Performance evaluation of an active headrest using the remote microphone technique

Abstract

Active headrests produce a quiet zone near the occupant's head using active noise control. It has been shown that active headrest algorithms using virtual microphones are better than those using physical microphones, as they have the ability to shift the zone of quiet away from the location of the physical microphones towards the ears of the occupant. Recently, the virtual microphone arrangement based ANC method was used for an active headrest application, in which it was assumed that the primary pressures at the physical and virtual microphone locations are similar. In this paper the previous work is extended to incorporate the remote microphone technique, which is a better estimation algorithm as it incorporates an extra transfer function between the physical and virtual microphone. Experiments using two secondary speakers, and two physical and two virtual microphones are carried out to compare the results from both algorithms. The paper comprises of the detailed multichannel virtual microphone algorithm for a headrest and the experimental results.