Upload
others
View
0
Download
0
Embed Size (px)
Citation preview
Building Practice Success Through
Speechmap Real Ear Measurements
Chris Stokes-Rees
Speaker Disclosure
Relevant financial relationships:
• Audioscan
(Applications Specialist)
• Conestoga College, Kitchener Ontario
(professor, H.I.S. program)
Today’s Agenda
1. REM in a changing landscape
2. UNT study: perceived value of REM
3. Speechmap: review of the basics
4. Speech Intelligibility
5. Live Speech in counselling
6. RIC/RITE and an Open Canal Update
7. RECD: not just for kids anymore
8. Frequency Lowering
9. Simultaneous binaural REM
Real Ear Measurements
in a changing landscape
Evolving Hearing Aid Supply Chain Model
Smriga, D. “Who are we really working for?” presentation at ADA 2014
Evolving Product and Service
Delivery
Expected to…
• Provide improved access to hearing
aids
• Offer lower cost alternatives than
historically available
• Shift focus towards the product as the
solution
How to address ‘product focus’ and
highlight our relevance?
Verification Services
“Real-ear measurement”
Source: Hearing Journal Vol 59 No.4 Apr 2006
Are we conducting REM?
Are we conducting REM?
Mueller and Picou. Use of real-ear probe microphone measures. Hearing Journal, May, 2010.
Some Reasons for NOT using REMs…
• “Too time consuming”
• “Too difficult”
• “Too expensive”
• “You can’t verify X, Y or Z instrument.”
• “Measuring RECD and entering it in our software will guarantee your fitting is right.”
• “Doesn’t make a difference”
“We cannot know what a hearing aid does unless it’s performance is
measured”
Harvey Dillon, NAL Australia
NAL-NL2 REAR Results Using 5 Different Manufacturers’ Programming Software
Sanders, J., Stoody, T., Weber, J., Mueller, H., “Manufacturers’ NAL-NL2 Fittings Fail Real Ear Verification” Hearing Review, March 2015; 21(3): 24-32
55dB
N = 16
65dB 75dB
NAL-NL2 Comparison to 5 Different
Manufacturers’ Proprietary Fittings
Sanders, J., Stoody, T., Weber, J., Mueller, H., “Manufacturers’ NAL-NL2 Fittings Fail Real Ear Verification” Hearing Review, March 2015; 21(3): 24-32
55dB 65dB 75dB
N = 16
The Importance of Audibility
• A 10 year old set of analog hearing aids verified to NAL-R prescriptive targets outperformed the six largest manufacturers’ premium BTE hearing aids programmed to the manufacturer ‘first fit’ in speech-in-noise testing
• After being verified to NAL-R prescriptive targets 5 of the 6 premium digital hearing aids outperformed the 10 year old analog hearing aids
Leavitt, R. J., & Flexer, C. (2012, December 01). The Importance of Audibility in Successful Amplification of Hearing Loss. Retrieved from http://www.hearingreview.com/2012/12/the-importance-of-audibility-in-successful-amplification-of-hearing-loss/
Takeaways
• Selecting a target in programming software does not guarantee that targeted performance will be delivered in the patient’s ear.
• Differences can be substantial and unpredictable.
• The only way to KNOW what you are delivering is through verification measurements.
REM and Patient Satisfaction
82
23
79
32
51
58
6
53
7
31
0 20 40 60 80 100
Measure LDL
Measure Customer Satisfaction
Measure Objective Benefit
Measure Subjective Benefit
REM
Percent of Patients
Below Average Success Above Average Success
Adapted from Kochkin et. al. MarkeTrak VIII: The Impact of the Hearing Healthcare Professional on Hearing Aid User Success". Hearing Review, April 2010.
