This invention relates to a method of using a previously known sound arrangement in a new way.

By European patent 0391933 BI is previously known a sound arrangement, which is intended to be used in a ceiling in a space intended for people. This sound arrangement is arranged in that way that it comprises at least 10 loud speakers per square meter. Furthermore, the effective area of the sound-ceiling shall be at least 5 square meters. With effective area of a sound-ceiling is meant the area of that part of the ceiling where the main part of the loud speakers are positioned. This means that if the area of the sound-ceiling is 5 square meters, the number of loud speakers shall be at least 50. Due to this arrangement the great advantage is achieved that the propagation of the sound laterally is reduced to a minimum.

In later times the effect of the sound-amplifiers has become higher and the efficiency and the effect-durability of the loud speakers have become higher. This fact has had the consequence that the sound levels and by that the sound disturbances on the audience have increased strongly when using conventional sound installations. For these reasons an introduction of sound limitations on public places is discussed, for instance when having amusement arrangements.

It has further become more common to create so called film cities, meaning that a large film hall has been divided into a number of smaller rooms, different films simultane- ously being able to be shown in the different hall parts. A problem in this connection, however, has been the fact that the sound normally is also propagated laterally. Therefore it has been necessary to arrange expensive, well-isolated partition walls between the different hall parts.

By using the sound-ceiling, mentioned in the introduction, in a new way, the problems with known technique can be eliminated.

According to the invention an essentially vertical wall is arranged in a space or at a meeting place for people. This space can be a cinema hall, a concert hall or the like. In this connection the wall can be a front wall, a side wall or a wall at the very back of the hall.

According to the invention the known sound arrangement could also be used on an essentially vertical wall of an outdoor stage. In this connection the sound- wall should suitably be positioned behind the band playing on the stage or behind the person or those persons acting on the stage. The loud speakers of the sound-wall should be so positioned that they were directed towards the audience/the listeners.

With a sound-wall according to the invention a directional influence on the sound streaming out from the loud speakers of the sound- wall is achieved, so that the sound goes essentially straightly out from the sound- wall with a minimum of lateral propagation. Of course, this means that when using the sound- walls according to the invention in film cities, it is no longer necessary to have expensive wall isolations between the different hall parts. Furthermore, the use of a sound- wall means that the sound gets a satisfactory propagation straightly forwards without the penetrating sound being felt as disturbing.

In the text has been mentioned "an essentially vertical" wall. Of course, within the scope of the invention other types of walls are spaced, for instance inclined walls.