Test class
Test
Testing Voice-Controlled & Smartphone Integrated Infotainment Systems
A tutorial and accompanying paper that was presented at the AES Automotive Conference, Sept 11-13, 2019, Neuburg an der Donau, Germany.
Voice-controlled and smartphone integrated vehicle infotainment systems are notoriously complex to test. They have numerous connections from wired to wireless and contain much signal processing, both on the record and on the playback side. This means that their characteristics change according to ‘real world’ conditions of the vehicle’s environment, including cabin acoustics and background noises from road, wind and motors. Furthermore, their multifunctional nature means that there are many aspects of the device that may need to be tested, ranging from voice recognition to music playback and operation as a hands-free telephone. Due to their complex non-linear use cases, these devices often need to be tested at different levels and different environmental conditions.
This tutorial offers practical hands-on advice on how to test such devices, including test configurations, what to measure, the challenges of making open-loop measurements, and how to select a test system.
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.
TIA-920-B Sequence for Measurement of Narrowband and Wideband Digital Phones
This sequence tests to TIA 920-B, a comprehensive US 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 of this sequence 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.
This module is a large structured set of sequences and subsequences which perform all the measurements. Curves and values are shown on the screen, tolerance checks are performed, and data is saved to Excel spreadsheet files. Completely prompted sequences for calibration of all the transducers are included. After a one-time setup with a sound card and other user-specific interfaces, the sequences are automatic. They run by simply selecting, pressing start, and following prompts where user interaction with the device under test is required. The sequence works with approved sound cards for connection to the transducers. Windows audio devices such as USB headsets work directly with SoundCheck®. VoIP softphones also work with SoundCheck, by means of a recommended third-party Windows audio application.
Korea Headphone Seminar
Over 150 people attended the Listen, Inc./G.R.A.S. headphone seminar in Seoul on Tuesday March 6th, where Steve Temme, Peter Wulf-Andersen, Dr. Sean Olive and Prof. Lee spoke to a packed room about headphone measurement, perception and design and tuning. It was a great event and exciting to meet so many of Korea’s top audio design engineers. Thank you for coming! And of course a huge thank you to our very special guest speakers, Dr. Olive and Prof. Lee.
Videos of the event (in English and Korean) can be viewed using the links below (videos will open in a new tab).
Peter Wulf-Andersen – G.R.A.S.: https://youtu.be/sTZpShVDaoI
Steve Temme – Listen, Inc.: https://youtu.be/35TtshAENdo
Prof. Lee – New Media Communication Joint Institute of Seoul National University: https://youtu.be/mhLW03PvLmw
Dr. Sean Olive, Harman International: https://youtu.be/B8cNf0Q3tNs
Photo Gallery
-
- Listen Presentation
-
- Steve Temme, Listen, Inc.
-
- Peter Wulf-Andersen, G.R.A.S.
-
- Dr. Sean Olive, Harman International
-
- Prof. Lee, New Media Communication Joint Institute of Seoul National University
-
- G.R.A.S. Presentation
-
- Demos
-
- Presenters and organizers
-
- Presenters and attendees
Headphone & Headset Measurements – Seoul, Korea – March 6, 2018
Presented by:
Due to popular demand, we are now holding our headphone testing seminar in Seoul!
Learn about the latest in headphone test systems and methods from design to EOL Test. Industry experts Steve Temme (Listen, Inc.) and Peter Wulf-Andersen (G.R.A.S.), as well as guest speakers Dr. Sean Olive (Harman International) and Prof. Lee (New Media Communication Joint Institute of Seoul National University) will discuss test equipment (ear couplers, test fixtures, test software and hardware) and demonstrate practical test setups for both R&D and QC headphone testing. It will cover in-ear monitors, Bluetooth, lightning/USB, noise-cancelling and high resolution headphones, in addition to conventional analog headphones. You can even measure your own headphone using our equipment in the hands-on session. Please see the full agenda below.
There is no charge for this one-day seminar. Space is limited, so please RSVP today.
