The movement of sound from a source to a listener is affected by the acoustics of the space through which the sound moves and the optimal acoustics for a space depends on what the space is intended to be used for. Theatres, for instance, have different requirements from offices, or large station concourses.
Each EU state has its own regulations with which building materials must comply. A distinction is made in this respect between construction materials and building elements such as facings and finishing materials.