Composite materials having favorable acoustic and vibration damping properties, while maintaining or improving other composite mechanical properties, include an interleaf layer comprising at least two different nonwoven materials in a specific sequence such that a gradient is formed in the z direction upon curing or an interleaf with a compositional gradient within its structure such that a resin interpenetration gradient is achieved upon curing. Composite materials that contain multilayered nonwoven interleaves are useful, for example, in structures found in aircrafts, such as fuselage skins, stringers and frames. Also contemplated are methods of making the composite material and the structures and aircrafts that contain the composite material.