Acoustical panel having a honeycomb structure and method of making the same

An acoustically absorbent porous panel with a layer constructed from a substantially continuous open-celled porous material comprising a cured foamed cementitious material including a first face and a second face. The first face has a surface with a substantially planar profile and the second face has a substantially geometric pattern of depressions formed therein comprising approximately 50% to approximately 90% of the layer by volume.