Sound & Hearing

Sound Zone Plate

SOUND ZONE PLATE is a carefully designed assemblage of rings. The rings are positioned so that the structure focuses sound waves. A speaker on one side of the plate emits either a sound of well-defined frequency or a sound with a combination of well-defined frequencies. Each frequency is brought to a focus somewhere on the other side of the plate. Different frequencies are focussed in different locations.
The Zone Plate does with sound what a hologram does with light. A complex hologram is made up of a huge number of photographic zone plates which focus light to make up the holographic image.