Brief Introduction to Active Noise Control in Cars

Active noise control (ANC), is a method for reducing unwanted sound based on destructive interference between offending primary noise and secondary “antinoise”. Noise in car interior is composed of induction noise, exhaust noise, noise from accessories, tire noise and noise radiation from engine sources. This paper reviews basic concepts of ANC applied to a car. Noise reduction is achieved by introduction of ANC system as an addition to existing conventional passive approaches. ANC in cars is quite successful at canceling tonal and low frequency noises. Reduction of lower mid frequencies could be achieved by ANC implemented by active headrests, with virtual microphones and even head position tracking.