A light rigid structure (of aluminum or other material) which reflects sound to a focus at which a MICROPHONE is placed. This focussing effect is very strong with WAVELENGTHs less than the aperture of the reflector, making it particularly suitable for recording high frequency sounds such as birdsong.
Compare: DIRECTIVITY, DIFFRACTION, REFRACTION, SHOTGUN MICROPHONE.
Schematic diagram of a parabolic reflector. Incoming sound is directed to the microphone placed at the focus of the parabola-shaped reflector.
The property of the parabolic shape to reflect all sound symmetrically results in multiple REFLECTIONs known as 'slap echoes' when larger structures have this shape.
Sound Example: Multiple ECHOes produced under a parabolic bridge, Stanley Park, Vancouver, B.C. The source sound is a stick hitting a metal can.