for the ‘Open Fit Calibration’ to be run following the REUR measurement for the signal(s) you wish to use for the following measurements.

Note: Binaural REM can only be used with stimuli which do not require active referencing during the measurement. Therefore Binaural REM is not suitable for measurement with Warble Tone, Pink Noise, Random Noise, Pure tone and Narrowband Noise.

For a more detailed description of how to use the REM440 module, please refer to the following documents:


References 
BSA (2007). Guidance on the use of Real Ear Measurement to verify the fitting of digital signal processing hearing aids. Reading, British Society of Audiology.

BS ISO 12124 (2001). Acoustics: Procedures for the Measurement of real-ear acoustical characteristics of hearing aids. Geneva, International Standards Organisation.

November 2015

The purpose of this Quick Guide is to describe how to do real-ear verification of Ear Level FM systems (Oticon Amigo Star, Phonak iSense) with the Interacoustics Affinity 2.01 Hearing Aid Analyzer, using FM-specific targets.
The verification method is based on the AAA Clinical Practice Guidelines for Remote Microphone Hearing Assistance Technologies for Children and Youth Birth to 21 Years. For more information, please refer to the AAA Guidelines.

Introduction
Ear Level FM systems are intended to be used by patients who have normal or near-normal hearing and help increase the signal to noise ratio. They can be used, for example, in classroom settings for a child having learning difficulties or auditory processing disorders (APD). Typical use will include an ear-level FM receiver, coupled to a thin tube, in an open ear configuration. The steps below guide clinicians on how to perform straightforward real-ear verification of the ear level FM system, in order to verify the maximum output and the recommended volume setting for the FM receiver.

Verification Steps

  1. Prepare the patient for normal real ear:
    • Position patient in front of the Affinity loudspeaker.
    • Place the probe tube in the ear.
    • Position the ear level FM receiver on the ear.
  1. From Noah or from the Affinity suite AUD screen, enter the audiogram. The audiogram will be within the range of normal/near normal.

  2. Click on the REM tab.

  3. Once in the REM screen, select the “Ear Level, FM only” protocol from the drop down list.

  4. Place the FM transmitter microphone inside the test chamber, facing the reference microphone.

    NOTE: The test box reference microphone is the active microphone

  5. Close the lid of the test chamber.

  6. Measure the MPO:
    • Click on MPO to access the MPO test.
    • Set the FM transmitter volume control to MAX.
    • Click Start to measure the Real-Ear Saturation Response.
    • If the MPO measurement is too high, adjust the FM output.


  7. Measure the REAR and match target between 1kHz and 4kHz.
    • Select the appropriate FM-specific target:
      • FM Boom or
      • FM Chest
      •  the choice should reflect what is used with the FM system being tested
    • Measure the REAR by clicking the Start button.
    • Adjust volume control on the FM receiver to match the targets between 1kHz and 4kHz. 
  8. Re-measure the RESR/MPO at user setting.


1Affinity software version 2.4 or higher is needed for Real Ear verification of ear level FM systems

References
American Academy of Audiology (April 2011). Clinical Practice Guidelines: Remote Microphone Hearing Assistance Technologies for Children and Youth Birth to 21 Years (includes supplement A). 

Angelo, Kamilla & Fuglholt, Merethe L. (2013). Amigo Star. A New Ear-Level FM-Only Receiver. Pediatric Knowlegdge Brief.
Eiten, Leisha R. FM for Children, Chapter 7. Assessing Open Ear Edulink Fittings.

December 2013

Introduction
The purpose of this Quick Guide is to describe how to verify FM transparency of FM system using the Interacoustics Affinity1 Hearing Aid Analyzer. FM Transparency can be defined as “The condition in which equal inputs to the FM and hearing aid microphones produce equal outputs from the hearing aid.”2 The verification method is according to the AAA Clinical Practice Guidelines for Remote Microphone Hearing Assistance Technologies for Children and Youth Birth to 21 Years. For more information, please refer to the AAA Guidelines.

The FM Transparency consists of 3 easy coupler measurements:

  1. Hearing Aid alone.
  2. Hearing Aid + FM receiver attached, FM transmitter on and muted .
  3. Hearing Aid + FM receiver attached. Transmitter microphone unmuted and positioned inside the test chamber, facing the reference mic. Hearing instrument still attached to the coupler/coupler mic, positioned outside the test chamber.

Verification Steps

  1. Launch the Affinity 2.02 Suite and choose a patient, through Noah or OtoAccess™.
  2. Launch the REM module.
  3. Select the FM Transparency protocol from the drop down menu.

