100 Things you didn’t know about SoundCheck videos

100 Things #85: Integrate Soundcheck Data With Your Database

Using SoundCheck as part of your test setup and database is easy. SoundCheck’s data can be saved directly to Microsoft Access or an SQL database, all from within a sequence. This includes curves, values, results, and waveforms. SoundCheck’s autosave sequence steps can automatically gather, format, and export sequence data. Plus, with TCP/IP integration, SoundCheck’s data can be accessed and ready to use in your own program.

Integrate Soundcheck Data With Your Database

Learn more about SoundCheck integration

SoundCheck includes examples scripts for externally controlling SoundCheck via TCP/IP. C sharp, C++, LabVIEW, MATLAB, and Python examples are included.

Our SoundCheck tutorial series covers everything you need to know to get testing with SoundCheck, including how to configure SoundCheck autosave steps with a database. Check out the Autosave to Database tutorial, or the full tutorial playlist.

The SoundCheck manual gives detailed written instructions on setting up your database with SoundCheck, configuring TCP/IP connections, and more.

Video Script:

SoundCheck performs many measurements on your audio device – frequency response, sensitivity, harmonic distortion, perceptual distortion, transient distortion, directivity, pass/fail results and more. When you test hundreds, or even thousands of devices a day on a production line, that’s a lot of data. Everyone wants to manage this differently, so we offer several different database options for seamless integration with your manufacturing and business intelligence systems.

Directly in a SoundCheck step, you can save your curves, values, results, or waveforms to a database. Using an autosave step you can make a connection to a Microsoft Access or SQL database so that whenever your sequence runs,  the data is sent to the database. Industry standard tools can then be harnessed to run analytics over large data sets. For example, a procedure could be created to examine the frequency response on all measured devices on the database and create limits based on the average. 

Even if you’re not using a database, SoundCheck still has options to get your data into a format that’s easy to work with. In addition to the options shown directly in the autosave editor  – that’s text, csv, Excel, TDMS, Matlab .dat, .wfm, and.res, there’s also a plugin available to transfer data to WATS. WATS is a full test data management platform created by Virinco that can quickly and easily take production data and place it into dashboards to help see your production statistics at a glance. 

If these options aren’t enough, all the data, curves, and other  items saved in SoundCheck’s memory list, can always be accessed directly via TCP/IP. This means you can write your own customized program to collect exactly the SoundCheck data you need. Simply read the memory list items using a TCP/IP connection to the SoundCheck computer and you’ll have all the measurements ready to go in your own program. We have some very basic examples of this included with the Soundcheck installation in the external control examples folder, but the final product can be as specific to your use case as you need. 

Hopefully this brief introduction has demonstrated how SoundCheck’s flexible data management enables it to be easily integrated into your test environment. Check out the SoundCheck manual for detailed information on how to set up database connections, use TCP/IP and more.

100 Things #83: Open Loop Measurements Of Smart Devices

Open loop testing enables measurement of smart devices, phones, and any device that cannot play a stimulus and record at exactly the same time. Both speakers and embedded microphones on these devices can be measured with SoundCheck, thanks to it’s module test architecture. With SoundCheck, the stimulus and acquisition are separated, so a stimulus file can easily be loaded onto a smart device and triggered either manually or via network commands. For internet connect devices like smart homes, stimulus files can be uploaded and played directly from the cloud.

Open Loop Measurements Of Smart Devices

Learn more about testing smart devices

Our full Smart Device Testing seminar features test demonstrations of smart homes, Bluetooth headphones, and active noise cancellation. Device design considerations and individual component tests are shown, and how SoundCheck can measure audio quality from R&D to production.

Video Script:

Open loop testing lets us measure a device when it’s not possible to play the stimulus and record the response from SoundCheck at exactly the same time, for example smart devices, phones and more. This is simple in SoundCheck, since its architecture has always allowed analysis to be performed independently of acquisition. In fact, we pioneered open loop testing, originally for testing MP3 players,  back in 2006 – a good 10 to 15 years before others started implementing this capability.

Let’s start by explaining how open loop testing is different from conventional closed loop tests. In conventional audio tests, such as speaker and microphone tests, the stimulus playback and response recording occur simultaneously. The two signals are correlated, and ready to analyze.

