100 Things #67: Measuring Active and Passive Noise Cancellation for Hearing Protection

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SoundCheck makes testing to standards simple by automating precise measurements into a single sequence. In this test sequence hearing protection devices can be tested to the ANSI S3.19-1974 standard to find their NRR rating. Sequences in SoundCheck make testing simple, with message steps instructing operators when interaction is needed with removing or placing hearing protection DUTs, for example. ListenInc.com features an extensive list of pre-written test sequences for any application including noise protection devices, hearing aids, bluetooth devices, and more.

Measuring Active and Passive Noise Cancellation for Hearing Protection

Try our hearing protection sequence for yourself

The hearing protection measurement sequence featured in this video is available in our sequence library.

Video Script:

Did you know that you can test hearing protection devices to industry standards using SoundCheck? Let’s take a look. 

Hearing protection devices are often measured to the ANSI S3.19-1974 standard which measures the Noise Reduction Rating or NRR of the device. This rating is a numerical representation of the device’s sound attenuation.

Our test sequence first measures the response spectrum of the unoccluded hearing protector test fixture, then makes a second measurement with the hearing protection DUT affixed. SoundCheck’s signal generator generates the pink noise stimulus while its Real Time Analyzer simultaneously records the A and C weighted noise spectrums. The unoccluded and occluded measurements are analyzed with a series of post-processing steps according to the ANSI S3.19-1974 standard. The final display shows the NRR numerical value, RTA spectra of the left and right side of the unoccluded and occluded hearing test fixture, average attenuation level of the DUT, and the standard deviation of the DUT on the test fixture.  The sequence prompts the user to recall previously saved unoccluded measurements and standard deviation values, saving time if the test fixture and DUT have been measured previously. When a new unoccluded measurement is taken, the user can save these measurements for a future data recall. 

We have many SoundCheck test sequences written by experts to  save hours of time writing them yourself. Most of these, including this NRR sequence, are free to use and come with well written step-by-step instructions.