Abstract: A device for simultaneously modulating and amplifying low frequency sounds which comprises a tubular member having an axial bore extending a distance interiorly of the inlet end thereof and tapering to a reduced axial bore in said tubular member. A generally perpendicular passageway in said tubular member intersects said reduced axial bore, the top wall of which terminates adjacent to said intersection and the bottom wall of which extends past said intersection, said extended portion being deflected a finite angle relative to the normal axial flow. The tubular member is received by a sleeve, and a first baffle flared in the direction of the flow is angularly disposed relative to said sleeve to define a first passageway in said tubular member.

Abstract: A device for simultaneously modulating and amplifying low frequency sounds which comprises a tubular member having an axial bore extending a distance interiorly of the inlet end thereof and tapering to a reduced axial bore in said tubular member. A generally perpendicular passageway in said tubular member intersects said reduced axial bore, the top wall of which terminates adjacent to said intersection and the bottom wall of which extends past said intersection, said extended portion being deflected a finite angle relative to the normal axial flow. The tubular member is received by a sleeve, and a first baffle flared in the direction of the flow is angularly disposed relative to said sleeve to define a first passageway in said tubular member.