Adaptive Cancellation of Engine Noise in Vehicle Cabin

This paper presents the adaptive noise canceller for the suppression of noise caused by a rotated engine in a vehicle cabin. The canceller uses two microphones to accept the background signals for the processing. One microphone is installed close to the vehicle engine, i.e. outside the cabin. It allows to isolate this microphone from the near-end speaker's voice which is accepted by the second microphone and is transmitted to the far-end speaker. At the same time, the engine noise penetrates to the cabin and is accepted by the second microphone. As a result, the transmitted voice signal becomes noisy. This noise has to be cancelled priory the voice signal transmitting. Because the engine noise is rather colored than white, the efficiency of usage in the noise canceller the computationally simple adaptive filters based the gradient search is low. This paper considers the usage of the computationally complex but functionally efficient Recursive Least Squares (RLS) adaptive filters in this task. Simulation demonstrates a better performance of the RLS noise canceller comparing to the gradient search based Normalized Least Mean Square (NLMS) noise canceller in the considered scenario.