Todays spatial acoustics occur more or less by chance of construction, its conscious creation is hardly part of architectural praxis. The present thesis wants to contribute to an auditive creation of room by offering a theoretical and empirical basis. It contains the issues perception of environment, perception of room and the human ability to hear a room. Gender-related differences in reference to spatiality will also be considered. Based on the facts, that each room contains a certain background noise, and that room size is a very important physical and emotional aspect of room, an empirical study will be conducted to proof three hypotheses. These hypotheses describe the influence of white noises damping, due to air absorption, and density, due to the behaviour of early reflections in a room, on perceived room size (verbal measure by the scales small-large and narrow-wide), and the influence of room size on emotional evaluation of room (measured by a semantic differential). The hypotheses were tested in an experiment; the results show an influence of damping on perceived room width, and an influence of density on perceived room size. Since the effect of density turned out to be contrary to the hypothesis and due to other leads, the operationalization of density has to be questioned. If subjects even perceived density as it was intended, will be discussed. Besides damping and density, the subjects sex turned out to be a relevant influencing factor. The obtained results will be interpreted in detail. Given that there lies realistic potential in a construction of room by sound, further parameters for auditive creation of room should be found and tested. The present thesis will also give possibilities of application, like individual modification of rooms spatial acoustics due to time of day or time of the year.