ACTIVE NOISE REDUCING DEVICE

摘要

PROBLEM TO BE SOLVED: To provide a practically excellent active noise reducing device that causes no sense of incongruity in listening sense without producing distortion in an electroacoustic transducing means even when an excess noise signal at a very low frequency region comes. SOLUTION: The active noise reducing device consists of a noise detection means 101 that detects a noise, an interference generating means 102 that receives a signal from the noise detection means 101 and generates an interference signal not interfered with the noise, a limit amplifier means 103 that receives a signal from the interference generating means 102 and amplifies an input signal at an amplification factor varied in response to the level of the input signal so that a threshold reaches an upper limit of the amplitude when the amplitude of its output signal is a predetermined threshold or over, and an electroacoustic transducer means 104 that receives an output signal from the limit amplifier means 103 and emits an interference wave.