Devices such as mobile phones and smart speakers do not have a simultaneous input/output audio path, but we can test both the speakers and the microphone using open loop testing. In open loop testing, the stimulus includes a trigger to tell SoundCheck when to start recording. 

Let’s look at a mobile phone test. For the speaker, a stimulus file is loaded onto the phone and played back either manually or via a command. SoundCheck records the response using a trigger record acquisition. To test the microphone, a stimulus is played through a mouth simulator, and manually or via a command recorded to the phone. The recording is then transferred to SoundCheck for analysis. 

I’ve already uploaded the stimulus file onto my phone, and I’ll manually playback the stimulus file and trigger the record in SoundCheck.  This short “sine chirp” in the stimulus file serves as the trigger and is not analyzed. This is  a sophisticated level and cross-correlation trigger that is more robust and less susceptible to false triggers than simple level and frequency options. The test sequence then uses resampling and  frequency shift post processing steps in the sequence to correct for sample rate mismatches and slight sample clock differences between the device under test and your test interface. This enables perfect alignment of stimulus and response for accurate analysis. I’ll run the sequence…

There you go. The top graph displays the frequency response of the phone’s speaker, to the right is the recorded response superimposed over the stimulus, the bottom graphs include THD, Rub and Buzz and Enhanced Rub and Buzz.

Let’s look at some other examples. These Apple “lightning” wired  earbuds can’t be tested using a standard headphone test interface as these do not support the proprietary connector. However,  the lightning earbuds can be connected to an iPhone, and the phone can playback the test stimulus.

Open loop testing even allows testing via the cloud. With a smart speaker, the stimulus file can be uploaded to the cloud, and accessed and played back from the cloud via voice command through the speaker, using the same triggered record acquisition that I demonstrated earlier.

These are just a few common examples, but with these methods, you can measure just about any device or system that does not have a direct wired connection between signal input and output. Check out our seminar on smart device testing for more open loop demos.

100 Things #82: Measuring Audio Leakage From A VR Headset

Virtual Reality Headsets may be new to the market, but users already expect excellent sound quality to enhance the immersive experience. SoundCheck’s flexibility means you can measure almost any device including VR headsets, by leveraging it’s step-based sequence functionality. VR headset measurements can be made with the same parameters as any other headset; frequency response, perceptual distortion, phase, and more. With the addition of the MDT-4000 turntable, headset audio leakage can be measured to better quantify what people nearby would hear from a user’s VR headset.

Measuring Audio Leakage From A VR Headset

Try VR headset measurements for yourself

Our pre-written VR Headset Leakage Measurement sequence takes the guesswork out of VR headset measurements, with commands pre-programmed to work with the PT&D MDT-4000 turntable.

Video Script:

Virtual Reality and Augmented reality headset measurements are made in pretty much the same way as other headphone and headset measurements. However, one thing to be aware of is that VR and AR headsets often have the speakers located in the headband. This means that you need to use a head and torso simulator where the speaker can be in a realistic position relative to the ear, rather than lower cost couplers or headphone test jigs that rely on the headphone sitting directly in, or on the fixture to create a tight seal. 

With this setup, you can use any of our standard headphone test sequences to measure frequency response, phase, distortion, impedance, sensitivity and other parameters.

Another measurement that is particularly useful for virtual reality headset characterization is headset leakage. With the speakers unoccluded on the headband – not sealed on the ear canal –  there can be considerable acoustic leakage, and designers try to minimize the noise emanating from the device so as not to annoy other listeners nearby. 

Here, we’ll use a measurement microphone to simulate what the nearby listener hears from the person wearing the VR headset and a turntable to produce a polar plot showing the level of leakage from the VR headset versus angle. You can set the microphone position to whatever distance you want to measure, and define the test level. When we run the sequence, it plays a test signal and the microphone records the acoustic leakage. The turntable then rotates through 10 degrees and re-measures. We repeat this through 180 degrees, and mirror the results to get a full 360 degrees plot. This test sequence also shows the frequency response at each angle. This sequence is available free of charge on our website if you want to try it out.

100 Things #81: Using Statistics to Overcome Fit Variation for Headset Measurements

SoundCheck’s statistics allows for multiple measurements from a sequence to be analyzed together, to determine results like average and standard deviation. Using statistics can overcome placement variations when measuring headsets on a head and torso simulator. This sequence demonstrates a measurement of a USB headset, performed five times, where the headset is removed and repositioned on the HATS each time. SoundCheck’s statistics then take these five measurements, account for the differences in placement, and display an accurate set of measurement results. If you are testing to standards then statistics makes measurement of communications devices fast and repeatable.

