Fooling the Ear
A Survey of Sound Auralization Methods

Matt Montag
AmbisonicsHRTFDigital Waveguide MeshWave Field Synthesis

Wave Field Synthesis and Holophonics

What Works

  • Sounds can be made to appear anywhere in 3D space
  • WFS works at any location inside the listening space; no longer relegated to "sweet spot"

What Doesn't Work

  • High cost - many loudspeakers required
  • Room acoustics must be suppressed
  • Truncation: wave field suffers inaccuracy at the edge of loudspeaker array
  • Aliasing: Loudspeaker spacing of 2cm required to eliminate spatial aliasing

What is it?

Wave field synthesis is a method of spatial audio reproduction that is capable of virtualizing complete acoustic environments. Sounds can be made to appear anywhere within or outside the listening area. The method doesn't rely on psychoacoustic exploits because it synthesizes a stable physical wave field.

WFS is based on the Huygens principle: a wavefront can be thought of as a superposition of numerous smaller wavefronts. Thus a wavefront for a virtual source can be approximated by overlapping wavefronts originating from actual sources at other positions. In practice, loudspeaker arrays are arranged in a line, plane, or a circle around the listener. Signals are emitted along the loudspeaker array at carefully measured delays to produce the desired composite wave front shape.
A wavefront constructed by parts
A speaker array for wave field synthesis

What is it used for?

Wave field synthesis is in use at a number of venues around the world. In particular, WFS technology is attractive to theaters. The Fraunhofer-spinoff IOSONO has wave field synthesis installations in Disney World, Orlando, Florida; Bavaria Filmstadt, Munich; Odysseum Science Adventure Park, Cologne; and at their offices in Los Angeles and Erfurt.

Essential Articles selected from 1160 articles

  1. Wave Field Synthesis and Holophony by Helmut Oellers
  2. The theory of wave field synthesis revisited. S. Spors, R. Rabenstein, and J. Ahrens. 124th AES Convention (2008)
  3. Acoustic control by wave field synthesis by Berkhout, AJ and De Vries, D. and Vogel, P. (1993)

Matt Montag 2010