An energy absorber includes a base sheet and a plurality of energy absorbing units with domed countermeasures extending from the base sheet. The countermeasures have slits in a domed portion thereof. The side walls of the energy absorbing units protect an adjacent object by cushioning the blow following repeated impacts in both vehicular and non-vehicular (e.g. helmets) environments. Preferably the side walls are oriented to buckle or bend after absorbing energy when impacted. The countermeasures primarily deaden any associated buzzes, squeaks or rattles. The integrally-formed countermeasures have a lower standing strength than the energy absorbing units. Methods related to the above are also described.