A unit of land measurement equal to 43,560 sq ft or 4046.85 sq m; 1 sq mile (2.59 sq km) equals 640 […]

A special low-density soundabsorptive plaster, applied in the form of a finishcoat, to provide a continuous finished surface.

A model of an auditorium or room used to study certain acoustical properties of the full-sized enclosure, such as the

Any material especially designed to absorb sound.

An acoustical ceiling board designed to be laid into an exposed grid suspension system.

A porous material in board form, designed or used as an acoustical material or as an element in a sound-insulation construction.