NOTE: FM Transparency assumes that the hearing aid has already been programmed to match the targets, according to the patient’s hearing loss and patient needs. Therefore, there is no need to show targets on the screen. Targets and Fitting prescription information will not appear on the main screen when the FM transparency is chosen.

The FM Transparency setup guide will pop up when the above protocol is chosen, instructing the HCP on how to setup for FM Transparency verification3:

Step 1: HA Alone

  1. Select the HA Alone test.
  2. Attach the hearing aid to the coupler/coupler microphone.
  3. Position the hearing aid in the test chamber.
  4. Click START to measure the output of the hearing aid (red curve).

Step 2: HA + Receiver

  1. Leaving the hearing aid attached to the coupler, attach the FM receiver to the hearing aid.
  2. Turn on the FM transmitter. Mute it.
  3. Click START to measure the output of the hearing aid (purple curve). 


Note: the two curves should be very similar to each other

Step 3: FM Mic + HA

  1. Remove the hearing aid, still attached to the coupler, from the test box.
  2. Position the FM microphone inside the test box, in front of the reference microphone.
  3. Click START to measure the output of the hearing aid when input is from the FM microphone (green curve).


Note:

  • If a significant difference is already seen between the Green curve and the Red curve, one can presume that there is a problem with the FM microphone.
  • Ensure that the test is conducted in a quiet environment, since the hearing aid is outside the test box and the HA microphones are still active.

Step 4: Calculate the average difference

  1. Click on the table mode icon  to activate Table Mode.
  2. Once in table mode, calculate the difference between 750 Hz, 1000 Hz and 2000 Hz and
  3. Calculate the average.
  4. If the average is 2 dB or less, FM transparency is achieved.
  5. If the average is more than 2 dB, adjust the FM.

Example 1

*Average difference is less than 2 dB, therefore transparency is achieved

Example 2

*Average difference is less than 2 dB, therefore transparency is achieved


1To have access to the dedicated FM Transparency test, Affinity suite 2.4 or higher is needed.
2American Academy of Audiology (2011).
3The FM Transparency test is a coupler test, therefore the protocol will start up in coupler mode by default. Coupler mode is indicated by a hearing instrument attached to a coupler on the main screen.

References
American Academy of Audiology (April 2011). Clinical Practice Guidelines: Remote Microphone Hearing Assistance Technologies for Children and Youth Birth to 21 Years (includes supplement A). 

Fernée, Ben Zalm (2012). FM Verification Made Easy 

December 2013

This Quick Guide is indented to provide information on how to conduct directional testing of hearing aids, using the REM440 module of the Affinity 2.0 and Callisto™ Software Suites.

Directionality Test using REM440

Directionality Test using Real Ear Measurements

  1. From your patient management system, Noah or OtoAccess™, launch the Affinity 2.0 or Callisto™ suites.
  2. Launch the REM440 module by clicking on the REM tab.
  3. Prepare the patient for Real Ear Measures.
  4. Calibrate the probe tube.
  5. If fitting an open hearing instrument, perform Calibrate for open fit.
  6. Ensure that the correct Ear is selected.
  7. To activate the Directional Test, go to: Menu│Setup│Show/hide protocolsUSStandard Directionality. Insert the checkmark inside the box in front of Standard Directionality. This will ensure that the Directionality test is available from the list of protocols drop down menu1.
  8. Choose the preferred Stimulus in the corresponding dropdown list.
  9. Change the input level using the slider if desired.
  10. Click START and follow the instructions on screen.
  11. Place the client in front of the loudspeaker as shown on the picture. Click OK and front microphone curve will be recorded. New instructions will immediately appear. Turn the client around and click OK.

To add the directionality test to an existing protocol:

  1. Go to Menu │Setup │REM440 Setup.
  2. Choose a protocol to copy (ex: Adult Aided Response) from the drop down list.
  3. Click New to create a new protocol.
  4. Click Yes when the software asks if you want to copy the currently selected protocol2.
  5. Rename the Protocol.
  6. Add the Directionality test to the existing protocol.
  7. Edit the settings if desired by clicking on the Settings button.
  8. Adjust the Settings if desired.
     

1 If choosing US country defaults during the Affinity or Callisto software installation, the Directionality test will be available by default.

2 If selecting NO, you will have to create the protocol from scratch, which is beyond the scope of this document. For more info, please refer to the Instructions for Use document, Additional Info document or Quick Guide on Protocol Setup

December 2013
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