PURPOSE: To follow up even abrupt variation in the frequency of a noise as to a noise controller which eliminates a noise by outputting to a noise detected by a microphone a signal of opposite-phase sound pressure, etc., from a speaker.

CONSTITUTION: This noise controller is provided with a difference signal arithmetic means 5 which calculates the difference signal between the output of a sound wave/ signal converter 2 and the output of an adaptive filtering means 6, a transmission characteristic simulating means 4 which is interposed between the adaptive filtering means 6 and difference signal arithmetic means 5 and simulates the transmission characteristics of the system extending from the filtering means 6 to the difference signal arithmetic means through an electric signal/sound wave converter 3 and a sound wave/electricity converter, a period detection part 7 which detects the noise period of the noise 1 of a noise generation source 1, and a period adjustment part 8 which varies the period of the output signal of the difference signal arithmetic means 5 according to the quantity of variation in noise period; and the adaptive filtering means 6 calculates a compensation signal for outputting a compensated sound wave from the electric signal/sound wave converter 3 according to the output signal of the period adjustment part 8 and the output of the sound wave/electric signal converter 2.