Comparing Noise Profiles of Combustion, Battery, and Fuel Cell Vehicles
Internal combustion engines (ICEs) generate noise primarily from combustion, mechanical components, exhaust, and intake processes. This noise is controlled through a combination of passive measures—such as mufflers, acoustic insulation, vibration-damping materials, and engine mounts—and active techniques like active noise cancellation and piezoelectric actuators. These methods reduce sound levels significantly while meeting strict regulatory limits, though ICE vehicles remain relatively loud, especially during acceleration. In contrast, battery electric vehicles (BEVs) eliminate combustion entirely, relying on electric motors that produce only subtle high-frequency whines, gear noise, and auxiliary sounds from cooling systems. This results in substantially lower noise levels—often 5–20 dB quieter than ICEs at low speeds—enhancing cabin comfort and reducing urban noise pollution. BEVs also require artificial external sounds for pedestrian safety at low speeds. Fuel cell electric vehicles (FCEVs) share BEVs’ quiet electric drivetrain but add auxiliary noises from air compressors, hydrogen pumps, and cooling fans. However, they remain much quieter than ICEs overall, with noise dominated by high-frequency sources rather than low-frequency rumbles. Comparatively, ICE vehicles produce 65–80 dB(A) during acceleration, while BEVs and FCEVs typically range from 50–70 dB(A), with differences most noticeable below 50 km/h. At higher speeds, tire and aerodynamic noise dominate across all types, narrowing the gap. The transition to electric propulsion promises quieter cities, improved quality of life, and reduced environmental noise impact, marking a fundamental shift in automotive acoustics.