An adjustable mattress foundation includes a frame having at least one movable frame portion, a panel coupled for movement with the movable frame portion, an actuator supported upon the frame and operable to selectively incline the at least one movable frame portion, and a vibration motor assembly coupled to the panel. The vibration motor assembly includes a vibration motor and a cover at least partially enclosing the vibration motor. The cover includes an outer shell and a liner at least partially positioned within the outer shell.
