The contributions of resonant and non-resonant components to the overall sound transmission through a finite panel have been studied numerically. It was seen that the fundamental mode makes a significant contribution to the non-resonant sound transmission through a finite panel. Therefore, the non-resonant sound transmission loss of a finite panel can be determined, when using a coupled finite element/boundary element analysis, by constructing a structural model with only the fundamental mode in the modal database. The sound transmission loss obtained using this method represents the non-resonant transmission loss of the panel at all frequencies apart from those in the vicinity of the natural frequency of the fundamental mode. The analysis of panels containing higher order modes showed that these modes only contribute to the overall sound transmission loss of a panel at frequencies close to their natural frequencies. The resonant contribution of these higher order modes is reduced by the presence of damping.