Block diagram of the implementation of the object and surface scattering module (thick red and blue components, respectively) in the framework of the room acoustics simulator RAZR (thin lines) consisting of the ISM (light red block) and FDN (light blue block) module. For object scattering, the IS signals are subjected to cascaded all-pass filters APC^O (red). Consecutively, the outputs are separated into specular and non-specular reflected parts by the decomposition filters H^σ(f) and H^δ(f) (blue). Additionally, the non-specular part is temporally diffused by Schroeder-reverberators with cascaded all-pass filters APC^S (blue).