Airplanes are loud, which is pretty much unavoidable. But engineer Yun Jing has invented something that can block that noise from reaching our ears.

The shell of an airplane’s cabin is made of a material that is lightweight, yet structurally dense. The problem with it is that it allows the sound waves generated by the jet engines and rotor blades to pass through it. The only way to change that, would be to find a way to insulate the cabin, which is exactly what Yun’s new metamaterial does.

Image: Yun Jing via QZ. Image 1.Image: Yun Jing via QZ

Metamaterials are synthetically-created materials that are made using regular materials, but have properties not found in nature. In this case, the metamaterial in question has a negative density. What this means is that when sound waves hit the surface of the material, rather than continuing in the direction, the material moves in the opposite direction, pushing the sound waves back towards where they originated. While adding only 6% of a weight increase to the structure of the cabin, this metamaterial could cut noise down by 20 decibels. Yun has yet to pitch this invention to airplane manufactures. He will first need to test his new metamaterial on a larger scale.