Washington, June 13 : Being disturbed in the middle of the night by noisy neighbours' blasting out music could soon be a thing of the past, thanks to researchers in Spain, who have shown that metamaterials i.e. materials defined by their unusual man-made cellular structure, can be designed to produce an acoustic cloak that can make objects impervious to sound waves, literally diverting sound waves around an object.
The study is based on recent theoretical research, which has sought ways to produce materials that can hide objects from sound, sight and x-rays.
In order to realise the cloak physically, the research team calculated how metamaterials constructed with sonic crystals, solid cylinders in a periodic array that can scatter sound waves, could be used in a multilayered structure to divert sound completely around an object.
They performed multiple simulations to test their theory.
They investigated the optimum number of layers required to completely divert sound and how thin the materials could be made to maintain their use but also ensure that they are easy to implement.
They found that optimum cloaking requires approximately 200 layers of the metamaterial but that there is scope for much thinner materials to be used than technology can currently produce. So, put simply, watch this space.
"We hope that this proposal will motivate future experimental work demonstrating the materials' performance," said Jose Sanchez-Dehesa, one of the lead researchers.
One of the first uses of the material is likely to be warships, hoping to avoid sonar radars which pick up on the noise that ships emit, but if developments continue apace it could be used in concert halls to direct noise away from problem spots or even as a way to deal with noisy neighbours.
The study is published in the New Journal of Physics (NJP).