A control apparatus, that can expand a range in which noise generated in an unmanned flying object is reduced, is provided. The control apparatus acquires position information of one or more unmanned flying objects and noise information concerning first noises generated by the one or more unmanned flying objects. The control apparatus also acquires output region information indicating an output region of sound output from a speaker. The control apparatus calculates, using the position information, the output region information, and the noise information, second noises that reach the output region. The second noises are caused by the first noises which are generated by the one or more unmanned flying objects. The control apparatus generates opposite phase signals for outputting opposite phase sounds with respect to the calculated second noises, and causes the speaker to output sound on a basis of the generated opposite phase signals.