Barking Box

This metal cube, 6 inches on a side, has a crank on top. Using an action to wind the crank activates the box for 8 hours. While activated, the box barks whenever it detects vibrations within 15 feet of it, as long as the box and the source of the vibrations are in contact with the same ground or substance. A switch on one side of the box sets the device to emit either a small dog's bark or a large dog's bark.