Although the acoustic cloak has only been mathematically simulated, the engineers claim that devices based on their blueprint can make submarines invisible to sonar. "We have shown that acoustic cloaks theoretically do exist," said Duke University professor Steven Cummer. "Our recipe shows how to make an acoustic material that essentially opens up a hole in space--making whatever is inside that hole 'disappear'."
Further, the engineers claim that the technique proves that waves can be redirected around objects in different media, opening up the possibility of improving the acoustics in concert halls by cloaking structural beams from sound waves in air. It may even be possible to redirect seismic waves around buildings [making them earthquake resistant], or ocean waves around ships.
Besides fabricating an acoustic cloak based on the blueprint, the researchers also claim that the technique will make it possible to use metamaterials to bend and concentrate sound waves in new ways.