Contribution of long flanking paths to sound transmission in buildings

Recent developments in calculation models for sound transmission in buildings have concentrated on the direct path and the flanking paths that cross only one structural joint. However, in real buildings there will be many other paths involving transmission across more than 1 structural joint and although these paths individually will be relatively unimportant their overall contribution can be significant. A number of numerical case studies were undertaken and it is shown that for many cases these longer paths are together more important than the first order flanking paths which in turn are often more important than the direct path. This suggests that although including first order flanking paths into a mathematical model will improve the agreement between measured and predicted data large errors may still occur if other parts of the building are not included.