Abstract
Active noise control (ANC), that is one of active control methods to reduce the noise using the interference of sound, is applied to suppress the noise around the operator of agricultural machinery. In this paper, two target systems were developed. While one has the same method of f eedforward control as the evaluation system stated in the previous paper, the other has the method of feedback control. The performance of these target systems to reduce the noise was confirmed by the experiment with two tractors. The amount of noise reduction was about 10dB at the error microphone and about 4-6dB at the operator's ear in sound pressure level, and was about 1-2dB(A) in A-weighted one because of the effective frequency range of ANC that is less than 500Hz.
