Introduction to the 8000 Hearing Aid

Test System

By: Kristina FryeFrye Electronics, Inc.

Outline Coupler Measurements

Coupler Directional ANSI/IEC Coupler Multicurve Advanced Coupler: Enhanced DSP, Attack &

Release, I/O, Battery Current

Coupler Directional

F3 – Advanced Coupler F5 – Coupler Directional

Directional Measurements

Polar Plot

Difference (0° vs 135°)

Simultaneous, Manual, and Auto Modes In Simultaneous Mode, five polar plot curves are

measured simultaneously A Composite source signal is used to take the

measurements. The response at specified frequencies is graphed

In Manual Mode, the user selects the curve to measure. A Puretone signal at the user specified frequency or a Composite source is used.

In Auto Mode, the user can pre-save manual measurements and run curves automatically

WinCHAP Data Grab

Basic Coupler Measurements

ANSI 03 — F4Coupler Multicurve — F1

ANSI 03 Settings

Choose ear

Aid type

Frequencies Telecoil

ANSI 03 ResultsOSPL90

Response curve

Max

OSPL90-HFA

Distortion

FOG

TelecoilEIN

Battery current

Telecoil I/O curves

Attack & Release

Troubleshooter ANSI

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.

Coupler Screen Operation

Choose Ear

Select Curve Source Type

Amplitude

Example

50 dB

60 dB

70 dB

80 dB

Troubleshooter Coupler Multicurve

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

Example of digital aid test

Digital Speech

Composite

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

Attaching the Open Fit Coupler

CRV 1 = Open Fit CouplerCRV 2 = HA-1CRV 3 = HA-2 w/attachmentCRV 4 = KEMAR

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

Programming Auto Mode

F6 — Program Mode

Help window w/instruction

s

F5 — Source TypeAmplitude

START

STOP

Advance to next curve without pause

Advance to next curve with pause

Example of Auto Test

Digital Speech @ 50, 65, 80 dB

Pure-tone sweep @ 90 dB

F6 — Fully Automatic mode

Saving and Loading Settings

Automatically load saved curve group and put analyzer in Auto Mode

Troubleshooter ProfilerGreat for baseline testing… save time!

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

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

Coupler I/O Test Results

Frequency

Test Results

F5: Source Type

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

Attack & Release Results

Frequency

F5: Source type

F6 & F7: Change graph scales

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?

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.

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.

ExampleGroup Delay Phase