Location and Dates:
Seoul: Tuesday March 6th, 2018. Korea National University, 1 Gwanak-ro, Gwanak-gu, Seoul.
See what people are saying about this event (we presented similar last year in the US)
Agenda (9am-4pm)
- Introduction
- Overview of Headphone Test Systems and tools
- Traditional tools vs. modern consumer demands
- Introduction to head and ear related terminology and definitions.
- Historical perspective and background for the tools and standards used today.
- Limitations vs. Possibilities in term of the measurement capabilities. How does that relate to the modern challenges with Bluetooth and ANC related testing tasks?
- Tools for Next Generation Headphone Testing
- Solutions to some the challenges addressed above.
- Examples based on products and measurements.
- What about frequencies above 20kHz? Science or marketing? Measurement Consistency – Development vs. Production
- Progress in measurements from Head and Torso Simulator (KEMAR) to Production Test Fixture (45CC – flat plate). How the different components affect the measurements:
- Software and hardware for headphone testing including typical headphone measurements and test setups
- Traditional tools vs. modern consumer demands
- Practical examples of headphone measurements on.
- Analog Headphones
- Bluetooth Headsets
- ANC Headphones
- Lightning/USB Connected Headphones (using triggered recordings)
- Hi-Res Headphones
- In-ear monitors
- Measurements including:
- Frequency Response relative to a target response
- Left/Right tracking
- Impedance
- Noise attenuation
- Distortion including Non-Coherent Distortion
- Standards including Max SPL EN-50332 & IEC-60268-7
- Design & sound tuning of earphones (Guest Speaker Prof. Lee, New Media Communication Joint Institute of Seoul National University)
- Headphone Design: Perception and Measurement of Headphones – What is the Preferred Target Response? (Guest Speaker: Dr. Sean Olive, Harman International)
- Hands-on testing: Bring your own device and test it using one of our measurement setups
Headphone & Headset Measurements – Chicago and Boston Dates
Presented by:
Due to popular demand, we are now holding our headphone testing seminar in Chicago and Boston!
Learn about the latest in headphone test systems and methods from design to EOL Test. Industry experts Steve Temme (Listen, Inc.) and Peter Wulf-Andersen (G.R.A.S.), as well as guest speaker Dr. Sean Olive (Harman International) will discuss test equipment (ear couplers, test fixtures, test software and hardware) and demonstrate practical test setups for both R&D and QC headphone testing. It will cover in-ear monitors, Bluetooth, lightning/USB, noise-cancelling and high resolution headphones, in addition to conventional analog headphones. You can even measure your own headphone using our equipment in the hands-on session. Please see the full agenda below.
There is no charge for this one-day seminar and lunch will be provided. Space is limited, so please RSVP today.
Locations and Dates:
Chicago: Friday October 13th, DoubleTree by Hilton Hotel Chicago Wood Dale-Elk Grove, 1200 N Mittel Blvd, Wood Dale, IL 60191
Boston: Monday October 16th, Hilton Garden Inn, 450 Totten Pond Rd, Waltham, MA 02451 NOTE: THIS VENUE HAS CHANGED. DUE TO HIGH DEMAND FOR THIS SEMINAR WE HAVE HAD TO MOVE IT TO A LARGER VENUE. Note that this is 2 days before the start of the AES show in New York – a short flight or 3.5 hour train ride away. Consider combining this informative seminar with your AES travel!
See what people are saying about this event (we presented similar earlier in the year on the West Coast)
Agenda (9am-4pm)
- Introduction
- Overview of Headphone Test Systems and tools
- Traditional tools vs. modern consumer demands
- Introduction to head and ear related terminology and definitions.
- Historical perspective and background for the tools and standards used today.
- Limitations vs. Possibilities in term of the measurement capabilities. How does that relate to the modern challenges with Bluetooth and ANC related testing tasks?
- Tools for Next Generation Headphone Testing
- Solutions to some the challenges addressed above.
- Examples based on products and measurements.
