An energy absorber includes a base sheet and a plurality of energy absorbing units with end walls and associated leaf spring or helicoid accessories extending from the base sheet. The accessories reduce buzzes, squeaks and rattles associated with an environment of use. In one embodiment, the leaf springs are defined by slits in a domed portion of the end walls. In another embodiment, the helicoid is formed by for example a milling step performed on an end wall. The side walls buckle or bend after absorbing energy. Methods related to the above are also described.