the fitting of hearing aids with in-situ measurementsinventis • audiology equipment trumpet rem...
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The fitting of hearing aids with in-situ measurements
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fitting in situ of hearing aids
definition
why to acquire them how to
acquire them
advantages
Inventis • Audiology Equipment
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REM • definition
• Real Ear Measurement
• objective and repeatable method
for quantifying the intensity of a
stimulus in the patient’s ear canal
definitionadvantages
why to acquire them how to
acquire them
Inventis • Audiology Equipment
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• to obtain the best configuration of the HA depending on
patient’s needs
• to avoid setting device’s gains based on average
population curves → prediction error
REM • why to acquire them
definitionadvantages
why to acquire them how to
acquire them
Inventis • Audiology Equipment
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HA1 HA2 HA3 HA5HA4 NAL-NL2
1.0
0.8
0.6
0.4
0.2
0.0
Spee
ch In
telli
gib
ility
Ind
ex
65 dB input75 dB input
55 dB input
Sanders et al, Hearing Review (2015)
REM • why to acquire them
comparison between five proprietary programming algorithms and the NAL-NL2 formula
the Speech Intelligibility Index is always higher in the case of NAL-NL2
Inventis • Audiology Equipment
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• visual demonstration of the benefits provided by
the device
• patient satisfaction
• significant reduction in the number of repeated
medical examinations
REM • advantages
definitionadvantages
why to acquire them how to
acquire them
Inventis • Audiology Equipment
7Inventis • Audiology Equipment
REM • how to acquire them
8Inventis • Audiology Equipment
what it doesvalid, repeatable and reliable method for assessingthe value of the sound in dB SPL to 3mm - 5 mm from the tympanic membrane
aim• to check the hearing aid performance, while it is
worn by the patient• to ensure that the sounds from the hearing aid
output are audible and comfortable
REM • how to acquire them
9Inventis • Audiology Equipment
how are they performed?
• speaker
• probe microphone placed at 3mm – 5mm from the eardrum
• reference microphone placed at the base of the pinna
• hearing aid
not inserted (UNAIDED)
inserted and turned off (OCCLUDED)
inserted and turned on (AIDED)reference
mic
probe mic
REM • how to acquire them
10Inventis • Audiology Equipment
free fieldspeaker
reference mic
probe mic
REM • how to acquire them
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measuring quantities at stake:
- how much does the patient’s ear canal amplify, naturally, without the hearing aid?
- how much does the insertion of a hearing aidocclude the patient’s ear canal, reducing the naturalamplification?
- how much does the hearing aid amplify sounds, after being inserted and switched on?
REM • how to acquire them
Inventis • Audiology Equipment
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NAL-RP
POGO II
POGO 1
1/2 Gain1/3 Gain
NAL-NL2NAL-NL1
DSL v.5
CAM2
algorithms aimed at determining a target amplification curve that represents the ideallistening level for the user of the HA
REM • fitting rules
Inventis • Audiology Equipment
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DSLDesired Sensation Level
NALNational Acoustic Laboratories
REM • fitting rules
Inventis • Audiology Equipment
14Inventis • Audiology Equipment
• verify the presence of earwax and exudate
• provide detailed information on the anatomy of the ear canal
• exclude the presence of problematic situations
preliminary tests • Otoscopy
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preliminary tests • Pure Tone Audiometry
earing threshold is the only mandatory input needed to calculate the target curve
audiometry starting point for estimating optimal gains to generate a certain sound intensity at the eardrum
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REM • preliminary procedures
17Inventis • Audiology Equipment
REM • preliminary procedures
❑ SPEAKER EQUALIZATION
AIM: sound that reaches patient’s ear is the same emitted by the loudspeaker
❑ PROBE TUBE CALIBRATION
AIM: make the microphone and probe tubes “acoustically invisible”
❑ PROBE TUBE PLACEMENT
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RE - real ear measuresacquired on the patient
A, I, O, U symbolizethe hearing aid state
R and G don’t provide info on the hearing aid state
RE U
OA
IG
