On the performance of a hybrid (intensity – MISO) method to identify and locate noise sources in a wood processing centre.

An array composed of 16 intensity probes has been applied to a complex CNC wood machining centre to identify and locate the principal noise sources. The initial investigations have suggested a significant radiation from the moving head panels. Intensity measurements do not distinguish noise sources at various spatial planes. Therefore, the sound intensity technique has been coupled here, with the multiple partially coherent inputs method (MISO.) This hybrid approach enables to separate the panel contributions from those of the ‘internal’ sources of the CNC’s moving head. Both techniques present some limitations: at very low frequencies in the case of MISO, the structure cannot properly be excited and at high frequencies the structure movements may lower the precision of the intensity measurements. The results show the efficiency of array intensity technique and the adaptability of the associated instrumentation to acoustic holography methods.