Metamaterials are awesome in that they promise future ways to make real objects invisible to the eye and to block acoustic signals. This would be the prankster’s ultimate weapon. Imagine a suit that would allow you to sneak around unseen and unheard. I’d skulk around waiting for the skank down the street that is always bent over with her thong hanging out working in her flowerbeds gets to weeding and give her the wedgie of a lifetime.
There have been metamaterial acoustic cloaks before, but the caveat was that these cloaks could only hide things underwater. Researchers at Duke have discovered a new acoustic cloaking technique that will work in air. The metamaterials is a series of layers of perforated plastic.
The material is able to manipulate the sound waves in the air to make the majority of them seem like they passed through the solid object underneath and bounced back. The tests used a triangular wood block a couple inches high and more than a foot at the base. Despite early progress, the researchers say they are a long way from a full acoustic cloak.