Acoustic modeling of sequential spaces: A parametric study

Sound field modelling of sequential spaces is required for large-scale public buildings. A FEM model comprising five successive rooms was used for a parametric study considering, i.e., contextual (opening dimension and position, number of rooms), acoustical (absorption coefficient and position) and source (directional radiation of opening and additional source) factors. The results reveal that (i) In rooms with high absorption, the average SPL of the rooms is higher, and the level difference between rooms is smaller with a larger opening dimension. Opening position only has impact for rooms with low absorption. (ii) The level differences between rooms are larger for oblique radiation compared to horizontal radiation, especially for rooms close to source. With an additional source (e.g., HVAC system and human speech) in a room, the level in this room is kept or reduced by approximately 10 dB with increasing opening dimension for rooms with high or low absorption, whereas the levels in other rooms increase for rooms with high absorption. (iii) The changes achieved by absorption are more significant with low absorption. The difference in the SPL between uniform and non-uniform absorption distribution with a given absorption amount is greater with a smaller opening dimension. (iv) The effects on the SPL in the first receiving room, caused by adding more sequential rooms, is less when the absorption in those rooms is high (e.g., with an absorption coefficient of 0.5), and the difference between different absorption coefficients is about 6 dB maximum, depending on the number of rooms