Soundproofing Electric Vehicles & Batteries

How Soundproofing EVs & Batteries Works

Electric vehicles (EVs) and their battery systems generate unique noise profiles compared to traditional vehicles, primarily due to electric motors, inverters, and cooling systems. Unlike internal combustion engines, EVs produce high-frequency noise (200–4000 Hz) from inverters and motor whine, which can reach sound pressure levels (SPL) of 50–70 dB(A) in the cabin, affecting passenger comfort. Battery packs also contribute structure-borne noise through vibrations from cooling fans and thermal management systems, typically in the 20–200 Hz range, which resonate with the vehicle’s chassis.

Airborne noise in EVs is driven by electromagnetic whine and fan operation. For example, an inverter switching at 10 kHz can produce harmonics audible in the 1000–2000 Hz range, creating a high-pitched hum. Battery cooling systems, essential for thermal regulation, add fan noise in the 500–3000 Hz range, further elevating cabin SPL. These noises, while quieter than combustion engines, are more noticeable in EVs due to the absence of engine rumble, making soundproofing critical for a premium driving experience.

Sontech’s Acustimet® addresses airborne noise with microperforated panels, achieving an absorption coefficient (α > 0.9) in the 500–4000 Hz range. Based on Helmholtz resonance, Acustimet® traps and dissipates sound waves, reducing inverter and fan noise by up to 10 dB. Its lightweight construction (under 2 kg/m²) minimizes impact on EV range, making it ideal for cabin linings and battery enclosures.

Structure-borne noise, originating from battery vibrations or motor mounts, is mitigated by VIBRALON 25 SB. This viscoelastic material offers a loss factor (η > 0.2), converting vibrational energy into heat. Applied to battery casings or chassis, it reduces low-frequency noise by up to 15 dB, enhancing structural integrity and ride quality. Its resistance to temperature fluctuations and automotive fluids ensures durability in EV environments, while eco-friendly materials align with ISO 14001 standards.

In practical applications, Sontech’s solutions have lowered cabin SPL by 10–20 dB in EVs, meeting standards like ECE R138 for quiet vehicles. By integrating Acustimet® and VIBRALON 25 SB with optimized enclosure designs, we provide comprehensive noise control, improving driver comfort and battery longevity. Our materials are also recyclable, supporting the sustainability goals of the EV industry.

Why Choose Sontech for EV Soundproofing?