450 Harrison Ave • Suite 307 • Boston • MA 02118 • Tel: (617) 556-4104 • Fax: (617) 556-4104 • email: info@listeninc.comwww.listeninc.com

Hearing Aid Testing

• Standards: ANSI S3.22-1996, IEC118-7, JIS, Chinese National Stan-dard GB 7263-87

• OSPL• Max OSPL• HFA-OSPL• Full-on gain• HFA FOG• Reference-test gain• Frequency-response range• THD• Equivalent Input Noise Level• Battery Current Drain• SPLITS• HFA SPLITS• Input vs. output level• Attack & Release TimeA

PP

LIC

AT

IO

N N

OT

E

System Overview

Industry Standard Tests

SoundCheckTM is an easily configurable, windows-based system for efficient and comprehensivetesting of hearing aids.

Applications include:• Incoming Inspection• Pre and Post service evaluation• Research and Development• Amplifier test and measurement• Evaluating audio performance of DSP

algorithms

Utilizing a variety of readily available hardwareand software, including anechoic test chambers,ear couplers, microphones, and databases,SoundCheck can measure and report allparameters related to hearing aid test andmeasurement to in-house, ANSI, IEC, JIS, andother standards. In addition, SoundCheck cancontrol external devices, such as Hi-Pro or aturntable, using RS-232, USB, or IEEE interfaces.

SoundCheck is fast for production linemeasurements, performing comprehensive tests,such as ANSI S3.22 1996, in less than 20seconds. Test sequences can be pre-programmedfor simple pass/fail analysis or detailed results thatcan be exported to other programs for additionalprocessing and generating documents instandardized formats. SoundCheck can be easilyintegrated into existing test programs that utilizeActiveX controls or National InstrumentsLabVIEW®. One-button operation, barcode controland assignable security levels give you totalcontrol over your production testing.

SoundCheck also offers unrivalled flexibility forR&D applications - with SoundCheck, you are nolonger constrained by the limitations of proprietaryhardware-based systems for testing hearing aidsand associated subcomponents. SoundCheck iseasily configurable, making it perfect for a labora-tory environment where a large number of differenttests need to be carried out. Tests can be selectedfrom a standard library and customized testsequences can be programmed and modified via asimple point-and-click programming interface. Any.wav file can be used as the input stimuli, includingsine, noise and real speech. One-button calibra-tion, a large number of measured data points and

advanced mathematical algorithms ensure unpar-alleled accuracy for measurements in both the timeand the frequency domain.

Features and Benefits

www.listeninc.com

Hearing Aid TestingTypical System Configuration

A typical hearing aid test system consists of the SoundCheck Basic Software with optional SoundWare Hear-ing Aid Module, computer, sound card, audio amplifier, microphone, microphone power supply, coupler andanechoic test box (options may vary depending upon application).

Left Amp Output to Speaker Input

Hearing Aidin coupler

SoundCard Input

Sound Card Output

to Amp Input

Power Amplifier

PASSED

SoundConnectMic Power

Supply

Anechoic Test Chamber

Right Amp Output to Telecoil Loop Input

SoundCheck™for Hearing Aid

Testing

DC Connect

USBconnection

to PC

DC Voltageto BatteryAdapter

Input

ANSI Test Report.

One-button CalibrationThe entire measurement chain includingtransducers, audio amplifiers, and sound sources iscalibrated by simply clicking on one button inSoundCheck. An external acoustic calibrator isused to calibrate the measurement microphone,which then can be used to calibrate the anechoictest chamber. The magnitude and phase of the testchamber’s sound source is equalized for a flatresponse. Typical sound pressure variation at thehearing aid’s microphone position is within ± 0.2dBfrom 100Hz to 10kHz.

Application-specific ModulesSoundCheck application-specific modules enableyou to create functionality specific to yourmeasurement needs and budget. SoundWaremodules include the Signal Generator, Voltmeter,Oscilloscope, Spectrum (FFT), and Real TimeAnalyzer. For real-time “hands-on” investigation ofhearing aid performance, the Signal Generator canplay a sine wave, a speech signal or any WindowsWAV file at a calibrated output level. The details ofthe hearing aid can then be analyzed in thefrequency and/or time domain using theOscilloscope, FFT or Real Time AnalyzerSoundWare modules.

LimitsLimits can easily be created from a measuredresponse by offsetting the curve in frequency,amplitude, or time. When testing to a specificstandard, such as ANSI S3.22-1996, the limitcurves can float in either amplitude or frequency.

Post-processingOptional post-processing modules allow measure-ment of Attack and Release time, curve statistics(e.g. HFA or SPA), as well as curve arithmeticoperations (e.g. difference curves) as required fordetermining Reference-test gain.