Sound masking system for open plan office

Claim 1

An acoustic masking system for obtaining conversational privacy in an open plan office space having a floor and an acoustic ceiling wiith a plenum space above said ceiling, said plenum space having its own sound reflecting ceiling, said office acoustic ceiling having characteristics incuding sound absorption, reflection and transmission therethrough, said system having a generator for providing electric currents which are reproduced by a loud speaker as predetermined random noise, and speaker means connected to be energized by said generator output, said speaker means consisting of at least one cluster of two speakers for mounting in said plenum region, a cluster having a trigonal prism-shaped speaker cabinet having three flat prism panels shaped and assembled to form a triangular prism-shaped hollow cabinet with two triangular end plates, a loud speaker mounted in two of said prism side panels, each panel functioning as a baffle board for propagating sound outwardly by its speaker, said cabinet being adapted to be installed in the plenum region to orient said prism horizontally, said speakers being symmetrically disposed in their panels when said cluster is installed and being equally inclined from a horizontal plane in such installed position, said speakers being similar and adapted to be simlarly energized so that sound waves from said speakers can travel along air paths to solid surfaces for reflection therefrom, absorption thereby, and transmission therethrough to provide masking background noise in the open plan office.