Sound Field Control

Good sound instead of noise

Sound field control describes the targeted influencing of sound fields using intelligent signal processing algorithms that control (vibro)acoustic actuators. The aim is to influence the sound in such a way that the desired sound field or listening experience is created at the listening location. Our research focuses on adaptive signal processing using machine learning methods, the use of sensor and actuator arrays and control technology. In terms of application, we focus on the areas of entertainment, operational safety in the mobility and industrial sectors and active noise protection for environments and individuals.

News and upcoming events

 

Conference I March 18 – 21, 2024 I Hannover

DAGA 2024

This year, Fraunhofer IDMT will once again be presenting current research results in various contributions at the DAGA.

 

Research project

VibroClean

Acoustic solar module cleaning

Desired and undesired sounds and sound fields

Noise and unwanted sounds have been proven to impair human health, well-being, and performance. Disturbing noises, for example, when talking on the phone in the car or during mobile work, impair the ability to concentrate. Undisturbed sleep and relaxing music, on the other hand, provide a good basis for high performance. A distinction can therefore be made between undesired sound fields, e.g., noise, and desired sound fields, e.g., emergency announcements or music at concert venues. Often, both undesired and desired sound fields occur simultaneously.

For these reasons, researchers are working on various approaches to detect (with sensors), analyze and influence sound fields. The physical acoustic phenomena are usually considered taking into account human auditory perception.

Active enhancement and targeted generation of sound fields

The creation and control of sound fields requires a comprehensive understanding of their generation, propagation, and detection. Noise sound fields, such as those that occur in ventilation systems, can be compensated for by using active absorbers. Currently, there is a lack of solutions that are easy to put into operation, featuring self-monitoring and automatic recalibration.

In cars, not only disturbing vehicle, and traffic noises, but also noises from the neighboring seat (speech, music, etc.) should be suppressed. For this purpose, the various sound fields and their propagation in the car chassis and in the air must be detected by sensors, evaluated, and used as a starting point for controlling existing anti-sound measures. Special sound fields, such as alarm signals, must be handled separately.

The technical solution should initialize itself as independently as possible. Operating parameters should automatically adapt to changing system characteristics (aging, number of passengers, loading, etc.) and environmental conditions. To achieve this, algorithms must be developed that are computationally efficient, energy efficient, and robust.

How to proceed

Depending on the application, different methods are used to control sound fields:

  • Active Noise Control (ANC)
  • near-field sound reinforcement
  • loudspeaker array technology for: Beamforming, Wave Field Synthesis, planar speakers
  • Beamforming
  • Wave Field Synthesis
  • active absorbers
  • metamaterials

 

Research project

Metavib

Metamaterials for controlling vibroacoustics by means of the resonator effect

 

Research project

VibroClean

Acoustic solar module cleaning

 

Research project

Clean Air Acoustics

Acoustically optimized compact ventilation systems and air purification devices

Products

 

SpatialSound Wave for Professional Audio and Entertainment

Object-based audio production and reproduction for an authentic sound experience

 

SpatialSound Wave for Automotive Audio

The audio platform for the car of the future: holistic sound management for creating immersive and interactive audio content

 

Personal Sound Zones

Individual listening comfort

 

Planar Speakers

Great sound quality and space-saving, flexible design

Services

  • sensory detection of airborne and structure-borne sound fields (sound pressure, sound velocity, sound intensity) 
  • sound field decomposition into single sound sources
  • transfer path analysis for sound sources
  • generation of static/variable sound fields by means of loudspeaker/speaker array/flat loudspeaker
  • generation of focussed sound fields/spatially limited sound fields
  • generation of anti-sound fields for sound reduction
  • sound optimization of loudspeaker reproduction systems

 

Equipment

 

Equipment

Equipped with state-of-the-art special rooms and laboratories we enable a a wide variety of acoustic measurements and investigations. Please feel free to contact us!

Fischer, Georg; Zykhar, Albert; Küller, Jan; Troll, Agostino (Fraunhofer IBP)
Designing Active Acoustic Metamaterials
Tagungsband, Fortschritte der Akustik - DAGA 2023, Herausgeberin: Deutsche Gesellschaft für Akustik e.V. (DEGA), Berlin, 2023
Wissenschaftliche Edition: Otto von Estorff, Stephan Lippert, ISBN: 978-3-939296-21-8

Sladeczek, Christoph; Seideneck, Mario; Lorenz, Wolfgang; Pursche, Katrin; Schneider, Benjamin (DSP Concepts)
Object-Based Audio as Platform Technology in Vehicles
Proceedings, AES 2022 International Automotive Audio Conference, June 8 – 10, 2022, Detroit, USA

Beer, Daniel; Fritzsche, Paul; Bernhard, Fiedler; Rohlfing, Jens; Bay, Karlheinz; Troge, Jan; Millitzer, Jonathan; Tamm, Christoph
Luftreinigungsgeräte - akustische Anforderungen und Optimierungsmöglichkeiten
Tagungsband, Fortschritte der Akustik - DAGA 2022, Herausgeberin: Deutsche Gesellschaft für Akustik e.V. (DEGA), Berlin, 2022
Wissenschaftliche Edition: Philip Leistner, ISBN: 978-3-939296-20-1

Troll, Agostino; Rohlfing, Jens; Küller Jan; Fischer Georg; Beer, Daniel; Lühring, Andreas
Investigations on working principles and design methods for metamaterial silencers
Tagungsband, Fortschritte der Akustik - DAGA 2021, Herausgeberin: Deutsche Gesellschaft für Akustik e.V. (DEGA), Berlin, 2021, ISBN: 978-3-939296-18-8