An acoustic protective panel for the fitting of a wall of a vehicle, has an upper porous layer, in particular with a felt or remelted flexible foam base, at least one zone of the porous layer being arranged on one sealing layer, the sealing layer being arranged on one backing layer (5) with a flexible polyurethane base forming a spring, said sealing layer being formed by impregnation on a portion of the thickness of the porous layer by the polyurethane of the backing layer overmolding the porous layer. Architectures for mounting such a panel are described.