Research to determine the properties and characteristics of materials which can be used to attenuate/dampen the transmission and reflection of sound energy in military equipment, for example, ships, submarines, torpedoes, and other UUVs. Also includes support for applications requiring reduced signature materials. Also includes medical acoustic materials, flesh simulants, and materials for machinery isolation and blast protection, including active (smart) materials for control of vibration and noise. Research into processes which shape such materials and which lead to improved bonding to underlying structures. Includes relevant frequency selective or responsive materials.