EVs drive NVH material innovations

Skateboard platforms, high-frequency motor noise push lower dB thresholds and new countermeasure solutions.

The definition of a ‘quiet’ vehicle, as determined by the occupants' ears, is changing radically, as electric motors replace the internal-combustion engine. And electric vehicles are changing the technologies used to reduce, and eliminate, NVH - noise, vibration and harshness. Removing the piston engine, with its exhaust, intake and valvetrain/injector noises, unmasks a plethora of cabin sounds that occupants never heard before.

“ICEs generate at least 20 dB more noise at the cabin level,” noted Vahid Mortazavian, Ph.D, global CAE leader at Ascend Performance Materials, in a presentation at the 2022 SPE Automotive conference. Tire and road noise become more prevalent in an EV. Even the heater fan is louder without engine noise to mask it. But EVs generate their own noises, including high-frequency buzz from the electric motor. These are among the new challenges facing development engineers and NVH specialists.