Tag Archive for: seminar

Smart Device Testing Seminar

Testing smart devices such as smart speakers, hearables, watches and more involves a combination of tests from many different application areas, ranging from simple transducer tests to open loop tests, Bluetooth measurements, voice activation tests, telecoms standards, hearing aid measurements and more. In this demo-focused seminar, we demonstrate how SoundCheck makes all the measurements you need throughout the entire smart device design process from component selection to pre-qualification testing.

Smart device testing demonstrations include:

  • Component tests: MEMS microphone measurement, directional microphone measurement, speaker evaluation
  • Prototype tests – open loop speaker test on a smart speaker, open loop microphone test on a smart speaker, Bluetooth hearables test, headphone Active Noise Cancellation (ANC) Measurement
  • Background Noise Tests: calibration, using pub noise to evaluate a microphone’s ability to reject background noise

Presenters: Steve Temme, Mark Latshaw, Steve Tatarunis
Duration: 48 Mins

Smart Device Measurement Resources

This seminar was originally broadcast on June 6th 2023. The recording below does not include the live Q&A at the end for attendee confidentiality reasons. However, several links to additional resources were provided during the Q&A session, and these are provided below.

  1. Internally routing audio: Open Loop microphone testing requires audio to be routed into SoundCheck. We recommend:
    1. Virtual Audio Cable for Windows: https://vac.muzychenko.net/en/index.htm
    2. Soundflower for Mac: https://github.com/mattingalls/Soundflower
  2. In response to a question about whether haptic feedback could be measured in a smartwatch, we shared a SoundCheck test sequence for measuring haptic feedback: https://www.listeninc.com/products/test-sequences/free/linear-motor-test-sequence/
  3. We touched briefly on communications audio tests when smart speakers are used as hands-free devices. To learn more about Communications Testing techniques and standards, please see our Communications Testing Seminar.
  4. Similarly, in answer to a question about testing automotive infotainment systems, we shared our Automotive audio testing seminar

More about how to Measure Smart Devices

Check out our main page on Smart Device Testing, which includes links to test sequences, relevant products and more.


Introducing Enhanced Loose Particles (eLP)

Watch our launch seminar for Listen’s latest algorithm, enhanced Loose Particles (eLP). This new algorithm significantly improves production line transient distortion measurement. It offers high accuracy, easy correlation to human perception, and identifies transient distortion artifacts separately from harmonic distortion for easy troubleshooting. It’s also ideal for identifying rattling buttons in audio devices, and automotive Buzz, Squeak and Rattle (BSR) measurements. This new algorithm is based on original research, and uses techniques not previously used for distortion measurement. Check out this demonstration and detailed explanation of how this algorithm works by Listen president Steve Temme.

Introducing Enhanced Loose Particles

Read on to learn more

For all things Enhanced Loose Particles including listening examples, published articles, and details of the eLP methodology, check out our Enhanced Loose Particles page.

Listen’s new enhanced Loose Particle algorithm offers accurate transient distortion measurements, even in the presence of background noise. This algorithm is highly accurate, as well as easy to configure and set limits. Results are easily correlated to audibility by listening to the loose particles in the recorded waveform.

This algorithm uses the same time envelope analysis as our pioneering (2004) Loose Particles algorithm, but rather than filtering and counting pulses, additional analysis is applied to measure the prominence, or impulsiveness, of the detected artifacts. The algorithm calculates the prominence of each loose particle event in the waveform by comparing the magnitude of a peak relative to the surrounding minimums, which reflects the impulsiveness of the artifact more accurately than the absolute magnitude of the peaks.  A user-defined prominence threshold determines the level at which the peak will be counted, and a user-defined count of events over the time window determines the pass/fail threshold.

Objective results obtained by this method are easily correlated to subjective analysis as you can listen to the recorded waveform with the fundamental removed, hearing only the loose particles. This enables the prominence threshold to easily be set based on defect audibility.

This analysis method is inherently reliable in a factory environment as external background noise events typically only occur once or twice during a measurement, whereas many loose particle transients will occur during the same timeframe. The event count is user-determined, and is set according to the background noise in the measurement environment. Prominence threshold and loose particle count are the only parameters that the user needs to define, so limit setting is simple, well correlated to audibility, and can be configured to give reliable results even when background noise is present.

