An earmold, including retention flaps to more securely hold an audio device coupled to the earmold, is provided. These materials include three-dimensional structures of interconnected ligaments, which have multiple concentric layers alternating between stiff constraining layers and soft damping layers, so that bulk deformation of the structure results in high local shear strain and correspondingly high bulk damping. The metal fittings carry the high bearing loads that are transmitted into the pylon at the engine-pylon and wing-pylon interfaces.