Noise, vibration and harshness, or NVH, has become a hot topic for many car buyers – even on entry level economy cars. In an electric car, road noise becomes even more apparent due to the lack of an internal combustion engine.
In a space where innovation is rarely seen, Nissan has developed a new sound insulation material, known as acoustic meta-material, to be demonstrated in the Consumer Electronics Show (CES) this week.
The acoustic meta-material is made up of a lattice structure, paired with a thin plastic film. The structure works particularly well against wide frequency band noise (500 – 1200 Hz), such as road and engine noise.
The simple structure and material make-up means the acoustic meta-material is minimal on weight, especially when compared to the heavy rubber boards commonly used to thwart the wide frequency band noise.
Nissan claims that the acoustic meta-material weighs 75% less than these materials, while providing the same degree of sound isolation. The lower weight results in a lower overall environment impact, due to increased driving efficiency.
The Japanese firm also says that material costs could be lower in a mass-production scenario, due to the simple lattice structure. This could mean that more lower-end cars can receive sound isolation treatments, where it is currently limited by cost or weight.
Nissan started research on meta-material technology around 2008, where it was initially developed for use in electromagnetic wave research. Nissan engineers worked to expand the applicability of the material to sound waves, which eventually led to the invention of the acoustic meta-material.