A sound-absorbent plaster. Acoustical plasters, developed in the 1920s, were made porous and sound-absorbing by the incorporation of fibrous or porous aggregates, such as wood, mineral wool, cork or asbestos. An alternative method called Hushkote, incorporated yeast in the plaster mixture to generate bubbles that would increase the porosity. By 1945, spray-applied acoustical coatings were available (Spray-Acoustic). These generally incorporated mineral wool or asbestos in a fireproof binder. Synonyms: Sabinite plaster; Akoustilith plaster; Macoustic; Kilnoise; Kalite; Hushkote. Museum of Fine Arts, Boston (2000). [J. Cassar, R. de Angelis]