Apparatus for removable attachment to a rigid surface for vibrating the same comprising a vacuum plate having a face with an elastomeric gasket around the face periphery and contactable with said rigid surface; a vibrator mount on the vacuum plate; a vibrator joined to the vibrator mount; and said elastomeric gasket projecting sufficiently forward from the vibrator mount and the vacuum plate to prevent the vibrator mount and the vacuum plate from touching the rigid surface when attached thereto so that all vibrations developed by the vibrator are transmitted to the rigid surface through the elastomeric gasket and the pressure waves in the vacuum plate.