According to the present disclosure, an additional sound generating unit detects, as a noise frequency, a frequency of a noise at a control point and generates an additional sound signal including signal components with additional frequencies different from the noise frequency. A canceling signal generating unit generates a canceling signal that cancels the noise at the control point. An emission unit outputs a control sound signal, generated by adding the additional sound signal to the canceling signal, to a loudspeaker and makes the loudspeaker emit the control sound.