Using Statistics to Overcome Fit Variation for Headset Measurements

Try measurement statistics in SoundCheck

Learn more about our pre-written TIA-920-B test sequence mentioned in this video. This pre-written sequence tests to TIA 920-B, a comprehensive US dual-bandwidth standard that applies to both narrowband (NB) and wideband (WB) devices.

Video Script:

Statistics have been a feature in SoundCheck for a very long time. But did you know that statistics can be used to overcome fit variation when measuring body-worn devices? Let’s look at how we can use this feature to make repeatable TIA-920B measurements on headsets?

For realistic and accurate results, headsets and other body-worn devices should be measured on a Head And Torso Simulator, or HATS, placed just as worn by real users. Unfortunately, small changes in position can lead to significant changes in both the level and the sound quality, whether on a real person or HATS.

For example, when placed carefully, the receiver of our USB headset sounds like this. (Audio example 1: proper placement)

When placed poorly, it sounds like this. (Audio example 2: improper placement)

To obtain repeatable results, we make several measurements and average the results, using the Statistics Step.

The headset is completely removed from HATS after each measurement, then repositioned for the next. With practice, 5 measurements are usually enough. This procedure is defined in ITU-T P.380 and IEEE 269 and used in Listen’s pre-written sequences that implement TIA 920-B.

Let’s make some measurements.

We are testing a USB headset that has two receivers and a boom microphone, intended for speech communication. There may be some speech-sensitive signal processing, so the test uses real speech. The signal is played out to the receivers first, then to the HATS mouth.

When the first measurement is finished, the receive frequency responses and single parameters such as output level are shown on the top line

In a similar way, the sidetone frequency responses are on the second line, and the send frequency response is on the bottom line.

After 5 measurements, with re-positioning between each measurement, we can see the individual frequency responses. Let’s take a closer look at the Left receive frequency response. The individual frequency responses are in gray, the current measurement in white, and the current mean in blue.

After the last of the measurements, we can see the mean results. Tolerances from the standard have been applied to the mean receive and mean send frequency responses.

The standard deviations show the repeatability of the individual measurements. If the standard deviations are within the tolerances, the mean results are acceptable. When results from 2 or more operators using this method are compared, the mean results will usually be very close, even if the individual measurements are somewhat different.

Statistics helps overcome fit variation to make accurate and repeatable measurements of headsets, as well as most other body-worn devices such as helmets, goggles, parrots and so on. And, if you are making TIA-920-B measurements on such devices, you can save a lot of test writing time with our pre-written TIA-920-B sequences. These can be used for USB, Bluetooth or wired analog devices, and there are also open-loop sequences for testing devices that connect to a server.

100 Things #80: View Data in Real Time With the Multi-FFT and Multi-RTA

SoundCheck’s powerful virtual instruments let you perform measurements in real time, now with even more multichannel features in SoundCheck 21. Our new Multi-FFT allows for multiple FFT spectra on a single instrument, displayed in real time. The Multi-RTA virtual instrument enables multiple channels of measurement, also in real time. Both instruments can have independent per-channel configuration, perform real time calculations like power averaging, all can all be displayed on a single instrument. Of course, these instruments can be included within a sequence, so you can take advantage of the power measurements with SoundCheck sequence automation.

View Data in Real Time With the Multi-FFT and Multi-RTA

Learn more about the Multi-FFT, Multi-RTA, and more

SoundCheck features a full array of powerful virtual instruments, including the new Multi-FFT and Multi-RTA. Check out SoundCheck’s full features and functionality to learn more.

Video Script:

Did you know that SoundCheck is the first Audio measurement system to offer multi-channel Real Time N-th Octave and FFT Spectrum analyzers that not only displays multiple signals simultaneously, but can also perform basic mathematical operations such as curve subtraction and power averaging in real time?

Both the Multi-RTA and Multi FFT instruments  support any number of channels, limited only by the physical test interface you are using with SoundCheck, and each channel can be configured independently. 

The Multi RTA allows you to analyze a signal using Constant-Percentage Bandwidth filters from Octave to 1/24th of an octave resolution. This is typically used for analyzing non-stationary signals such as speech and music on audio devices (such as smart devices). It can also be used for measuring active noise reduction with pink noise.

