ANC for road noise attenuation

This chapter presents an application of active noise control techniques for passenger comfort in cars. At the analysis stage nonstationary vibrations of the front and rear wheels are generated by nonuniform road profiles and change of vehicle speed. These propagate through the tyre and the complicated suspension system and finally generate structure-borne noise, impulsive noise, and other low-frequency noise in the interior of the passenger vehicle. These noises produce acoustical resonance in the interior of the passenger car and such resonant noise is called "road booming noise". Cancellation of this noise is the topic of this chapter.