road noise cancellation (RNC)

Disturbing background noise and unwanted noise inside the car impair the driver's concentration, communication with passengers and the audio sound from high-quality audio systems. These disturbing exterior and interior noises, which are caused by the road surface, tires, wind and engine, must be reduced.

There are several technical approaches to noise reduction: road noise cancellation ( RNC), which reduces or cancels rolling noise, and engine order cancellation (EOC), which aims to reduce engine noise.

Road Noise Cancellation is concerned with rolling, road and tire noises that can be heard inside the car. These noises are reduced by acoustic countercompensation. They are recorded, rotated in phase and fed in counterphase via the acoustic system. As a result of the superimposition with the background noise, the latter is only perceptible in reduced form. This process ensures a lasting improvement of the background noise inside the car.

Engine Order Cancellation also works with noise compensation. However, the compensation signal is derived from the engine speed. This is used as a reference for the phase-rotated sound signal.