You haven’t heard it all

Experimental cloak makes objects sound like they aren't there

A new cloak that hides objects from sound could really confuse a bat trying to echolocate in a cave. Sound waves striking a bump covered by the cloak bounce back as if they hit a flat wall instead.

A HOLEY SOUND An acoustic cloak made from holey strips of plastic metamaterial bends sound waves, making the object beneath acoustically undetectable.