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US 4,228,867 AGranted
Noise barrier
AssigneeLockheed Corporation
InventorLeslie S. Wirt
Life of this patent
Estimating the term…
Abstract
A noise barrier wall having a transition area in the region of at least one unbounded edge and which employs controlled diffraction of sound to enhance the sound reducing properties thereacross. The transition area of the noise barrier is provided with either a row of absorptive shaped splitter panels, or a row of pickets, or other means of controlled transparency which provide acoustical shadowing equal to or greater than that of a solid wall for the frequency regions of interest.
Claims8
An acoustical barrier for interposition between a noise and a noise receiver located within the acoustical shadow zone of the barrier, comprising:
- a barrier member having an acoustically opaque base portion and having contiguous therewith an upwardly extending transition portion comprising a plurality of identical spaced apart elements contiguous with said base portion defining a plurality of flow ducts therebetween and each of such ducts having an effective path length which continuously decreases in said upwardly extending direction whereby the sound transmissibility between said elements follows a gradient and the sound transmitted between said elements tends to apply a phase opposition to the sound arriving at the noise receiver by refraction in the acoustical barrier through a region outside said shadow zone and thereby effectively redirect such refracted sound away from said noise receiver.
Dependencies are inferred from the claim text.