It should be borne in mind that spoken communication not only takes place in "function rooms", but in all locations where people congregate, for example: hallways, lobbies, recreation halls. The standard DIN 18041 considers the current state of knowledge regarding audibility and inclusion. A fully scientifically justifiable derivation of exact numerical values requirement for this is currently unknown. We know, however, that a strong absorption is a favorable effect on the audibility. DIN 18041 specifies acoustic specifications and instructions for th eroom acoustic design to ensure good acoustic quality, primarily of spoken communication, in rooms. It applies to small to medium-sized rooms with a room volume up to about 5000 m, and to sports halls and swimming baths without public present up to 30000 m in volume. A differentiation is made between acoustic quality over medium and large distances, for instance classrooms and children's day care centers, and over small distances, for instance in eating places and public areas. The standard does not cover the acoustic quality of rooms with special requirements, such as theatres, concert halls, in rooms for the high-quality recording of music and speech as well as dwellings.