Acoustic Visualization

In 2004 I worked on a project that needed to visualize some acoustic data. So I developed a Perl program that used Image::Magick to produce the frames of the animated image shown here. The purpose of this diagram is to show the effect of single source of sound and a single device called the emitter. The function of the emitter is to exactly cancel out the sound from the source at a particular point.

For simplicity, the point where the sound from the source is to be cancelled has been placed at the origin of the coordinate system. The X and Y axes have been marked with the red horizontal and vertical lines respectively.

The source is located 40 feet to the left of the origin. The sound waves emanating from it are the dominate feature in the diagram. I have drawn a red circle with a 40 foot radius centered at the source. This circle appears as the large arc in the diagram.

The emitter is located 5 feet from the origin, up and to the left. You can see that its sound waves are less influential than the ones from the source. The emitter has a smaller red circle drawn around it with a radius of 5 feet.

The sound waves in the diagram are represented as shades of gray. The sound is scaled so the peaks of the waves are white and the valleys are black. If you watch closely at the points where the two red circles intersect, you will see that the sound waves are always black there. This indicates that the two sound waves have cancelled each other out.

For more technical details click here.

For an HTML5 Canvas version click here.