The scattering coefficient is one of the most important input parameters in room acoustics simulations. Together with the absorption coefficient they belong to the main descriptors of interior surface properties in a calculation process based on ray or radiosity method algorithms. This contribution deals with the comparison of three predicting software and objective assessment of scattered sound in the example of a virtual concert hall. The influence of scattered sound on the objective room acoustical parameters like T30, EDT, C80, D50 and G, is investigated. Six different alternatives were simulated, where scattering coefficient values s = 10, 30, 50, 60, 70 and 90% respectively, were applied to the interior surfaces of the ceiling, side and rear walls. Analysis has been performed by studying the results of objective room acoustical parameters predicted by simulations done with the software Odeon® 10.1, Catt-Acoustic® v 8.0. and Rave