GREETING CARD HAVING A LOUDSPEAKER COMPRISING A BOARD HAVING CAPABILITY TO SUSTAIN AND PROPAGATE INPUT VIBRATIONAL ENERGY

摘要

A greetings or the like card (144), characterised by a board (2) forming at least part of the card and in that the board is a distributed mode acoustic radiator having a transducer (9) mounted wholly and exclusively on the radiator to vibrate the radiator to cause it to resonate.