Active noise control in agricultural machines

Agricultural machines generate a complex noise field with significant low-frequency components. The demands for good sound comfort of the driver inside cabins of these machines are continuously growing. Since passive control techniques are not able to efficiently reduce the low-frequency noise in the cabin, active noise control techniques are being explored. A zone of quiet around the ears of the driver is quested through the use of secondary loudspeakers. This paper studies three different control strategies: feedforward control, feedforward control with feedback compensation and feedback control. The practical setup and the control algorithm of each control technique is discussed. The practical results, the advantages and the restrictions of the three techniques are compared.status: publishe