Abstract: The device includes two movable members interconnected at their periphery by a flexible membrane defining therewith a tight enclosure of variable volume, a piston slidable in a cylinder integral with one of the two movable members and hydraulically actuated, to move the members apart from each other, a second cylinder separated in two compartments by an inner valve and controlling the actuation of the piston in response to the pressure of the water feeding said second cylinder, two apertures intermittently freed by the valve for releasing the piston and at least one aperture for the discharge of the water from the tight enclosure to the external water body when the piston release allows the two movable members to be urged toward each other, thereby producing an implosion which generates a strong sonic wave.

Abstract: A device for generating acoustic waves in a liquid, comprising two hollow enclosures communicating through a narrow passageway, a valve interposed in said passage way for controlling said communication, means for feeding a first one of said enclosures, in free communication with the ambient liquid, with pressurized fluid and suction means for reducing the pressure in the second enclosure to a level considerably lower than that prevailing in the first one.