External Control of SoundCheck Seminar

SoundCheck has led the way in production line audio measurement for over 25 years with its sophisticated suite of audio measurement algorithms that offer precise measurement, fast throughput, excellent noise immunity, and world-class reliability. However, many audio manufacturing factories are moving towards large, highly customized, integrated test configurations to evaluate products, not only for audio integrity, but often video, visual and other performance defects. This seminar explains how external control capability brings the advantages of SoundCheck into your automated test environment using any programming language compatible with TCP/IP  including C, C+, Python, LabVIEW and more.

External Control demonstrations include:

  • Enabling TCP-IP in SoundCheck, and an overview of commands
  • Using external control to open up and run a SoundCheck sequence using a python script, and returning data for use in any application
  • Changing test parameters via external control, so that test procedures can be simplified by adapting test conditions on the fly for different products
  • Loading, playing and controlling volume of  a test signal on a DUT  using a custom step in a SoundCheck sequence.
  • Using external control to automatically equalize wave files loaded into SoundCheck via TCP/IP
  • Using MATLAB with SoundCheck

Presenters: Mark Latshaw, Pranav Swaroop
Duration: 30 Mins

More about External Control of SoundCheck

The SoundCheck manual includes a full list of TCP/IP commands for use with SoundCheck, and an explanation of the JSON formatted return.

Learn more about SoundCheck for production test.

Resources for controlling SoundCheck with programs externally

To learn more about the Python programming language used in this seminar, check out the official Python website.

To learn more about MATLAB by MathWorks, check out the official MATLAB website.

Automotive Audio Measurements (Seminar): Frequency Response, Max SPL, Buzz, Squeak & Rattle

In this practical online seminar, Steve Temme demonstrates in-car measurement of frequency response, Max SPL, and Buzz, Squeak and Rattle using a Bluetooth connection. He discusses considerations such as physical setup, infotainment system controls and the measurement parameters. We then discuss connectivity for automotive testing, explaining and demonstrating the various connectivity options including USB drive, Bluetooth and A2B bus. Finally, we take a look at some of the other audio measurements that you can make using SoundCheck, for example active noise cancellation and voice assistance readiness.

Automotive Audio testing demonstrations include:

  • Frequency Response
  • Max SPL and Max SPL Spectrum
  • Buzz, Squeak & Rattle
  • Connectivity Options – USB, Bluetooth, A2B bus
  • ANC and Voice assistance readiness

Presenters: Steve Temme
Duration: 32 Mins

Automotive Audio Measurement Resources

This seminar was originally broadcast on July 21st 2022. The recording below does not include the live Q&A at the end for attendee confidentiality reasons. However, several links to additional resources were provided during the Q&A session, and these are provided below.

  1. Test sequence for in-car audio measurements. This sequence measures the impulsive distortion, frequency response, and maximum sound pressure level of a vehicle
  2. An article by Steve Temme on automotive Max SPL measurements. Originally published in VoiceCoil magazine, June 2022.

More about how to Measure Automotive Audio

Check out our main page on Automotive Audio Testing, which includes links to test sequences, relevant products and more.

Learn more about Connecting to Automotive Infotainment Systems

Maximum SPL measurements in cars

Buzz, Squeak and Rattle measurements

AES Technical Committee on Automotive Audio. Listen, Inc. works closely with this group to ensure that our measurement capabilities align with the measurements recommended by the AES.

Virtual Instruments Seminar

Virtual instruments, included in SoundCheck, are a cost-effective and portable software-based alternative to hardware instrumentation, ideal for making quick measurements or viewing device behavior in real time. In this educational seminar, Les Quindipan walks through a demonstration of the virtual instruments in SoundCheck, showing off some of their lesser-known capabilities. These include the signal generator, multimeter, oscilloscope/spectrum analyzer, real time analyzer, frequency counter and distortion analyzer. The strip chart recorder, which expands the capability of these instruments to record measurements over a period of time, are also discussed.

