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 fluctuations depend, amongst other things, on the secondary source and control microphone configurations. Within the context of harmonic sound attenuation, the performance (efficiency and robustness) according to the source configurations has recently been dealt with. The present study is focused on the performance according to microphone, or sensor, configurations. It is demonstrated 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 certain number of observation points. The paper also gives a definition of robustness 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 for choosing the most robust sensor configuration or how to improve the robustness of any one of the sensor configurations.