RRESPONSE: value at probe
GAIN: difference between the valueat probe and reference
REM • how to acquire them
19Inventis • Audiology Equipment
Maestro software exam allows to perform the following test modalities:
• Standard acquisition mode (unaided, occluded, aided)
• MPO (Maximum Power Output)
• Advanced mode
• Live Speech mode (Speech Mapping)
REM • how to acquire them
20Inventis • Audiology Equipment
HA not inserted (UNAIDED)
REUG: real-ear unaided gain
• difference between dB SPL measured at the probe mic and dB SPL measured at the reference mic. Ear canal not occluded
• each software provides a predicted average REUG, e.g. kemar (→ estimate)
REUR: real-ear unaided response
dB SPL measured at the probe; ear canal not occluded
REUG
KEMAR
REM • Unaided Measurements
21Inventis • Audiology Equipment
HA inserted and turned off (OCCLUDED)
REOG: real-ear occluded gain
• difference between dB SPL measured at the probe
mic and dB SPL measured at the reference mic,
ear canal occluded, frequently negative
• useful to evaluate the effectiveness of any vents in the ear mold, applied to allow certain frequencies
to enter the canal
REOR: real-ear occluded responsedB SPL measured at the probe; ear canal occluded
REUG
REOG
REM • Occluded Measurements
22Inventis • Audiology Equipment
REAG: real-ear aided gain
• difference between dB SPL measured at the probe and
dB SPL measured at the reference
• it considers the amplification provided by the hearing
aid and the ear canal
• it is used to get closer to the calculated target
REAR: real-ear aided response
dB SPL measured at the probe
HA inserted and turned on (AIDED)
target
REAG
REM • Aided Measurements
23Inventis • Audiology Equipment
HA Inserted and turned on (AIDED)
REIG: real-ear insertion gain
• difference between dB SPL measured at the probeand dB SPL measured at the reference
• it considers only the amplification provided by the hearing aid, without any contributions of the ear canal
REIG = REAG - REUG
target
REIG
REM • Aided Measurements
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REM • Open fitting
users of occluded HA often complain of a lack of naturalness in the perception and amplification of their own voice
Open Fitting
• allows almost complete communication between the air outside and inside the ear canal
• for patients suffering high-frequency hearing loss (poor amplification at low frequencies)
• ATTENTION: acoustic feedback
feedback
microphone
forward path (gain)
amplificator receiver
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MPO
maximum power output
response measurement to check that theoutput (MPO) of the hearing aid does not
exceed the UCL identified for the patient, evenwhen a signal of high intensity is generated
(typically 85 dB SPL)
HA Inserted and turned on (AIDED)
REM • Maximum Power Output
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LIVE SPEECH
• live monitoring of input and output signal,aimed to focus on the real advantages of thehearing aid amplification (counseling)
• comparison between the response measuredwith the hearing aid inserted and active, withthe estimated response without hearing aid
• opportunity to use the doctor’s voice or arelative’s voice as a signal
HA Inserted and turned on (AIDED)
REM • Live Speech
27Inventis • Audiology Equipment
REM • ON TOP mode
selecting it during an AIDED, MPO or LIVESPEECH
measurement, thewindowof the program is reduced in
size,and the operator can use a hearing aid setting
application,while keeping the Maestro interface on
the screen
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TRUMPET
Inventis • Audiology Equipment
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TRUMPET
Inventis • Audiology Equipment
complete audiometer with FF speaker and REM system in a small carrying case!
size: 40 x 25 x 16 cmweight: approx. 2.5 Kg
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TRUMPET
Inventis • Audiology Equipment
Trumpet REM
system for in-situ measurements
Trumpet AUD
diagnostic audiometer
Trumpet REM +AUD
only one hardware, but 3 modules
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TRUMPET-REM
Inventis • Audiology Equipment
built-in speaker
extremely small and light probes
probe mic
hole for flexible support
reference mic
graduated scale
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TRUMPET-REM
Inventis • Audiology Equipment
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TRUMPET-AUD
Inventis • Audiology Equipment
34Inventis • Audiology Equipment
TRUMPET ON YOUTUBE
Thank youfor your attention