Abstract: An acoustic/shock wave attenuating assembly comprised of porous screens forms an enclosure filled with a suitable pressure wave attenuating medium or material having fluid characteristics. This basic configuration can be suspended or held in place by a rigid structure. When the pressure attenuating medium is a liquid, the attenuating assembly is provided with a lining for containment. Multiple attenuating assemblies can be employed, with adjacent attenuating assemblies separated by a small gap. The pressure attenuating medium may be a liquid, a gas emulsion, an aqueous foam, or a gel (with or without entrained gas). Alternatively, solid particulates having bulk mechanical properties of a fluid may be employed as the pressure wave attenuating medium and may have an adhesive or the like resisting relative movement between particulates to simulate viscous effects.