| 摘要 |
PURPOSE:To obtain a duct sound elimination device, which has small restrictions on the arrangement of a sensor, a sound generator, etc., even in a large-diameter duct and is improved in sound elimination effect, by a simple device. CONSTITUTION:The sound signal from one upstream-side sensor 14a arranged upstream at a specific distance Ls from the upstream end of the partition plate 12 of the duct 13 is inputted to control means 30 and 28 of divided ducts, and actuators 11a and 11b of the divided ducts are arranged at a distance La longer than the specific distance Ls upstream from the upstream end of the partition plate 12, so the sound from the actuator 11b of the duct 13 reaches the upstream-side sensor 14a first and is put together with a noise into a synthesized wave, which is received by the upstream-side sensor 14a. The control means 30 or 28 of the divided ducts obtains the synthesized wave sound and generates sounds from the actuator 11a or 11b by noise control algorithm on the basis of the synthesized wave sound while referring to monitor sounds from downstream-side sensor 16a or sensor 16b. |
