Abstract: Vibrating membrane horn of the type wherein a membrane is applied on a peripheral flange on a case in such a way as to close said case. Said case contains a vibrations generator acting on said membrane and a gasket is interposed between said membrane and said flange. Said gasket consists of an absorbent material impregnated with a water-proofing product.

Abstract: An electro-acoustic signalling horn of the type comprising a case containing an electromagnetic excitation system, a diaphragm subjected to the action of said system, and a sound amplifying box extending a labyrinth chamber. Said box is in a single moulded piece and has a lateral opening opening into said chamber and adapted to receive the diaphragm and the case. Said diaphragm and said case are rendered integral by a metal plate having an edge portion formed over onto a peripheral portion of the diaphragm and the case, the assembly comprising the case, the diaphragm and the plate being maintained in said opening by adhesion of the plate to the adjacent portion of the labyrinth chamber and cooperation of the formed-over peripheral portion of the plate with the edge of the opening.