Adjustment of the Reverberation Time and Dimensions in the Reverberation Chamber for the Reduction of the Measurement Dispersion

Current standards, like ISO 354, ISO 17497-1 or ISO 3741 contain few requirements for the reverberation chambers. Despite the included qualification methods, results obtained in measurements in different chambers can be different by 30%. Chambers' shapes and types vary a lot around the world, which show the lack of important designing criteria, parameters included in current standards doesn't describe exact sound field diffuseness level and are based on old assumptions, like papers from 60s from last century. Verification of the ISO standards parameters is required, also introducing extra parameters describing the level of sound field diffuseness. Model and experimental studies have been conducted using the ray-tracing method in order to verify the level of sound field diffuseness in varying versions of irregular reverberation chamber. Previous research over this topic proved that statistical methods are usable for reverberation chamber rating, this paper will be focused on rating with reverberation time and reflection in-time analysis. Results obtained in both experimental and model studies will be explained and they usability in reverberation chambers designing.