1996 Volume 58 Issue 1 Pages 57-63
Using the feedback type active-noise-control (ANC) techniques based on sound interference effects, the reduction of noise level around the operator of agricultural machinery was investigated. This paper described a method of feedback control system compiling RLS (Recursive Least Square) algorithms on a high speed DSP (Digital Signal Processor), and noise control experiments on a tractor to estimate the proposed nois control system. This system was brought about a noise level reduction around the operator's head by 5-6dB over a range of test frequencies, especially by about 14dB at a frequency of the maximal sound pressure level.
