New Automotive Test Sequence

We have a new automotive test sequence to measure Transient Distortion (also known as buzz, squeak, and rattle, Rub & Buzz, or impulsive distortion), Frequency Response, and Max SPL to the suggested measurement methods set out in the AES Technical Committee on Automotive Audio’s recently published white paper on in-car acoustic measurements. The three measurements are incorporated into one overall test sequence, making it fast and simple to run the entire suite of tests. This sequence facilitates evaluation of the committee’s proposals, and also serves as a basis for any similar in-house measurements. The white paper, which may be obtained from the TC-AA, outlines both measurement methods and physical configuration such as microphone and seat positioning in an effort to simplify comparison between vehicles.


In-Car Audio Measurements

This sequence tests the impulsive distortion, frequency response, and maximum sound pressure level of a vehicle infotainment system to the methods outlined in the Audio Engineering Society Technical Committee on Automotive Audio (TC-AA) in-vehicle measurements white paper. This white paper aims to define repeatable and defined car audio system measurements and in addition to the measurement methods, contains information on standardized test configuration, for example microphone and seat positioning. Please contact the TC-AA for more information on this project. This test sequence may, of course, be used with your own in-house physical configuration if adherence to the TC-AA guidelines is not essential.

This sequence includes one master sequence, three subsequences, plus a level check subsequence for calibration. The three individual subsequence tests have also been included in a separate folder so they may be run standalone. The standalone sequences each have their own Bluetooth connect and disconnect steps.


AES 2022, New York, October 19-20, 2022

At AES New York, Steve Temme will participate in presentations and discussions on ‘In-car audio measurement’ (with Jayant Datta) and ‘Moving beyond traditional measurements’ (with Jayant Datta and Jonathan Gerbet). Exact schedule and timings are yet to be announced.

Measuring Loudspeaker Maximum Linear Sound Levels Using Noise to the AES75-2022 Standard

The AES75-2022 standard details a procedure for measuring maximum linear sound levels of a loudspeaker system or driver using a test signal called M-Noise. This is a complex procedure with many repetitive steps, which makes it time consuming to implement manually. This sequence automates the entire process, accelerating test time, minimizing operator intervention, and ensuring accurate and objective test results.


Enhanced Perceptual Rub & Buzz Measurement for Testing Automotive Loudspeakers

Loudspeaker Rub & Buzz faults are a problem for automotive manufacturers as they sound harsh and immediately give the perception of poor quality. There are two places such faults can occur – during speaker manufacturing and installation of the speaker in the car. A buzzing loudspeaker in a car is disappointing to a customer and is costly to replace. It is also challenging for a service center to determine exactly where the buzzing is coming from and whether it is caused by a faulty loudspeaker or bad installation. Perceptual distortion measurements are often considered the holy grail of end-of-line testing because rejecting speakers with only audible faults increases yield. Although such measurements have been around since 2011, production line adoption has been slow because until now, sensitivity to background noise has made limit-setting challenging. In this paper, a new algorithm is introduced that uses advanced technology to reduce the impact of background noise on the measurement and offer more repeatable results. This facilitates limit setting on the production line and makes it a truly viable production line metric for increasing yield. This same metric may also be used for end-of-line automotive quality control tests. Results from various algorithms will be shown, and their correlation to subjective and other non-perceptual distortion metrics explained.

Authors: Steve Temme, Listen, Inc.
Presented at 2022 AES Automotive Conference, Dearborn, MI

Full Paper

AES 2022 International Automotive Audio Conference

We’ll be attending and exhibiting at the AES International Automotive Conference in Detroit, June 8-10. Stop by and visit our booth to learn more about the latest version of SoundCheck, including a host of new features designed for multichannel and communications testing, as well as the new enhanced perceptual Rub & Buzz algorithm. Listen founder and president, Steve Temme, will be presenting a paper on June 8th (paper session 1, 10.30 am) detailing this new algorithm, and will also participate in a panel discussion on Max SPL measurement in cars at 4.00pm on June 9th.


AES Convention– New York – October 16-19, 2019

Although Listen won’t be exhibiting, president Steve Temme will be at the event and will be participating in two product development sessions detailed below.


Product Development: PD09 – Does Automotive Audio Need a Systems Approach?

Thursday, October 17, 1:30 pm — 3:00 pm (1E09)

Chair: Roger Shively, JJR Acoustics, LLC

Panelists: John Busenitz, Bose Corporation, Pietro Massini, Ask Industries S.p.A, Greg Sikora, Harman International, Steve Temme, Listen, Inc.