Perceived Value of REM
The Amlani et al UNT study, 2016
Impact of REM on perception of
hearing aid services
• Study in 2016 at UNT looked at the impact
of REM on the perceived value of service
received
• This unique study very relevant to address
the service vs. product question in hearing
aid delivery
Participants
• 60 subjects, bilateral mild-to-moderate
SNHL
Group 1: “Experienced” users (> 8hrs/d)
Group 2: “In The Drawer” users (< 8hrs/wk)
Group 3: “First-time” users (never tried)
The surveys used
1. WTP (Willingness to pay)
– One-item question indicating maximum dollar
amount individual willing to exchange to
obtain a service or product
2. SERVAL (Perceived Value of service)
– 14-item scale that measures attitude and
behavior toward perceived value
Procedure
• All groups divided into REM and QuickFit
paths.
• Exp and ITD groups given pre-surveys, all
three groups given post-surveys.
• Those on QuickFit path, given post-study
REM and one more survey.
Results - Willingness-to-pay
Results - Loyalty
e.g., “What is the likelihood that you would recommend this provider to family and friends?”
Results - Loyalty
e.g., “What is the likelihood that you would expand your purchase of additional services offered by this provider?”
Results - PERVAL
e.g., “The quality of the service I received was outstanding.”
Results - PERVAL
e.g., “The service provided eases anxiety about how well the product will work..”
Results - PERVAL
e.g., “The overall value of this experience was high.”
Why all this matters?
• Satisfaction of hearing aid users can be
linked to the type of verification services
offered
• Improves perceived benefit and
satisfaction with practicioner
• REM deemed a worthwhile expense
Speechmap
A quick review
The Speechmap Screen UCL (SPL, estimated from threshold)
SPL Threshold (converted from HL)
MAP(Minimum Audible Pressure)
Speech display & analysis
• Percentile analysis used to display the dynamic range of amplified speech.
Maximum levels (peaks or 99th percentile)
Average levels (L.T.A.S.S.)
Minimum levels (valleys or 30th percentile)
• Speech must be analyzed over a period of
ten seconds minimum.
• Prescriptive targets will be shown for the
long term average (L.T.A.S.S.)
Speech display & analysis
The counselling challenge…
Explaining
recruitment!
Use the Speechmap screen:
“Normal” dynamic range
“Reduced” dynamic range
Audiometric Data Entry
Soft Speech
Conversational Speech
MPO
SII
What is it and how can it help me?
Speech Intelligibility Index
• ANSI S3.5-1997 “Methods for Calculation of the Speech Intelligibility Index”
• Gives a numeric quantity that predicts
how much of the speech is audible
– in a graphic sense: how much of the
amplified speech area appears above SPL
threshold
• Unrelated to target formula
Soft Speech
Conversational Speech
SII vs. Predicted CST Score
(from Sherbecoe and Studebaker 2003)
Live Speech
as a counselling tool
Live speech as a counselling tool
• Live speech does not provide an effective,
repeatable test for fitting hearing
instruments.
However, it is a great tool in patient
counselling situations.
Average speech
Spouse’s voice
Compared
RIC/RITE and OC update
RIC dominates the market
http://hearinghealthmatters.org/waynesworld/2016/major-hearing-aid-disruption/
Vent effects on HI Gain
Dome type examples
Common OC mistakes
• Assuming that RIC = Open Canal
• Assuming that a closed dome is 100%
closed
• Attempting to match low frequency targets,
or provide LF gain where more occluding
coupling may be required.
Audiogram entered
Audiogram entered
Step 1: HI present but ‘off’
Step 2: HI turned ‘on’
Comparison
Difference between curves shows amplification reaching TM
How to determine candidacy
1. Position probe tube in ear
2. Enter audiogram and select a fitting
rationale
3. Run 65dB Speech with open ear (i.e.
REUR)
4. Compare LTASS curve with targets in the
sub-1kHz range
First audiogram entered
A good candidate for OC fit!
Second audiogram entered
Not recommended
RECD:
Not just for kids anymore!
RECD – what it is
• Real Ear to Coupler Difference
• Broadband signal measured in coupler
and in ear canal. RECD = difference in
output, across frequencies.
RECD – How it is measured
Frequencies at which
RECD was measured
Measured RECD values
Coupler mic
RECD transducer
RECD transducer
Probe mic
RECD – How it is used
1. Test box verification.
– AKA “S-REM”
– Speechmap simulated in a coupler, in the test
box
Isn’t this primarily
used in pediatric
fittings?