Virtual Instrument testing demonstrations include:

  • What are Virtual Instruments, and how to use them in SoundCheck
  • How instruments use existing SoundCheck signal paths and calibrations
  • Tour of individual instruments
  • Using multiple instruments and saving Virtual Instrument Configuration Files (or .vic files)
  • Explore using Virtual Instruments in a SoundCheck sequence
  • Practical applications of SoundCheck Virtual Instruments

Presenters: Les Quindipan
Duration: 30 Mins

Virtual Instrument measurement resources

Check out our main page on SoundCheck Features and Functionality for more detail on all of SoundCheck’s audio test and measurement capabilities.

The Virtual Instrument example sequence included in the SoundCheck installation is a great starting point for working with virtual instruments. The sequence automatically performs measurements with various virtual instrument configurations with operator message details about each configuration. This sequence can be used as a template sequence to build a custom test sequence.

More about testing with Virtual Instruments

The Multi-RTA virtual instrument in SoundCheck features true recursive digital filtering, and conforms to the ANSI S1.11-2004 standard.

Production Testing Seminar

In this short seminar, Les Quindipan explores the use of SoundCheck for end-of-line electroacoustic production testing. He discusses typical test configurations and the type of measurements that can be made, how to set pass/fail limits and how to optimize tests for high throughput.

He also explains how SoundCheck is easily scaled for high volume electroacoustic testing, with such features as external control via another program and auto-saving data to databases, and how SoundCheck’s capabilities are easily expanded through the use of custom steps to control all types of devices and test fixtures.

This seminar will interest anyone considering a production line implementation of SoundCheck, or curious as to how to transition R&D measurements to fast and effective end-of-line test.

Production Testing demonstrations with SoundCheck include:

  • How to scale for high volume electroacoustic production testing, saving time and money
  • Typical audio measurements used in production testing
  • Production test setups
  • Optimizing test times and accuracy
  • Setting pass and fail limits in a test sequence
  • Auto-saving data
  • Custom Step Applications
  • Controlling SoundCheck externally from another program

Presenters: Les Quindipan
Duration: 18 Mins

More about Electroacoustic Production Testing with SoundCheck

A read on about at using SoundCheck for Production, as well as the transition of testing in a production environment from SoundCheck in the R&D Lab.

Take a closer look at the hardware used in this seminar, the AmpConnect 621.

Resources for Production Testing with SoundCheck

Learn more about the  WATS test data management system referenced in the video.

Basic Loudspeaker Testing Seminar

This introductory seminar is aimed at anyone new to audio measurement, specifically loudspeaker testing. It begins with an introduction to the basic design of a loudspeaker, including how a typical loudspeaker works. Various loudspeaker measurements are explained, such as frequency response, distortion, sensitivity, phase/polarity and impedance, and how they might offer indications as to potential defects in a speaker. Typical test configurations for both R&D and end-of-line production test are shown. A complete speaker test is demonstrated, using SoundCheck and our free Loudspeaker complete test sequence. This includes setting up software and hardware, calibrating and configuring the test (e.g. setting pass/fail limits) and a discussion of the results.

Basic Loudspeaker Testing demonstrations include:

  • Anatomy of loudspeaker design
  • How a loudspeaker works
  • Loudspeaker test setup with SoundCheck
  • Considerations when testing a loudspeaker in an R&D versus production environment
  • Critical measurements like frequency response, sensitivity, phase, polarity, impedance, and distortion

Presenters: Les Quindipan
Duration: 22 Mins

Basic Loudspeaker Testing measurement resources

Complete End-of-Line Speaker Test: This free test sequence performs a full suite of basic measurements for a loudspeaker, featuring our two new perceptual distortion metrics. ePRB, or enhanced Perceptual Rub & Buzz is used to detect and differentiate audible distortion from total distortion. eLP, or enhanced Loose Particles, performs transient distortion measurements even in the presence of background noise.

More about Basic Loudspeaker Measurement

Johan Segeborn’s video “How Does A Speaker Work?” is an excellent reference for loudspeaker behavior.

Bluetooth Testing Seminar

Les Quindipan of Listen, Inc. and Kristopher Hett of Portland Tool & Die demonstrate Bluetooth testing with a variety devices, test parameters, and testing considerations. Kris Hett introduces the Portland Tool & Die Bluetooth interfaces that are used to connect the device under test to the measurement system. He discusses the technical specifications, and explains the differences between these and other types of Bluetooth interfaces. Les Quindipan then demonstrates how these have been fully integrated into SoundCheck for simple plug and play operation, and how they can be used in test sequences. He also highlights some of the algorithms included in SoundCheck that overcome Bluetooth-induced time delays, thus enabling these devices to be tested in a similar way to their wired counterparts. A complete test on a Bluetooth speaker and a Bluetooth Headset is demonstrated.

