Avoid annoying noise with sound insulation

Scientists in Spain have proven that metamaterials - materials with unusual artificial structures - can be designed to make a sound barrier that causes sound waves not to pass through objects or In other words, it diverts the sound waves around the object.

This work is based on another recent theoretical study that seeks to create materials that can hide objects in sound, vision and X-rays. Daniel Torrent and José Sánchez-Dehesa of Wave Phenomena, Faculty of Engineering A study at the University of Valencia, published last year by the researchers from Duke University in North Carolina, is the starting point for a practical approach. Their higher.

To understand the material form of the soundproofing, the Spanish team calculated how the metamaterial made up of crystalline sound, solid cylinders in a circular series that can break sound waves, have The ability to be used in a multi-layer structure to completely change the direction of sound around an object.

Soundproofing. (Photo: Academy of Physics)

The researchers performed many simulations to test their theory. They check the number of layers that are suitable to completely change the sound direction and the material's slimness can be achieved in order to maintain the functionality with ease of implementation.

The result is very encouraging, the optimal sound insulation requires 200 layers of metamaterials, but it is still possible to use materials much thinner than today's technology. So, in simple terms, let's wait and see what happens.

José Sánchez-Dehesa, one of the principal investigators, wrote: 'We hope this proposal will promote future laboratory research demonstrating the viability of the material.'

One of the first applications of this material was probably warships, which prevented them from detecting the sound of the ship. But if the material grows rapidly on a large scale, it can be applied in the theaters to direct noise away from problem spots or even be used as a way to deal with noisy neighbors. .

Reference: Two-dimensional sound insulation: a practical method. June 13, 2008 Physics Journal (NJP)