Abstract: An energy absorption material for covering a rigid vehicle support surface provide impact protection for a vehicle occupant's head is a sheet of material formed into a waveform comprising a plurality of regular corrugations which have identical crests and valleys connected by inclined sidewalls. The material thickness of the crests and valleys is the same and thicker than that of the sidewall material. The crests and valleys are curved such that the inside radius of each of the crests is smaller than the inside radius of each of the valleys, so that the sidewalls adjacent a valley are laterally closer than the sidewalls adjacent a crest. The corrugations have a pitch equal to their height. This construction provides a deformation mode of the material in which the crests and valleys deform by bending and the sidewalls deform by buckling. The material can contain a plurality of perforations, covering 7%-15% of the area for sound absorption.