NOISE REDUCING DEVICE

PROBLEM TO BE SOLVED: To provide a noise reducing device capable of constantly obtaining the silencing effect against the fluctuation of the noise frequency to the environmental change or the aging effect without increasing the cost for expensive parts such as a DSP or development of complicated algorithm and without increasing the time for development of a device. SOLUTION: The angle signal to be outputted by a noise detecting means 40 to detect the noise is converted into the digital data, the output data of an A/D conversion part 60 corresponding to the condition of the drive control signal is stored in a storage means respectively in a storage/reproduction part 70 at the beginning of the operation of a device or at the prescribed intervals, the data corresponding to the condition of the drive control signal is outputted from the storage means when the device is subsequently operated, the digital data to be generated from the storage means is converted into the analog signal, and the signal of the inverted phase where the phase of the analog signal is inverted, is generated, and the inverted signal is converted into the acoustic signal, and outputted.