RECD – How it is used
2. HL Threshold correction.
– Used in the HL-to-SPL transformation
– More accurate SPL thresholds
Applicable to any
ear canal that is
not average!
Correcting Thresholds
• When we measure hearing thresholds the audiometer produces a stimulus in the ear
• The actual level in the ear is affected by the acoustics of the ear canal.
• The audiometer is calibrated to an average adult ear...for any other canal the actual threshold measured will be different
• RECD lets us capture what this difference is!
Correcting Thresholds
• Approximately 80% of adult ears exhibit average RECD
• Pro tip: watch for that 20%! When verifying fit on non-average ear canal, measure HL with inserts and use RECD!
Example case
Speechmap test: average RECD
RECD: 3 3 3 3 7 8 10 15 15 11
Speechmap test: entered RECD
RECD: 3 2 3 5 5 8 5 7 11 8
Note On Audiogram Correction...
• There are a number of ways clinicians use to measure the hearing thresholds (audiogram) including:
insert phones headphones sound field speakers
• RECD can only be used to correct the threshold values if the
patient’s thresholds were measured with insert phones
Frequency Lowering
How to adjust for optimal benefit
Freq. Lowering - The Concept
• Some hearing losses have un-aidable
regions where important speech
information exists
• Re-positioning input energy in these
regions to regions that are aidable can
provide access to these important speech
cues e.g. steep sloping HF losses!
Frequency Lowering Today
• In 2017 all high-end hearing instruments
contain this technology!
• Some manufacturers default it to “on” with
default settings.
• To provide best effect it should be adjusted
using the latest protocol.
The ‘s’ and ‘sh’ Stimuli
“S” @ 65dB
“SH” @ 65dB
• Special stimuli for use in adjusting frequency lowering function.
• Developed at University of Western Ontario.
FL Adjustment protocol
1. Run 65dB speech
2. Identify the Maximum Audible Output
Frequency range.
MAOF
Identify MAOF;
Where SPL
threshold crosses
LTASS and where
it crosses PEAK.
MAOF Highlighter
3. Run /s/ stimulus. Adjust so upper
shoulder of /s/ is within the MAOF.
MAOF Highlighter
4. Run /sh/ and check that it does not totally
overlap /s/ signal. Adjust if necessary.
MAOF Highlighter
On Verifit2, activate MAOF highlighter.
1. Run 65 dB speech test
MAOF Highlighter
2. Run /s/ in a separate test. From test
setup in /s/ test, select the test containing
65dB speech.
MAOF Highlighter
MAOF (i.e. target range) highlighted:
MAOF Highlighter
3. Adjust frequency lowering of instrument
so upper shoulder of /s/ is within MAOF.
MAOF Highlighter
4. Run /sh/ and fine-tune if necessary.
FL adjustment tip
• Ideal setting is always the LEAST amount
of frequency lowering that is required to
set the upper shoulder of the /s/ in the
MAOF range.
Simultaneous Binaural
A quick update & tips
Simultaneous binaural Speechmap
• Aids in efficiency and allows verification of
binaural functioning
• Provided in a number of manufacturers’
probe tube systems today
• Equalization at two ears is a challenge
Simultaneous binaural on-ear
• The issue: on-ear soundfield typically non-
symmetrical and uncontrolled
vs.
Simultaneous REM solutions?
• It is not possible to equalize a stimulus in level and spectrum at two places (i.e. each ear) at once.
• Solutions employed currently in the market:
– Average the error
– Select one reference mic (left or right)
– Force sequential measurement
– Provide tool for ideal patient positioning
Points to remember
• The Verifit Binaural Sound Field Assist and
the forced sequential binaural will only
activate if the stimulus at both ears is
>2dB different
• If sound field is even, simultaneous
binaural measurements will proceed with
no user interaction.
Tips for simultaneous binaural
• A good acoustic space is helpful... Keep
away from reflective surfaces
• Patient-to-speaker distance is key... Keep
under 60cm (2 feet).
• Binaural Sound Field Assist is sensitive to
external noises. As with any real ear
measurements, keep room silent.
Also: [email protected]