World's First 3D Acoustic Cloaking Device Hides Objects from Sound

Duke University engineers have demonstrated the world's first three-dimensional acoustic cloak. Their device reroutes sound waves to create the impression that both the cloak and anything beneath it are not there. It works in all three dimensions, no matter which direction the sound is coming from or where the observer is located, and holds potential for applications like sonar avoidance. The geometry of simple plastic sheets and placement of holes interacts with sound waves to make the device appear as if it isn't there. This video demonstrates the difference in how sound waves act with and without the acoustic cloak in their path. The red and blue lines represent the high and low points of the sound waves. As they return to the top of the frame, the profile of the sound waves on the left with nothing in their way closely matches the profile on the right after interacting with the acoustic cloak. In contrast, the center trial shows the deformation of sound waves that occurs with an uncloaked sphere in their path.