The Multi FFT uses  high resolution constant bandwidth filters that enables any number of live FFT spectra to be simultaneously viewed in real time. This resolution is helpful for viewing narrow frequency components such as pure tones and harmonics.

Both instruments offer real time calculations such as channel subtraction, maximum, minimum, average  and power calculations. These are displayed in the instrument in real time. This is useful, for example, for spatial averaging the sound pressure level  of a 6 mic array in automotive cabin measurements, or quickly checking headphone or earbud fit and seal before performing a measurement.

Another thing that’s really slick about this is that the FFT and RTA can be viewed simultaneously, either side by side or superimposed on one another in a single multi instrument. This enables both high resolution spectra and constant percentage bandwidth resolution (e.g. 1/12th Octave) measurements to be viewed at the same time. 

This could be used for analyzing broadband speech signals while accurately identifying single frequency interference tones, or analyzing intermodulation distortion in the presence of speech or music.

Another thing that you can do is drag and drop curves from the multi-channel instruments into another graph, or drag a static curve from another graph into the FFT or RTA to use as a reference. This has many applications such as comparison to a headphone target curve or automotive tuning applications.

We first introduced the Multichannel RTA in SoundCheck 19, added some extra functionality in SoundCheck 20, and introduced the multichannel FFT in SoundCheck 21. So if you’re using an older version of SoundCheck and want to check out this new functionality, contact your sales engineer or local rep to discuss an upgrade.

100 Things #79: Lock and Password Protect Your Test Sequences with Sequence Protection

With sequence protection in SoundCheck, sequences can be password protected, preventing unauthorized modification and viewing of sequence steps and data. This feature is perfect for distributing developed sequences to third parties, where you can rest assured that sequence parameters like limits cannot be changed to alter results. Sequences can even be locked to a specific set of SoundCheck hardware keys, so only authorized systems can access the sequence. All protected SoundCheck sequences are encrypted for maximum security.

Lock and Password Protect Your Test Sequences

Check out even more SoundCheck features and functionality like sequence protection

SoundCheck is built from the ground up to be the most flexible, reliable test system. Read on about all of SoundCheck’s capabilities like sequence protection and more.

Video Script:

It’s always been easy to share SoundCheck test sequences with your colleagues and manufacturing partners, but did you know that sequences can be locked to prevent modification, and conceal your test details? This stops your colleagues from altering them without your knowledge, and also prevents them from being copied and misappropriated if they are shared outside your organization.

Locking a sequence and password protecting it is simple. You can run the sequence as normal, but once it’s in the locked state, it cannot be modified without the password – steps, limits and other sequence parameters cannot be changed. Furthermore, the sequence details cannot even be viewed, protecting the intellectual property in your sequence.

This means that if you’re sharing your test sequences with 3rd parties –  for example, contract manufacturers – you can be confident that your products are tested exactly how you intended. No-one can adjust the limits to achieve higher yield! It also removes any risk of  your tests being modified and re-purposed for use on other product lines. 

You can even go one step further and configure a sequence to only run on a particular SoundCheck system, or block of system hardware keys. This is also simple to configure – either by entering the hardware key laser IDs, or importing a list from a CSV file. Locking a sequence to your particular systems adds another layer of security, and gives you additional confidence in your test set-up, as you know your measurements are being made on a genuine SoundCheck system with all the capabilities needed to successfully run the sequence.

And, just one final word of caution… all sequence protection data is encrypted for maximum security, so make sure you have that password in a safe place! 

This feature is available in SoundCheck 21 and higher. Check out the user manual or ask your sales engineer for additional information.

100 Things #78: Evaluating Stereo Soundfields using Time Selective Response

Time selective response in SoundCheck can be used to evaluate a stereo sound system’s localization and envelopment characteristics. By calculating the interaural level differences using a head and torso simulator, SoundCheck can measure and display the sound localization. SoundCheck can measure both the interaural level difference, and interaural cross correlation, all in a single sequence.

Evaluating Stereo Soundfields using Time Selective Response

Check out our pre-written Stereo Soundfield Parameters sequence

Try time selective response for yourself! This complete sequence measures parameters such as Interaural level difference (ILD) and interaural cross-correlation (IACC) using a Head and Torso Simulator (HATS). The spectrum is measured at each ear and calculates interaural level differences (ILD), spectral balance, delay differences, and interaural cross-correlation (IACC). The measurements are made using different time windows, so that the direct, early, late or total parts are separated.

