AP - The Recognized Standard In Audio Test



The audio analyzer designed specifically for the needs of hearing instrument manufacturers.


The APx511 Hearing Instrument Audio Analyzer is designed to meet the needs of hearing instrument manufacturers, providing the specific measurements and I/O required for hearing instrument production test, delivered with Audio Precision’s reputation for high performance and reliability.

All APx models use the same software, so with the R&D department using an APx555, APx525 or APx585 and APx511 deployed on production lines, product design is faster, interaction between Engineering and Production is easy and the AP report generated by Quality Control is trusted around the world.

IEC60118-7 / ANSI S3.22 function library

APx511 supports a .NET library of functions that automate the tests described in IEC60118- 7 and ANSI S3.22. For the production environment, these functions can be called from any .NET capable language or LabVIEW to control the APx511’s output and measurement settings.

For troubleshooting or test setup, the APx511 can be controlled by the standard APx500 software providing a rich graphical user interface and access to automated reporting, real-time signal monitors, high resolution FFTs and controls for limits & other settings.

In addition to standard audio tests such as level, distortion, frequency response, and attack & release, APx511 can measure battery current using its built-in battery simulator circuit.

Built-in support for test chamber speaker, telecoil & microphone

The APx511 generator includes an in-line 2 watt loudspeaker amplifier (8 ohms) and a telecoil amplifier, allowing >110 dB SPL and up to 400 mA/m field strength from 100 Hz to 10 kHz in a test chamber such as the Interacoustics TBS25. On the input side, APx511 supplies 24 V DC of constant current through a single BNC for a pre-polarized measurement microphone.

block diagram

All audio & power connections are located on the back of the instrument in line with production test standard practices. The microphone input is a standard BNC connector. The outputs connect via a standard DB-15 connector to reduce cabling errors in the production environment. A DB-15 break-out cable terminating in the required connectors for specific test chambers is provided with each APx511.


Key features

    • Automated routines for IEC60118-7 and ANSI S3.22
    • 2 W loudspeaker output
    • 0 – 400 mA/m telecoil field strength in Interacoustics TBS25 test chamber
    • Microphone input with 24 V DC constant current
    • 2 V DC battery simulator with current measurement
    • Share tests and results with any APx analyzer
    • Built-in test sequencer or API to VB, C#, LabVIEW, MATLAB
    • THD <-80 dB @ 2 W into 8 Ω (100 Hz - 10 kHz BW)
    • Frequency response ±0.03 dB (100 Hz - 10 kHz BW)





Download full specifications

  • Maximum output
    2 W RMS into 8 Ω (100 Hz 10 kHz BW)
  • THD+N
    -80 dB @ 2 W / 8 Ω (100 Hz 10 kHz BW)
  • Frequency Response
    ±0.1 dB (100 Hz 10 kHz)
  • Amplitude Accuracy
    ±0.03 dB (+15° C to +30° C)
  • Frequency Accuracy
    2 ppm

  • Maximum output
    100 mA RMS up to 20 Ω (100 Hz 10 kHz BW)
    (400 mA/m field strength in Interacoustics TBS25)
  • Total Harmonic Distortion
    -80 dB @ 100 mA into 1 Ω (100 Hz 10 kHz BW)
  • Frequency Response
    ±0.1 dB (100 Hz 10 kHz)
  • Frequency Accuracy
    2 ppm

  • Maximum Current
    30 mA
  • DC Output
    Range: 0 to 2V; Resolution: 0.5 mV;
    Accuracy: ± (1% + 10 mV)
  • Output Impedance
    4.3 Ω
  • Current Measurement
    Range: 0 to 30mA; Resolution: 10µA;
    Accuracy: ± 5%

  • Connector type
    BNC (includes constant current power for a standard pre-polarized measurement microphone. CCP can be also disabled for use with an external microphone power supply)
  • Power
    24 V DC constant current
  • Maximum Input
    8.5 Vrms (equivalent to 151 dBSPL at mic sensitivity of 12.5 mV/PA)
  • Residual Noise (20 kHz BW)
    < 1.3 uV (equivalent to 20 dBSPL at mic sensitivity of 12.5 mV/PA)
  • Frequency Response
    ±0.03 dB (100 Hz 20 kHz)

  • In addition to IEC60118-7 / ANSI S3.22 tests, APx511 can operate as a fully functional audio analyzer.

  • Audio measurements
    Level, Gain, Frequency response, THD+N, IMD, DC level, Noise, SNR, SINAD, Stepped frequency sweep, Stepped level sweep, Maximum output, PESQ (optional), more.
  • Real time signal monitors
    Level, THD+N, Frequency, scope, FFT
  • Max FFT length
    1248K points
  • Reporting
    PDF, MS Word, CSV, PNG
  • Measurement recorder
    Record all audio measurements continuously up to 160 hours
  • Measurement technologies
    Sine, chirp, multitone
  • Derived results
    Smoothing, min/max/statistics, normalize, invert, compare, offset
  • API
    .NET compatible plus LabVIEW driver

Specifications are subject to change.

  • PC with 2 GHz or faster multi-core processor (2 or more cores)
    Note: the Intel Atom dual-core processor does not have sufficient performance to run APx software.
  • 2 GB or more RAM (4 GB or more recommended for Windows 7 and Windows 8).
  • Microsoft Windows XP (32-bit, SP 2 or later), Windows Vista (32-bit), Windows 7 (32- or 64-bit), Windows 8 (32- or 64-bit).
  • Download System Requirements Document
  • System performance is sensitive to processor speed; faster processors will yield faster results.
  • APx500 is data intensive and it is recommended that other data-intensive applications not be run concurrently. This includes Audio Precision AP2700, APWIN or ATS.
  • We recommend and support the following specific editions of Microsoft Windows: XP Professional SP2 and SP3, Vista Business and Ultimate, Windows 7 Professional and Ultimate (32 and 64 bit), Windows 8 Pro and Enterprise (32- and 64-bit).

APx511 Statement of Use

The Audio Precision APx511 is not intended to be used as a Medical Device. It is not intended to be used for diagnostic or therapeutic purposes and is not intended to be used in or on the human body. It is not intended to be used by audiologists or for any patient specific use.

Intended Use

The APx511 is intended to be used as the signal source and signal analysis portion of a test system which measures the electrical and acoustical response of a hearing aid device while the device is enclosed in a test chamber during the production process.


The Audio Precision APx511 is intended to be used solely by hearing aid manufacturers for the purposes of (1) conducting product research and development, (2) verifying product performance during production for quality control purposes, and (3) verifying performance for hearing aids returned for evaluation or service.


Audio Precision Inc.
5750 S.W. Arctic Drive
Beaverton Oregon 97005


Phone 503 627 0832


Download APx511 Statement of Use
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