ELECTRONIC MUFFLING SYSTEM

摘要

PROBLEM TO BE SOLVED: To realize an active muffling control of the ducts obtained by dividing a large diameter duct and to improve the muffling performance at a low cost. SOLUTION: A sensor microphone 10A is arranged in one of the ducts which is the reference among the ducts that are obtained by dividing a large diameter duct. Error microphones 14A to 14D are arranged in all divided ducts. Then, the residual noise signals from the microphones 14A to 14D are added in an adder 46 and added to a computing circuit 36 in one controller 40. Thus, only one controller 40 is enough and the muffling effect on the entire ducts as a whole is improved.