Real Ear Attenuation at Threshold (REAT) Systems for Hearing Protector Testing

VIacoustics Real Ear Attenuation at Threshold (REAT) audiometric measurement systems test in accordance with standard test methods* on earplugs, earmuffs and other hearing protection devices and systems. The REATPro software, when used in conjunction with our Trident software, also supports many other measurements commonly conducted in hearing protector test laboratories, including MIRE and fixture based testing of hearing protectors. REATPro is an automatic Bekesey audiometer program designed to provide stimulus and track responses for sound field hearing threshold determination for both occluded and unoccluded conditions. REATPro also provides calibrated signal generation for all tests including MIRE and fixture based tests.


  • Tracks both unoccluded and occluded hearing thresholds
  • Provides both thresholds and trace history
  • Provides tools for sound field calibration
  • Automated attenuator control and gain adjustment
  • Data export into MSExcel for post-process analysis and reporting

Contact us about building a Real Ear Attenuation at Threshold system featuring our REATPro Software for your audiometric testing lab. Browse through the components that make up these systems, features of the REATPro software, and services provided on the following tabs.

*Standardized test methods:

Code of Federal Regulations (CFR) 40, Part 211, Subpart B – Hearing Protective Devices

ISO 4869-1:2018 Acoustics — Hearing protectors — Part 1: Subjective method for the measurement of sound attenuation

ISO 4869-3:2007 Acoustics — Hearing protectors — Part 3: Measurement of insertion loss of ear-muff type protectors using an acoustic test fixture

ISO/TS 4869-5:2006 Acoustics — Hearing protectors — Part 5: Method for estimation of noise reduction using fitting by inexperienced test subjects

ANSI S12.6 – Methods for Measuring the Real-Ear Attenuation of Hearing Protector

ANSI S3.19 – Method for Measurement of Real-Ear Protection of Hearing Protectors and Physical Attenuation Ear Muffs

Australian/New Zealand Standard 1270:2002, Acoustics – Hearing Protectors

Components of the Real Ear Attenuation at Threshold (REAT) Systems for Hearing Protector Testing:
Trident logo

Nelson Acoustics Trident software is a real time multichannel, multiple analysis acoustic measurement application for use in acoustic and hearing sciences laboratory applications.

REATPro Real Ear Attenuation at Threshold Software

Real Ear Attenuation at Threshold (REAT) Testing Application for Hearing Protection Evaluation

NI PXI Chassis

Our preferred form factor for laboratory measurement systems and high channel count systems.

NI PXIe-4463

2 analog output channels 24 bit, 204.8 kHz sampling; 118 dB dynamic range 3 analog gain settings NIST Traceable Calibration Installs in PXI expansion chassis such as PXIe-1073 or PXIe-1082 for high channel count applications   National Instruments PXIe-4463

NI PXIe-4464

The National Instruments PXIe-4464 is our standard data acquisition card for laboratory sound pressure level measurement and sound power level determination of low noise products. It is also used for high speed time waveform recording for our impulsive measurement applications.

NI PXI-6220

A low cost solution for digital I/O and reading analog sensors.

G.R.A.S. 46AQ

1/2″ Random Incidence Microphone for use in Reverberant Test Environments

G.R.A.S. Low Noise Microphone Systems

State of the art transducers for laboratory measurement of products with very low noise emissions.

intelligent pistophone
G.R.A.S. Microphone Calibrators

G.R.A.S. calibrators provide a traceable daily calibration reference for your acoustic measurement system.

Desktop PC

VIacoustics provides fully integrated acoustic measurement systems with a personal computer as a host, and insure compatibility with all hardware and software.

Shure 522 Base-Station Microphone

This desktop microphone is used in the REAT system to talk to test subjects from the control room. It has a push-to-talk button, which is integrated into the system to control muting of the boundary microphone in the testing room and eliminate feedback.

Furman Elite-15 PFI

The Furman Elite Power Conditioner is used in REAT systems to ensure stable power and reduce electrical noise to all components of the system.

Crown 135MA Three Input, 35 Watt Mixer-Amplifier

These amplifiers are used in our REAT systems for talk-back and talk-forward microphones, and support muting via external switch. This is useful to avoid feedback when communicating back and forth between testing and control rooms.

Bryston 6BSST² Three-Channel Amplifier

Paired with our custom built high-power attenuator, this amplifier supplies the power to generate a sound field with a noise floor below the threshold of human hearing, which is necessary for Real Ear Attenuation at Threshold (REAT) test systems.

response switch attenuator control front
VIacoustics Response Switch and Attenuator Control Unit

Interfaces with optical and mechanical switches, controls L-pad via software, and controls muting of intercom in REAT systems.

lpad front
VIacoustics High-Power Attenuator (L-pad)

Our custom built High-Power Attenuators provide up to 30dB of attenuation. Combined with the high power a Bryston 6BSST² Three-Channel Amplifier we can reduce the noise floor of the sound field to below the threshold of hearing, which is essential for REAT testing.

gst590_microphone accessory
Microphone Accessories

VIacoustics turnkey measurement systems can include microphone stands, fixtures and cables needed to facilitate your acoustic measurement.

Real Ear Attenuation at Threshold (REAT) Systems for Hearing Protector Testing Features at a Glance:
3d database with tools
REATPro – Setup

REATPro provides flexible configuration options to support a variety of data acquisition systems and audiometric testing protocols. 

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REATPro – Manual / Calibration

The Manual / Calibration tab can be used to present and calibrate any stimulus at any level to any or all outputs, continuously or pulsed. This can be useful for subject training, checking that the sound system is functioning and troubleshooting problems.

Illustration of the nurse files on a white background
REATPro – Documentation

Retrieve prior thresholds from subject for comparison with current thresholds as required by ANSI S12.6. Define test type: qualifying subject, training as subject, conducting protector test. Subjects are tracked by subject ID for HIPA compliance. Document what protector is being tested. Load expected attenuation to speed up occluded threshold seeking.

REATPro – Test Execution

Runs in automated manor from first to last frequency. Runs both unoccluded and occluded modes. Unoccluded mode has max level protections to ensure subject safety. Provides level tracking and current threshold info with comparison to prior threshold.

Business data financial report print close up. Blue toned.
REATPro – Excel Export

Export to MSExcel based template files that users can customize to meet their own needs. Both Unoccluded and Occluded thresholds, as well as the sound pressure level vs time trace history to MSExcel for detailed analysis of threshold determination time and reversal history. A file header section provides documentation on all test setup parameters.

A concept vector illustration showing an apple and an orange on scales. Attempting to compare apples and oranges.
REATPro – Comparison

Allows comparison of subject threshold to qualifying average. Comparison of unoccluded thresholds within a session. Indicates compliance with ANSI S12.6 requirements.

Real Ear Attenuation at Threshold (REAT) Systems for Hearing Protector Testing Related Services:
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System Integration

VIacoustics turnkey measurement systems are built in a working acoustics laboratory and are fully assembled, calibrated and tested for plug and play operation when the arrive at your site.

Technical support. On line service. Isolated 3D image
Onsite Installation and Training

VIacoustics turnkey measurement systems are shipped to your site ready for final installation and plug-and-play operation.

Customer support
System Support Services

VIacoustics turnkey measurement systems include post installation support via telephone, e-mail and/or online support sessions.

Please contact VIacoustics at for information on pricing.