A ceiling tile of gypsum and cellulose fibers formed into a board by
initially mixing the fibers and gypsum in a water-based slurry that is
felted and thereafter pressed and dried with a desired board thickness,
the dried board being processed to form a plurality of holes in a face
thereof through at least the majority of the thickness of the board, the
collective volume of the holes being sufficient to reduce the weight of
the board by at least 10% and increase the NRC exhibited by the board
over that which would otherwise be found in a board of the same
composition without such holes.