Seminar demonstrations include:

  • Overview of Portland Tool & Die Bluetooth interfaces features and functionality
  • Portland Tool & Die software control integration with SoundCheck
  • SoundCheck configuration and calibration for testing Bluetooth devices
  • Software control of Portland Tool & Die devices within a SoundCheck sequence
  • Demonstrations of sequence measuring Bluetooth headsets and speakers

Presenters: Les Quindipan, Kristopher Hett
Duration: 30 Mins

Bluetooth testing Resources

  • Our sequence library contains many ready-to-run sequences for testing Bluetooth devices, available for download for no charge.

More about testing Bluetooth devices

Check out our main page on Bluetooth Headphone Testing, which includes links to test sequences, relevant products and more.

Advanced Microphone Measurements Part 2

Listen’s Support Manager, Steve Tatarunis, discusses some of the more advanced aspects of microphone measurements. This is an expansion of material covered in the Basic Microphone Testing webinar, and part two of the full advanced microphone measurements seminar. Advanced Microphone Test part 1 shows microphone measurements like polar plotting, open loop, active/passive noise rejection, and more. This seminar is of interest to anyone testing microphone characteristics, both in an R&D and production line environment. The tests featured in this seminar can be used both at component level, whether selecting microphones for devices or component QC, or these tests can be performed on finished products like smartphones, smart speakers, and more.

Seminar topics include:

More advanced aspects of microphone testing including:

  • Phase
  • Open loop microphone testing for voice activated devices such as smart speakers, automotive audio, etc.
  • Intermodulation distortion
  • Advanced hardware and test configurations for measuring microphone arrays
  • Beamforming with broadside and endfire arrays
  • Measuring MEMS devices frequency, sensitivity and power supply rejection (PSR) performance

Presenters: Steve Tatarunis
Duration: 40 Mins

Advanced microphone measurements resources

SoundCheck comes with many pre-written sequences including the sequences demonstrated in this seminar including the microphone test sequences for measuring microphone self noise, microphone substitution, frequency response and sensitivity, and open loop. Additionally, we offer the sequences featured in this seminar measuring digital MEMS microphones and microphone intermodulation distortion in our sequence library for download. Along with the sequences featured in this seminar, our sequence library is full of additional pre-written sequences for basic microphone measurement.

More about advanced microphone measurements

Check out our main page on Microphones, which includes links to test sequences, relevant products and more.

Simulated Free Field Measurements Without an Anechoic Chamber

In this online seminar, Steve Temme explains how to use simulated free field measurements to provide accurate free-field measurements across the entire audible frequency range without an anechoic chamber. This enables measurements that would usually be made in an anechoic chamber to be made in a regular lab or even home office – a valuable capability when so many are currently working from home.

This measurement method, which has been available in SoundCheck since 2001, measures the near-field response at low frequencies and the time-windowed far-field measurement at higher frequencies, and splices them together to provide the response over the entire frequency range.

This seminar explains the acoustics and mathematics behind this method, demonstrates the test procedure with the pre-written (and available free of charge) SoundCheck test sequence, and show how the results correlate to measurements made in an anechoic chamber.

Seminar topics include:

  • Discussion of sound paths and reflections and explaining the mathematic and acoustic principles behind simulated free field measurement techniques
  • Test set-up that can be used to measure this
  • Demonstration of the “Splice” sequence and measurements in SoundCheck
  • Correlation to results made in an anechoic chamber and manufacturer’s published data

Presenters: Steve Temme
Duration: 31 Mins

Resources for simulated free field measurements

Steve Temme and Christopher Struck authored a whitepaper for the AES on simulated free field measurements, available as PDF for further reading.

Our pre-written sequence demonstrated in this seminar for measuring the anechoic response of a loudspeaker without an anechoic chamber, or “Splice” sequence, is available for download from our sequence library

Check out our main page on Loudspeakers and Microspeakers, which includes links to test sequences, relevant products and more.