抄録
In general, the sound waves propagate spherically in free space, which accordingly makes the global attenuation difficult. Placing number of microphones and control sources can improve the range of quiet zones and several studies have been done to this end, yet still limitations on implementation and cost cannot be neglected. In the present study, a new approach for active control of sound in free space is developed using high directional parametric loudspeaker as the control source. Both normal and the parametric loudspeakers are applied as control sources and results are compared based on measurement of interfered sound field. It is known that the suggested ANC system can mitigate sound locally but cause less influence on sound field in circumferential space.