Video Script:

Time Selective Response (TSR) has been part of SoundCheck since 2001. It’s frequently used to make reflection-free measurements of loudspeakers in ordinary rooms.

But did you know it can also be used to evaluate localization and envelopment of stereo sound systems? Let’s listen to a full stereo music excerpt in which the locations of the instruments are easily heard. For the best listening, use either stereo headphones or a pair of speakers spaced apart.

(Audio: Full stereo example.) 

The sound of the band is well spread from left to right, and the soloist is clearly in the center. Next, listen to the same music, where the sound of the band is concentrated in the middle:

(Audio: Narrow stereo example.) 

Using TSR and simple post-processing steps, we can measure the Interaural Level Differences (ILDs), which are strongly related to stereo spread and localization.

Now listen to the same music as it might sound in a concert hall where you are enveloped by the reflections and reverberation of the hall:

(Audio: Full stereo with reverb example.) 

Using TSR and some advanced post-processing steps, we can measure the Interaural Cross Correlation (IACC), which is strongly related to envelopment or a sense or spaciousness.

The SoundCheck measurements start with a log sweep played first to the left channel, (Audio: TSR sweep L , under)

…then to the right channel, (Audio: TSR sweep R , under)

…and finally, to both channels. (Audio: TSR sweep L and R , under)

For each sweep, the frequency responses from the HATS ears are analyzed using Time Selective Response. These frequency responses are used to calculate the Interaural Level Differences, or ILDs.

The uncorrelated ILDs indicate the ability of the sound system to produce directional effects. ILD’s are mostly related to the perceived speaker locations.

The direct ILDs without reflections, shown in the dotted curves, are the most important. The large difference indicates very good localization. The solid lines, including all reflections, indicate that the room tends to reduce the direct localization effect a little. 

The frequency responses are again used to calculate the Interaural Cross Correlation (IACC).

IACC is most important above 500Hz.

The yellow curve is based on the direct sound when both speakers are playing the same signal. It is close to 1, indicating central location and little sense of envelopment.

The green curve is based on the direct responses, without reflections, when the speakers are playing different sounds. It is between 0 and 1, indicating some envelopment.

The blue curve is based on the total responses, including reflections. It is between 0 and 1, but a bit lower, indicating additional envelopment provided by the room.

Using TSR analysis, SoundCheck can measure Interaural Cross Correlation (IACC) and Interaural Level Difference (ILD). When interpreted together, they objectively describe many of the spatial characteristics of sound systems. The pre-written sequence “Stereo Soundfield Parameters,” available from Listen, puts all this and more together in an easy-to-use package. Check out the Listen website to learn more.

100 Things #77: Using Confidence Limits for Sequence Speed and Accuracy

SoundCheck’s Measurement Confidence is a powerful way to qualify factors that may influence measurements, like noise, settling time, latency, and quantization. Using the confidence limits feature in the analysis step, SoundCheck can display measurements along with any measured discrepancies. A sequence’s stimulus can be edited with tons of flexible options, including increasing both cycle count and minimum duration of a Stweep’s steps. Adjusting these stimulus parameters can fine tune your sequence, yielding high measurement confidence.

Using Confidence Limits for Sequence Speed and Accuracy

Learn more about using confidence limits in SoundCheck

Our Working From Home with SoundCheck video series features an even more in-depth demonstration of confidence limits, diving into the trade off between measurement speed and accuracy.

Video Script:

There are many factors that affect measurement accuracy. Noise, settling time, latency, quantization, sampling and other impediments, all affect the quality of your measurements.  SoundCheck’s powerful ‘Measurement Confidence’ tool helps you assess how these factors impact your measurements and helps you fine-tune any trade-offs between speed and accuracy. This feature is found in the HarmonicTrak analysis editor on the Distortion tab.

Let’s focus on noise as the source of our measurement error. SoundCheck’s HarmonicTrak algorithm uses FFT analysis to measure the levels for each step of a stepped sine sweep. The shorter the duration of a step, the larger the width of the FFT filter around its center frequency which allows a greater amount of noise to collect in the filter band.  Noise adds to the sinewave and if you measure it 10 times, you’ll get 10 slightly different results. The standard deviation of the 10 measurements is called the standard error which is directly proportional to the noise collected in the FFT filter and to the duration of the step. By evaluating the level of the noise present in the FFT, SoundCheck is able to give you the standard error at each frequency.

