Tag Archive for: open loop testing

SoundCheck 17 New Features Video

In this short video, sales engineer Les Quindipan gives a brief overview and demonstration of the new features and functionality of SoundCheck 17, including the new level and cross-correlation trigger, average curve/waveform post-processing functionality, new color palettes, save to MATLAB option, and more.

Triggered Record Using Chirp Trigger and WAV File (Version 17 and later)

This test sequence demonstrates SoundCheck’s Triggered Record – Chirp Trigger function for open loop testing of devices without analog inputs such as smart speakers, wearables, smart home devices, tablets and cellphones.  A stimulus WAV file is created in SoundCheck and transferred to the device under test, where it is played back and the response recorded in SoundCheck as if the stimulus were played directly from SoundCheck. The Acquisition step is triggered by the chirp in the stimulus file. Chirp triggers are more robust than level and frequency triggers which are susceptible to false triggering due to background noise.

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SoundCheck 16.1 Released – New Frequency Trigger for Open Loop Testing

Listen is excited to announce the release of SoundCheck 16.1. This minor release, which contains some exciting new features, is available free of charge to all registered users of SoundCheck 16.0.

Most significant is the inclusion of a new frequency trigger. This allows frequency-based triggering of acquisition from an external source using a pilot tone at the beginning of a test sweep. This allows for improved accuracy over previous level-based triggering when capturing responses from a device where you don’t have direct access to the microphone or speaker, especially in noisy environments. This technique optimizes open loop test methods for smart speakers and other voice-controlled devices such as smart phones, robots, automotive audio, smart thermostats, hearables and more. You can view a short video explaining this feature here:

 

We also have a free measurement sequence using the frequency trigger that can be downloaded from our website so that you can test it out right away! View Sequence.

SoundCheck now also fully integrates with the Mentor A2B interface for testing automotive audio connected via the Analog Devices A2B digital bus. The Mentor Analyzer, which handles the transmission of signal in to and out of the bus, is viewed as an ASIO interface by SoundCheck, enabling SoundCheck to read/write to the device and therefore analyze any transducer connected to the A2B bus. A custom VI permits control of the Mentor A2B interface configuration via SoundCheck. This means that it can be controlled from within a SoundCheck sequence, for example loading configurations and starting/stopping ASIO streams. This makes it an ideal R&D or production line test solution for automotive audio, or for anyone testing transducers connected via A2B bus. More.

Also available (additional cost) with this new release are two optional sequences – background noise simulation to the ETSI ES 202 396-1 standard, and the TIA-920B dual-bandwidth telephone test standard.

The background noise simulation sequence (part number 3121) is a cost-effective alternative to dedicated background noise generation systems. It calibrates a 4.1 speaker array to conform with the ETSI ES 202 396-1 Standard, providing an equalized, calibrated playback solution to stress devices in a standardized and repeatable way. The sequence includes a library of real world binaural recordings from the standard, and custom or user-defined binaural recordings may also be used. Applications of this sequence include evaluating ANC, noise suppression, voice recognition testing, SNR optimization of microphones, beamforming directionality studies of microphone arrays and more. More.

The TIA-920B sequence (part number 3111) tests to the TIA-920B dual-bandwidth standard that applies to both narrowband (NB) and wideband (WB) devices. It also allows a choice between Free Field (FF) and Diffuse Field (DF) as the Listener Reference Point (LRP). The current release measures digital communications devices with handset features, according to TIA-920.110-B and speakerphones, according to TIA-920.120-B. Support for headset measurements, according to TIA-920.130-B will be added in a future release. More.

Open Loop Microphone Testing

This sequence demonstrates the two most common microphone measurements, frequency response and sensitivity, on a microphone embedded in a recording device. Typically, when measuring a microphone the response of the device can be captured simultaneously with the stimulus. However, with devices such as voice recorders and wireless telephone forming a closed loop can be cumbersome or impossible. This sequence demonstrates how to measure such a device by recording the signal on the device under test, transferring that recording to the computer running SoundCheck and then using a Recall step to import the recorded waveform and analyze it.

This specific sequence, v4, is an improvement on the prior versions. The v1 release required that the audio file containing the recorded response waveform be manually windowed outside of SoundCheck before being analyzed. The v2 release utilized a new feature in SoundCheck 14, using values from the memory list to semi-automatically trim the waveform before analysis. The v3 release completely automated waveform editing through the use of an intersection level and windowing post processing steps. Currently the v4 release uses the new Auto Delay+ algorithm, exclusive to SC18 and beyond. Auto Delay+ is capable of detecting and accounting for delays of -0.5 seconds to any positive delay, nullifying the need for windowing steps in the sequence. If you are interested in learning more about this algorithm please refer to the Analysis section of the SoundCheck manual.

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