Abstract
The aim of this paper is to explore the sound energy distribution in cuboid extra-large spaces. The surface absorption and height are studied as the parameters using the image method. Air absorption is also discussed in this paper. The results show that the difficulty of reducing the noise increases with the increasing volume in extra-large spaces. Even if the ratio between the equivalent absorption area and the total surface is kept constant, the efficiency of noise reduction decreases by approximately 21% in this study. The absorption areas on the floor and the walls have a better performance on noise reduction than that on the ceiling. When the initial height of an extra-large space with general ratio of three dimensions is continuously halved, the variation in the noise level is close to a fixed value, and when the initial height continuously doubled, the noise level decreased approximately exponentially. The predicted difference between with and without consideration of air absorption increases linearly with the source-receiver distance.
