Whenever workrooms or operating rooms are to be planned or redesigned, room acoustics should be given due consideration. With good room acoustics, even the operation of noisy machinery does not result in an excessive noise level in the room. The following noise abatement systems can be used: suspended sound absorbing elements, acoustic ceilings and panelling, perforated trapezoidal sheets. prefabricated roof elements, sprayed or glued cladding as well as special constructions. See also Noise Abatement.