Noise vibration and harshness -- aka NVH -- has been the bane of car engineers for decades. It's made up of a combination of sounds and sensations from a vehicle's drivetrain as well as road noise and ambient noise (such as city sounds), and getting rid of it is tough.
In an electric car, that job is made even tougher because the vehicle's noise floor is much lower. A "noise floor" is the sum total of all the unwanted sounds that you have to overcome to measure a specific sound. An example would be that you're trying to have a conversation at a rock concert and your friend can't hear you because the combination of the music and all the other people talking has raised the noise floor of the room.
Because an electric car has almost no drivetrain noise, to mask things like road noise engineers have had to get creative in the ways that they try to dampen those vibrations coming through your vehicle's tires and into the cabin. Most use a combination of heavy rubber and fiber mats under the car's carpets, but
engineers say they've found something better.
Nissan announced its Acoustic Meta-Material on Tuesday at the 2020 CES show in Las Vegas. Where this "meta-material" differs from traditional sound-deadening materials is that it uses two layers of lightweight plastic with a honeycomblike lattice in between them. This structure uses air to essentially trap the relatively low-frequency vibrations (500Hz to 1,200Hz) that road noise is made of.
The Acoustic Meta-Material is especially interesting in the world of electric vehicles because of its weight-saving design. Nissan estimates that this material is around one-quarter of the weight of traditional materials, and less weight ultimately translates to better performance and increased range.
Nissan debuted the Acoustic Meta-Material on its Ariya concept this year at CES, but it has been working to develop the stuff since way back in 2008. Initially, the tech saw use as a component of highly sensitive antennae designed to measure electromagnetic waves.
We reached out to Nissan to get a better idea of when we might expect to see the meta-material find its way into the Nissan Leaf and other vehicles, but it didn't immediately respond to our request for comment.