Review on active road noise cancellation technologies for vehicles

Tire/pavement noise is a dominant source of cabin noise in automobiles, characterized by low-frequency broadband features. Road noise cancellation technologies have been investigated over three decades and implemented in several mass-production vehicles. Although road noise cancellation systems can attenuate spectral peaks below 500 Hz by more than 10 dB, the overall sound pressure level reduction typically remains between 3 dBA and 4 dBA, leaving substantial performance gaps relative to user expectations. In this study, the generation mechanism and transmission pathways of road noise are first elucidated, and the noise-reduction metrics achieved by existing production vehicles are summarized. Subsequently, the architecture and operating principles of road noise cancellation systems are presented, followed by a systematic review of major research advances. Critical bottlenecks are highlighted, and future research directions are proposed. It is concluded that increasing the number of channels in the active noise cancellation system further or mitigating the uncertainty inherent in the acoustic transfer-path response must be achieved to further enhance the performance of production-grade road noise cancellation systems and to enable their wider commercial application.