Modeling and Measurement
Speakers and Microphones: Simulation and Testing

August 11, 2021
9:00 AM Pacific (12:00 PM Eastern)

Overview

The Audio Product Education Institute (APEI) presents a webinar on modeling and measurement, focusing on exploring multiphysics simulation of the spatial response of speakers and microphones, and the different echo metrics that are used in voice quality testing. Speakers from COMSOL, the multiphysics and acoustics simulation software company, and HEAD acoustics, one of the world’s leading companies for integrated acoustic solutions as well as sound and vibration analysis, will share their experiences in two separate sessions, followed by time for questions.
 
Providing another learning opportunity on the use of simulation and measurement solutions for audio product design, this webinar will detail the ability to predict and understand the spatial response of microphones as well as the spatial response of loudspeakers, an increasingly important function when developing modern consumer audio products. Feedback and echo cancellation plays an important role in these products, and the ability to predict and reduce feedback in the transmission path from source to receiver is very important. In this session we will look at ways to model both the source and the receiver responses, using techniques such as reciprocity, as well as the full feedback path. Early assessment is important as DSP algorithms can then be developed and fine-tuned before any physical prototypes are made. 
 
In the presentation by the HEAD acoustics, attendees will learn about the different echo metrics that are used in Voice Quality testing as well as double talk analysis techniques. Topics to be covered include the definition of echo, how does delay affect echo, different metrics used to characterize echo, what is double talk, and why it’s important metric. Finally, the presentation will review the different analysis techniques used to quantify double talk.
 
This event will be presented by COMSOL. Following the opening remarks and introduction, the event will feature two presentations from Mads Herring Jensen (COMSOL) and Jacob Soendergaard (HEAD acoustics). In general, attendees will expand their understanding of the use of simulation in audio product design, addressing virtual prototyping, testing, measurement, multiphysics simulation, and optimization.
 
Session 1: Mads Herring Jensen (COMSOL)
Simulation of the Spatial Response of Speakers and Microphones
The ability to predict and understand the spatial response of microphones as well as the spatial response of loudspeakers is important when developing modern consumer audio products. Feedback and echo cancellation plays an important role in these products. To predict and reduce feedback the transmission path from source to receiver is also important. In this seminar we will look at ways to model both the source and the receiver responses, using techniques such as
reciprocity, as well as the full feedback path. Early assessment is important as DSP algorithms can then be developed and fine-tuned before any physical prototypes are made.
 
Session 2: Jacob Soendergaard (HEAD acoustics)
Echo and Double Talk Testing: Basic to Advanced
Echo has been identified since the beginning of voice communications as one of the most annoying impairments that users can encounter. Nothing can end a phone call faster than persistent echo! Since echo is such a nuisance there are many ways to characterize echo and understand how an echo canceller is performing. Additionally, if we consider real-world conversations where double-talk easily occurs, the task of ensuring communication flows seamlessly between both/multiple parties becomes much more difficult. Not addressing processing issues such as delay, device response time, voice activity detection (VAD), echo cancellation and many others can make real-time two-way communication almost impossible.
 
Jacob Soendergaard

Telecom Account Manager, HEAD acoustics
Michigan, USA

Jacob Soendergaard is an Audio and Acoustics aficionado privileged to be employed in the industry. Receiving a B.Eng from Imperial College and MSc from University of Sussex, Jacob spent the following 7 years working for GRAS Sound & Vibration in a variety of technical and commercial roles focusing primarily on the Consumer Audio and Hearing Health industries. Since Jan 2016, Jacob transitioned to a Senior Account Manager role with HEAD acoustics Inc., working with consumer and business customers on the goal of improving audio, voice and conversational quality in their products. His industry contacts include various tech giants as well as a number of global players in the field of acoustics and communication quality. 
 
HEAD acoustics GmbH is one of the world’s leading companies for integrated acoustic solutions as well as sound and vibration analysis. In the telecom sector, the company enjoys global recognition due to the expertise and pioneering role in the development of hardware and software for the measurement, analysis and optimization of voice and audio quality as well as customer-specific solutions and services. HEAD acoustics’ range of services covers sound engineering for technical products, investigation of environmental noise, speech quality engineering as well as consulting, training and support. The medium-sized company from Herzogenrath near Aachen has subsidiaries in China, France, Italy, Japan, South Korea, the UK and the USA as well as numerous sales partners worldwide.
Mads Herring Jensen

Technology Manager, Acoustics, COMSOL
Copenhagen, Denmark

Mads Herring Jensen joined COMSOL in 2011 and is the technology manager for the acoustics products. Mads has a PhD in computational fluid dynamics from the Technical University of Denmark. Before joining COMSOL, he worked in the hearing aid industry for five years as an acoustic finite element expert.