Abstract
The low frequency noise radiated from an engine is one of the social problems for environmental noise. The performance, in terms of power attenuation, of sound absorption materials or barriers is relatively poor at low frequencies. Therefore, the authors propose a method employing an active noise control for minimizing the total acoustic power radiated from an engine, leading to an environmental noise reduction in the entire area around an engine. Suitable arrangement of sources and error-microphone are investigated by the basis of theoretical estimation. The power attenuation effects of an engine was examined by simulation and experiment.