Sound Field Analysis and Measurement Techniques

Presentation by Efren Fernandez-Grande

Sound field analysis and measurements

General description

Advanced experimental methods are useful to analyse complex sound fields, examine how acoustic sources radiate sound, and characterize the acoustic properties of materials. These methods include sound intensity mapping, microphone array measurements, and other measurement principles, all of which provide valuable information complementary to conventional single point pressure measurements.

Sound field analysis methods often rely on measuring with an array of microphones, so that the temporal and the spatial properties of a sound field can be characterized. By means of spatial signal processing, it is possible to visualize the acoustic waves, localize sound sources, or reconstruct the sound field using acoustic holography, which makes it possible to predict the acoustic field in a different position than measured. In addition, different array configurations can be used, such as conventional planar arrays, arrays with random sampling positions, or spherical arrays, which are useful in rooms and enclosures.

Our research deals with methods such as:

  • Near-field acoustic holography
  • Beamforming, deconvolution and high-resolution imaging
  • Sound intensity mapping
  • Etc.

These techniques are useful to analyse the sound field radiated from acoustic sources, as they provide an effective and rapid insight into the source and the mechanisms that generate the sound field (this is valuable to address and solve noise problems, but also to design sound sources that radiate sound in a desired way, for example loudspeakers or musical instruments). These measurement methods are also useful for environmental noise measurements, and to analyse sound fields inside rooms and other closed environments, as they provide valuable information on the directional properties of the sound field and the properties of the reflecting surfaces.

Research topics at ACT

  • Near-field acoustic holography
  • Spherical array processing
  • Beamforming and source localization methods
  • Compressive sensing in acoustics
  • Sound radiation, supersonic intensity and spatial filtering
  • In-situ acoustic impedance estimation
  • Diffusivity characterization
  • Particle velocity and sound intensity measurements
  • High-resolution imaging and aeroacoustic imaging methods
  • Sound field separation methods
  • Inverse problems in acoustics
  • New acoustic transduction principles and novel transducers
  • Sound field reproduction
  • Etc.

 

Contact

Efren Fernandez Grande
Assistant Professor
DTU Electrical Engineering
+45 45 25 39 40
http://www.act.elektro.dtu.dk/Research/Research_fields/Sound-field-analysis-and-measurements
20 FEBRUARY 2017