Introduction to the FONIX 7000 Hearing Aid Test System

1
Introduction to the FONIX 7000 Hearing Aid Test
System

• Software version 1.60

2
Outline

• Coupler Measurements
• Basic (ANSI, Coupler Multicurve)
• Testing Digital Aids
• Open Fit Coupler
• Measuring directionality
• Automation
• Advanced Coupler
• Real-Ear Measurements
• Entering an audiogram
• Insertion Gain
• Testing directionality
• Real-ear SPL
• Visible Speech
• Testing Open Fit hearing aids
• Default Settings

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Basic Coupler Measurements
ANSI 03 F4
Coupler Multicurve F1
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ANSI 03 Settings
Aid type
Telecoil
Frequencies
Choose ear
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ANSI 03 Results
Max
OSPL90-HFA
OSPL90
Distortion
FOG
EIN
Response curve
Telecoil
Battery current
Attack Release
I/O curves
Telecoil
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Coupler Multicurve Features

• Realistic frequency response measurements
• Variety of signal types Composite, Digital
  Speech, Pure-tone sweeps
• Display 10 different curves simultaneously
• Switch back and forth between gain and output.
  All curves translated.

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Coupler Screen Operation
Amplitude
Choose Ear
Select Curve
Source Type
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Example
50 dB
60 dB
70 dB
80 dB
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Testing Digital Aids

• Digital Speech
• Type of Composite signal
• Modulated to allow testing of noise reducing
  digital aids
• Used with ANSI or ICRA speech spectra

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Example of digital aid test
Digital Speech
Composite
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Testing Open Fit Hearing Aids

• The Open Fit Coupler was designed to
• Provide a realistic response for open fit hearing
  aids.
• Provide an easy mechanism for attaching an open
  fit hearing aid to a coupler
• The Open Fit Coupler is a non-standard sized
  coupler not designed to test to manufacturing
  specifications

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Attaching the Open Fit Coupler
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Testing Directionality

• Use chamber design to perform forward and
  reverse measurements to obtain directional
  advantage
• Chamber speaker mounted at 45 degree angle,
  pointing towards left side of chamber

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Forward/Reverse Positioning
Forward positioning with hearing aid pointed
towards sound chamber speaker
Reverse positioning with hearing aid pointed
away from sound chamber speaker
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Directional Advantage
Forward measurement
Reverse measurement
6 dB RMS Difference
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Coupler Automation

• Set up own test sequence
• Select signal type for each curve
• Select signal amplitude for each curve
• Add any desired pauses in test sequence
• Save and auto load test sequence

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Programming Auto Mode
Help window w/instructions
F6 Program Mode
F5 Source Type
Amplitude
START
Advance to next curve without pause
Advance to next curve with pause
STOP
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Example of Auto Test
Digital Speech _at_ 50, 65, 80 dB
Pure-tone sweep _at_ 90 dB
F6 Fully Automatic mode
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Saving and Loading Settings
Automatically load saved curve group and put
analyzer in Auto Mode
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Advanced Coupler

• Battery Current F1
• Coupler I/O F2
• Attack Release F3
• Enhanced DSP F4
• Function key operations available in the Advanced
  Coupler Navigation Screen

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Battery Current Screen

• Measure Battery Current as a function of
  frequency
• Measure Battery Current as a function of
  amplitude
• Estimate battery life of hearing aid

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Battery Current Test
Battery current by amp
Battery current by freq
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Coupler I/O

• Composite or Pure-tone source types
• Any Freq from 200 to 8000 Hz in 100 Hz intervals
• Display results in Output (SPL) or Gain
• Graph and data results given

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Coupler I/O Test Results
Test Results
Frequency
F5 Source Type
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Attack Release Test Screen

• Visual time graph of Attack and Release tests
• Scale graphs independently to zoom in on results
• Use Composite or Pure-tone
• Choose any frequency from 200-8000 Hz in 100 Hz
  intervals
• Customize amplitudes used in tests

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Attack Release Results
Frequency
F5 Source type
F6 F7 Change graph scales
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Enhanced DSP

• Designed to measure the "group delay" of a DSP
  aid. In other words, the actual digital
  processing time of a hearing aid.
• 0 ms for analog aids
• 1-12 ms for DSP
• Great way to check if aid is analog or DSP
• Also tests the "phase" of a hearing aid. This is
  useful for binaural fittings. Are the aids
  working together?

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Technical Details Group Delay
An impulse signal is delivered to the hearing
aid. The time of the maximum peak of the
response is considered the group delay. The 7000
system delay is subtracted from this value to
obtain the final measurement.
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Technical Details Phase
One pulse of a 1000 Hz cosine signal is delivered
to the aid. This signal is 1 msec long. The
first 20 msec of the aid's response to the signal
is displayed in graphical format.
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Example
Group Delay
Phase
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Basic Real-Ear measurements
Use the function keys to enter a screen
F1 Audiogram Entry
F2 Target Edit
F3 Insertion Gain
F4 Real-ear SPL
F5 Visible Speech
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Entering an audiogram
Adjust amplitude
Adjust frequency
Real-Ear SPL only
F1 Select ear
F3 Predict UCLs
F2 Select HTL/UCL/Bone
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Insertion Gain features

• Unaided measurement
• Up to 4 aided measurements
• Gives up to 4 insertion gain measurements
• Operation similar to coupler screen

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Insertion Gain screen
Target
Insertion Gain
Aided
Select amplitude
Unaided
F1 Select ear
F2 Select curve
F5 Select source type
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Step 1 Setup
Reference Mic
Speaker should be 12 inches from patient at 45
degree angle
Probe Mic
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Step 2 Level
LEVEL
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Step 3 Unaided Measurement
START
STOP
Peak at 3 kHz
Amplitude
Negative response at 6 kHz shows probe tube could
probably be inserted more deeply
F2 - REUR 1
F5 - DigSpeech
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Step 4 Aided/IG measurements
IG Target
IG curve
F2 REAR 2
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Multiple Aided/IG measures
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Testing Directionality
Directional Advantage
CRV 2 Forward response
CRV 1 Reverse response
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Real-Ear SPL screen

• Check low inputs are above thresholds
• Check average inputs meet target
• Check loud inputs are below UCLs
• Auto-adjusting REUR shows amplification benefit
  at all levels
• Gives overall look at hearing aid fitting
• Operation similar to coupler IG screens

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SPL operation
U UCLs
H, M, L Targets
T Thresholds
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Auto-Adjusting REUR Option
REUR 1 automatically adjusts when the 80 dB REAR
4 curve is selected
REAR 4 _at_ 80 dB
REUR 1 adjusted to 80 dB
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Visible Speech

• Use live speech signal
• Real-time response (during test)
• Average response
• Minimum and maximum response per frequency for
  the length of the test
• HTLs
• UCLs
• All on one graph in dB SPL

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Visible Speech Before Test
UCLs
Targets
HTLs
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Visible Speech Test Results
UCLs (off screen)
Max boundary
Avg Response
HTLs
Min boundary
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Open Fit Hearing Aids

• Some Open Fit hearing aids interfere with the
  reference microphone measurements outside the
  ear.
• Disable the Reference Microphone in the local
  menu to perform real-ear on these hearing aids.
• Real-ear targets may prescribe low frequency
  amplification unsuitable for open fit hearing
  aids.

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Default Settings

• Press MENU from the Opening Screen to enter the
  Setup Menu
• Use F1 in the Setup Menu to choose between
• General Settings
• Coupler Settings
• Real-ear Settings