A control device includes an acquisition unit configured to acquire a position at which one or more occupants of a vehicle are seated, and a controller configured to determine necessity of reduction of noise of a drive source of the vehicle based on a distance between the position and the drive source of the vehicle, and reduce the noise by controlling the drive source according to a determination result of the necessity of the reduction of the noise.

In a hydraulic supply apparatus, one or more fitting grooves are formed along the outer circumferential surface of a ball nut, and corresponding fitting protrusions are formed on the inner circumferential surface of a damper coupled to the ball nut. This configuration minimizes damper movement, thereby reducing vibration and noise caused by collision with a bushing member during axial movement of the ball nut.

An assembled body includes: a back door of a vehicle, the back door including an internal space; a subwoofer attached to the back door, a front face of the subwoofer being oriented to the outside of the back door, a back face of the subwoofer being oriented to an internal space side of the back door; and an exciter attached to the back door, the exciter generating an output for cancelling vibration of an installation spot due to the subwoofer.