PURPOSE: To reduce the cost since no error detecting means is required for the normal operation of the air conditioner and to obtain the noise eliminating device which greatly eliminates of reduces a noise with high follow-up control since a control filter coefficient is updated as a sound wave propagation medium changes in state.
CONSTITUTION: The 1st signal showing characteristics of the noise and the 2nd signal showing characteristics of the state of the sound wave propagation medium are transmitted from a 1st detecting means 7 and a 2nd detecting means 8 to an electronic control means 9 respectively, and the optimum control filter coefficient which is determined previously for a certain state of the sound wave propagation medium is updated by a correcting means in the electronic control means 9 and outputted to a canceling means 6, thereby eliminating or reducing the noise with a canceling sound generated by the canceling means 6.
SHIMOIDE SHINICHI
IWASE KOJI
OKAMOTO JOJI