Additionally, SoundCheck can produce limits within which you can expect the true value to lie. These are called Confidence Limits and there’s even a sequence included in your Soundcheck installation which demonstrates this feature. Let’s take a look.

The sequence uses three different Stweep configurations to show how the Confidence feature works. SoundCheck’s stimulus editor gives us precise control over the duration and number of cycles per step in our Stweep. In this example sequence, the first stimulus is configured so that each step contains 3 cycles. In the second stimulus, each step contains 10 cycles and in the third stimulus we add a minimum duration value of 10 ms in addition to the 10 cycle requirement. Let’s run the sequence and take a look at the results.

In sweep 1, the confidence limits are quite wide and drop off dramatically at the low frequency and high frequency where the signal to noise decreases due to the lower levels. It’s no surprise, considering the small number of cycles per step. Increasing the minimum number of cycles to 10 dramatically improves the results.  Confidence is overall very good with the exception of the very high frequencies.  In the last sweep, by introducing a minimum duration requirement of 10ms, we can see a further improvement at high frequencies since we are extending the duration of the steps at the highest frequencies.

I hope that this demo gives you a taste of what you can do with the Measurement Confidence feature in SoundCheck.  There’s a more extensive demo of this feature in our Working From Home with Soundcheck video series and further details in the SoundCheck user manual.

Learn more about SoundCheck features and functionality.

100 Things #76: Using SoundCheck to Test Communications Devices

Modern devices let us communicate with each other more than ever, in new and exciting ways. Telecommunications devices have evolved, so have the methods to test them. Today’s communications standards test the functionality of devices connected via USB, Bluetooth, and the cloud. SoundCheck facilitates testing these devices with the ability to connect to multiple devices with different hardware connectivity. Configuring SoundCheck to run these often complex test sequences saves time, allowing the whole test to run without operator interruption.

Using SoundCheck to Test Communications Devices

Watch more

Our full Communications Testing seminar features Listen president Steve Temme and Communications Consultant John Bareham giving a deep dive on tests like Doubletalk, TIA-5050, POLQA, TIA-920B

Learn more about using SoundCheck for communications tests

Our main page on communications testing details the benefit of using SoundCheck for telecommunication tests, possible measurements, communications test configurations, and pre-written sequences testing to standards like TIA 920-B, ETSI ES 202 396-1, and more.

Video Script:

You know that SoundCheck measures acoustic parameters, but did you know that you can also implement industry-standard tests on a wide range of communications devices?

Speech communication always involves talking and listening. Today we frequently communicate using various consumer electronic devices such as headphones, hearables, smart glasses, watches, smart speakers, intercom systems, 2-way radios and, of course, smartphones. 

To accommodate this shift, industry-standard communications tests have evolved from tests on old-fashioned wired “telephones” to more sophisticated tests on these more complex devices. These devices also connect in different ways, including USB, Bluetooth, and the cloud. 

Although it’s often not required to test these devices to industry standards, it’s very worthwhile to make these measurements from a product performance perspective, especially if you anticipate needing to pass 3rd party verification.

With SoundCheck, you can measure voice quality performance to TIA, ETSI and other standards. It’s easy to test via direct connection, USB, or a Bluetooth interface. Seamless integration with your computer’s audio also makes it easy to route signals between the device, the cloud, and your computer for open loop measurements.

Several features recently introduced in SoundCheck facilitate more advanced communications tests, such as Active Speech level, RMS level versus time, silence stimulus step and histogram post-processing steps. These support measurement of Doubletalk, echo detection, background noise evaluation, and more. The optional  POLQA module also enables speech quality analysis using the POLQA algorithm directly within SoundCheck.

Standardized communications test sequences can be very complex, and SoundCheck contains all the functionality to create these tests. We also offer shortcuts with our pre-written test sequences for TIA-920-B, TIA-5050, and Doubletalk to ITU-T P.502 and ETSI TS 126132. These complex test sequences automatically implement entire tests according to the standards, saving considerable development time, and ensuring that measurements are made correctly.

All these tests are fully demonstrated. in Listen’s communications seminar – check it out to learn more.