Apparatus for the retroreflection of sound
AssigneeLockheed Corporation
InventorLeslie S. Wirt
Life of this patent
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Abstract
A noise control device which relies upon retroreflection for sound attenuation. The device comprises an array of corner reflectors recessed into a surface and forming a sound retroreflecting panel. This cavitated surface provides the desired retroreflection of impinging sound waves so as to preclude undesirable onward propagation. The invention is particularly suitable for noise control applications in the presence of severe environmental conditions, and may also be used in combination with sound absorbing materials.
Claims12
An apparatus for the controlled retroreflection of sound comprising:
- a plurality of acoustical retroreflectors each having the form of a substantially orthogonal pyramidal cavity, the exposed surfaces of which have a dimension of the order of or greater than one-quarter of the wavelength of the sound to be controlled;
- and
- means for mounting said retroreflectors in a contiguous array for reception of an incident acoustical wavefront.
An acoustical treatment for a passageway or duct comprising
- a plurality of acoustical retroreflectors each having the form of a substantially orthogonal pyramidal cavity and disposed in a contiguous surface array;
- and
- means for mounting said array on at least one interior wall of said passageway or duct.
Dependencies are inferred from the claim text.