Some component specifications do not translate to good system performance. A good example is resonance frequency. This often does not correspond well to performance characteristics in the automotive environment. Some potential improvements would be low-frequency SPL, or a parameter combination such as Fs/Qts or EBP (Fs/Qes). The system performance goals should drive the transducer component specification. Hence, this workshop will host leading industry experts in automotive audio and test/measurement solutions to discuss pros and cons of component vs. system specifications.


Product Development: PD10 – Diagnostics for Production Vehicle Audio Systems

Thursday, October 17, 3:15 pm — 4:30 pm (1E09)

Presenters: Jonathan Gerbet, Klippel GmbH, Steven Hutt, Equity Sound Investments, Steve Temme, Listen, Inc.

Audio systems in production vehicles are known to exhibit vehicle to vehicle performance variance [1]. The root causes of variance can include loudspeaker driver manufacturing tolerance, mounting issues such as missing or misaligned gaskets, or wrong loudspeaker drivers mounted in the system. A diagnostics method to compare actual production vehicle audio systems is defined along with a method for correction and calibration of production vehicle audio systems. The diagnostics procedure may be implemented at production end-of-line, at vehicle distribution center or at a dealer service center in the field after delivery to a customer.

Full AES Schedule

AES International Conference on Automotive Audio – Munich – September 11-13, 2019

Listen is a gold sponsor and exhibitor at the AES International Conference on Automotive Audio in Munich, Germany on September 11-13.

Listen founder and president, Steve Temme, will be presenting a tutorial on ‘Testing Voice-Controlled and Smartphone Integrated Infotainment Systems’ at 2pm on Sept 11th. In this tutorial he will discuss the challenges of implementing audio tests in cars when the signal path is often via a smartphone and/or the car’s own voice-controlled system, and demonstrate how modern test systems can use techniques such as frequency shift and resampling to enable accurate measurement of car audio characteristics ranging from simple frequency and distortion measurements to voice control and communications in the presence of background noise.

On display at the the booth will be various options for testing automotive audio including the SoundCheck test system, Listen’s own audio test hardware, and 3rd party hardware such as 6 microphone arrays and head and torso simulators. On the booth, Listen will also be demonstrating how SoundCheck fully integrates with, and controls, the Mentor A2B interface to enabled rapid automated testing of systems and components that use the A2B bus.


AES, Los Angeles, CA, Sept 29- Oct 1, 2016

AES LogoWe will be exhibiting at the 141st AES which will be held at the Los Angeles Convention Center, LA, CA on Sept 29-Oct 1, 2016.

At our booth (#717) we will be demonstrating SoundCheck 15, our latest release, as well as our lineup of audio test hardware. We will be demonstrating a comprehensive Bluetooth headphone test using SoundCheck with the BTC4148 Bluetooth interface and the Brüel and Kjær Head and Torso Simulator.

Steve Temme, along with Patrick Dennis of Nissan, will be presenting a technical paper entitled “In-Vehicle Audio System Distortion Audibility versus Level and Its Impact on Perceived Sound Quality” This paper will take place Friday Sept 30th at 3.15pm in the “P15 Perception” paper session. In this paper, the authors consider the level of distortion as in-vehicle audio system output level increases, and evaluate the level at which distortion audible is audible. Both subjective and objective measurements of sound quality are made, and the correlation between perceived sound quality and objective distortion measurements is discussed.

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AES, New York, NY, Oct 29-Nov 1 2015

AES LogoWe will be exhibiting at the 139th AES which will be held at the Javits Center, New York, NY on Oct 29-Nov 1, 2015.

At our booth (#242) we will be demonstrating the latest release of the SoundCheck software, version 14,  and the new SoundCheck 14.1 for Mac, as well as showcasing our entire audio test hardware lineup including the new AudioConnect audio interface and BTC-4148 bluetooth interface. We will be demonstrating how you can test virtually any type of audio or audio electronic device with the SoundCheck test system, and showing off some of the latest features of our software.

Steve Temme will also be co-presenting a paper entitled ‘Headphone Response: Target Equalization Trade-offs and Limitations’ with Christopher Struck of CJS Labs. This paper is first up in the P4-1 session (Transducers, Part 1) at 2.30pm on October 29th. In this paper, the effects of headphone response and equalization are examined with respect to the influence on perceived sound quality. Free field, diffuse field, and hybrid real sound field targets are shown and objective response data for a number of commercially available headphones are studied and compared. Irregular responses are examined to determine the source of response anomalies, whether these can successfully be equalized and what the limitations are. The goal is to develop a robust process for evaluating and appropriately equalizing headphone responses to a psychoacoustically valid target and to understand the constraints.

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