WFS Visualizer

WFS Visualizer by Matt Montag (github).

Reproduced from his web page (all credits belong to Matt Montag).

This is a Processing sketch/Java applet that simulates wave field synthesis. A virtual source follows the position of the mouse cursor. It’s useful for visualizing the behavior and limitations of WFS.

Latest Version: March 29, 2011

Key Commands:

p Toggle primary wave
1/2 Increase/decrease resolution
q/w Adjust tapering profile (cosn)
Left arrow/Right arrow Decrease/increase number of loudspeakers
Up arrow/Down arrow Increase/decrease array spacing
[/] Decrease/increase signal wavelength
s Change signal waveform (sine, noise, and saw)

Applet not supported.

Physical acoustics overview

In order to study the spatial properties of audio we need to know what is sound and how it behaves in space: how it propagates, what energy it does carry, how it does interact with other sound sources.

The first lecture of the course is therefore a 2h introduction to acoustics, and therefore it is a summary of what you already know from previous acoustics courses:

The topics we will treat will be:

  1. Waves on the air
    • The wave equation
    • Plane waves
    • Spherical waves
    • Energy and intensity
    • Decibel scale
  2. Features of the acoustic field
    • Frequencies and energies
    • Coherence and incoherence. Interference
    • Reflexion and reverberation
  3. Waves in a room
    • Room modes and geometric acoustics
    • The impulse response: direct sound, early reflections, reverberation
    • Reverberation time
    • Diffuse sound field
  4. Green function method
    • Wave equation in presence of sources
    • Diffraction and the Huygens principle
    • Green function in the free field

As references, any good acoustics book will do, like Kinsler‘s book, or even basic physics textbooks such as the one by Tipler. You can also check your lecture notes for previous courses.

Longitudinal wave traveling through a material medium. Extracted from Dan Roussell’s Acoustics and Vibration Animations

Also you can get good acoustics simulations in Dan Roussell’s Acoustics and Vibrations Animations web page. See in particular the following animations:

New course 2015-16: Introduction to Spatial and 3D audio

Welcome new students to the blog of the subject “3D audio”. We hope you will find this resource useful.

By spatial audio we refer to the investigation of techniques for sound

  • recording and encoding
  • transmission
  • manipulation (postproduction)
  • exhibition

taking into account the spatial properties and the spatial nature of sound. Spatial audio would be a term of widespread academic usage.

By 3D audio we mostly refer to the spatial audio techniques which  go beyond traditional stereo or 5.1/7.1 surround and which normally include height. It is rather a commercial term.