- What about frequencies above 20kHz? Science or marketing? Measurement Consistency – Development vs. Production
- Progress in measurements from Head and Torso Simulator (KEMAR) to Production Test Fixture (45CC – flat plate). How the different components affect the measurements:
- Software and hardware for headphone testing including typical headphone measurements and test setups
- Traditional tools vs. modern consumer demands
- Practical examples of headphone measurements on.
- Analog Headphones
- Bluetooth Headsets
- ANC Headphones
- Lightning/USB Connected Headphones (using triggered recordings)
- Hi-Res Headphones
- In-ear monitors
- Measurements including:
- Frequency Response relative to a target response
- Left/Right tracking
- Impedance
- Noise attenuation
- Distortion including Non-Coherent Distortion
- Standards including Max SPL EN-50332 & IEC-60268-7
- Headphone Design: Perception and Measurement of Headphones – What is the Preferred Target Response? (Guest Speaker: Dr. Sean Olive, Harman International)
- Hands-on testing: Bring your own device and test it using one of our measurement setups
Lightning Headphone Test (Open Loop Test)
This sequence tests a stereo headphone connected to a portable audio device such as a mobile phone or MP3 player. It is particularly useful for testing headphones with proprietary connectors such as the Lightning connector which otherwise can’t be tested in a conventional “closed loop” test configuration.
The test stimulus is created in SoundCheck, saved as a WAV file and loaded on to the portable device for playback. Both left and right earphones are measured simultaneously using a continuous log sweep from 20 Hz to 20 kHz. The sequence uses a short 1 kHz tone, pre-pended to the normal test stimulus to automatically trigger the test when playback of the test signal begins; it also serves as reference tone for any frequency shift calculations. Post-processing precisely synchronizes the stimulus and response waveforms, and then calculation of the measurement parameters proceeds as with any conventional headphone. In this case, analysis is performed using the Time Selective Response (TSR) algorithm which performs THD and fundamental frequency response analysis simultaneously in addition to producing an impulse response. The fundamentals are then post processed to derive the sensitivity of the left and right channels at 1 kHz.
Listen Awarded Patent for SC Amp Amplifier
Listen’s revolutionary audio test amplifier, SC Amp, has been awarded US Patent # 9,386,387. This patent covers Listen’s unique high accuracy single channel impedance measurement method, which used a unique feedback circuit to offer dual channel accuracy using just a single channel. This enables full electrical and audio tests to be carried out simultaneously and with high accuracy using just 2 channels.
Specifically designed for the audio test market, SC Amp also incorporates several other features unique to the needs of audio test and measurement, such as low distortion (THD <0.025%) and a low noise floor (>100dB). Fixed gain eliminates calibration errors as there is no gain knob to be accidentally knocked or tweaked when it is in use. It supports the application of a DC voltage offset to the AC signal for testing transducers under adverse conditions, and features overload/output protection to prevent damage in case of shorting or overload.
Many unnecessary features found in regular audio amplifiers have been eliminated to keep production line operation simple and error-proof. Although it is designed to integrate seamlessly with Listen’s SoundCheck audio test and measurement software, it will also work well with other brands of test system.
Listen president, Steve Temme commented, ‘We are thrilled that the innovative design of this product has been recognized with this patent, and we are confident that this method will be quickly recognized by the marketplace.’
New Manufacturing Team
Listen has expanded its manufacturing team with the addition of Evan Driscoll (left in picture) as Production Supervisor. Evan graduated from Wentworth Institute of Technology in 2015 with a B.S. In Electronics Engineering Technology, where he also received the President’s award. Evan is very familiar with manufacturing at Listen, having held several internships and temporary positions at Listen over the past 3 years.
Evan replaces Nick Alston (right in picture), who has been promoted to the position of Manufacturing Supervisor after 2 years in the Production Supervisor role. Together, Nick and Evan manage all of our manufacturing and hardware assembly, test, and QC, ensuring that products are build and delivered on-time to high manufacturing standards.
1-617-556-4104
LISTEN INC.
580 HARRISON AVE. SUITE 3W
BOSTON, MA 02118