Ponca City, We Love You writes "The 'Cone of Silence,' once a staple of 1960's television shows, is now possible say scientists at Duke University who first demonstrated a working 'cloak of invisibility' that works at microwave frequencies in 2006. Such a cloak designed for audio frequencies might hide submarines in the ocean from detection by sonar or improve the acoustics of a concert hall by effectively flattening a structural beam. Although the theory used to design such acoustic devices so far isn't as general as the one used to devise the microwave cloak, the finding nonetheless paves the way for other acoustic devices. 'We've now shown that both 2-D and 3-D acoustic cloaks theoretically do exist,' says Researcher Steven Cummer. 'It opens up the door to make the physical shape of an object different from its acoustic shape.'"