There are several aspects of an automobile that the general public tends to take for granted. One such that most of us don’t give much thought is sound deadening. While noise isolation has always been important to keep the sound of an engine away from the cabin, it is equally vital for electric cars. The lack of noise from an engine makes it even more challenging for engineers to mask road and air noise in an electric car’s cabin.
Nissan is showing a new material at this year’s Consumer Electronics Show (CES) that the company says will help make car cabins quieter while also boosting energy efficiency. Although it is being shown at the trade show in Las Vegas now, Nissan started its research on acoustic meta-material technology more than a decade ago in 2008. At the time, meta-material was used in high-sensitivity antennas used for electromagnetic wave research. Nissan idea is to expand the scope of meta-material technology to include sound waves, leading to the successful invention of acoustic meta-material.
The new material is a combination of a lattice structure and plastic film, which together control air vibrations to limit the transmission of wide frequency band noise (500-1200 hertz), such as road and engine noise. Currently, automakers block this frequency band using heavy rubber boards. Nissan’s new acoustic meta-material weighs one-fourth as much as these while providing the same degree of sound isolation. Nissan claims the material’s simple structure lets them keep its cost competitive.