  Construction workers and residents live near around construction sites are
exposed to noises that might cause hearing loss, high blood pressure, heart
disease, sleep disturbance and stress. Regulations has been carried out by
national governments to limit the maximum permissible noise levels for
construction works. A four-channel active noise control system mounted on the
opening of an enclosure is designed to prevent the machinery noise from
spreading around and retaining the heat diffusion path. Multi-channel FxLMS
algorithm in time domain is implemented on the main controller. A Genelec
speaker is placed inside the box as the primary noise source to play back
different types of noises. Analyses and experiments are carried out to
investigate the controllable frequency range of this ANC system in detail.
Considerable noise reduction performance is achieved for different recorded
practical construction noises.
