Sensor configuration efficiency and robustness against spatial error in the primary field for active sound control

The efficiency and the robustness of active noise control against fluctuati ons depend, amongst other things, on the secondary source and control micro phone configurations. Within the context of harmonic sound attenuation, the performance (efficiency and robustness) according to the source configurat ions has recently been dealt with. The present study is focused on the perf ormance according to microphone, or sensor, configurations. It is demonstra ted that all sensor configurations may become equally efficient due to the fact that they may be made to control equally well a domain defined by a ce rtain number of observation points. The paper also gives a definition of ro bustness starting from the result of previous work on source configurations . Robustness is understood here in relation to the spatial fluctuations of the primary sound field. Given this definition, indications are provided fo r choosing the most robust sensor configuration or how to improve the robus tness of any one of the sensor configurations. (C) 2001 Academic Press.