NOISE CONTROL SYSTEM, AND FAN STRUCTURE AND OUTDOOR UNIT OF AIR-CONDITIONING-APPARATUS EACH EQUIPPED THEREWITH

摘要

To provide a noise control system capable of generating a noise cancellation field where noise is reduced at a desired position in a space. An error scanning filter generates a noise cancellation signal using an adaptive control algorithm based on error scanning, the signal having a phase opposite to that of an acoustic signal component detected by a reference sensor. A control speaker radiates the noise cancellation signal to create a noise cancellation field near the head of a person receiving sound.