Abstract: A method and system (50) for inducing multi-frequency vibrations in a vibration propagating structure, for example a seat (52), is disclosed. The system is comprised of an acoustic vibration transducer unit (12) mounted on a relatively flat and rigid surface (54?) such that the direction of movement of an actuating element in the unit is parallel to the surface. When the unit is driven by an amplified low frequency audio signal a person sitting in the seat experiences vibrations. Additionally, a series of vibration propagating structures, for example a row of seats at a movie theatre, can be connected in series via vibration-propagating members (60) between adjacent seats thereby allowing a single acoustic vibration transducer unit to propagate vibrations to all connected seats.