The effect of boundary shape to acoustic parameters

Abstract

To design a room in term of acoustic, many variables need to be considered such as volume, acoustic characteristics & surface area of material and also boundary shape. Modifying each variable possibly change the sound field character. To find impact of boundary shape, every needed properties is simulated through acoustic prediction software. The simulation is using three models with different geometry (asymmetry and symmetry) to produce certain objective parameters. By applying just noticeable difference (JND), the effect is considered known. Furthermore, individual perception is needed to gain subjective parameter. The test is using recorded speech that is convoluted with room impulse of each model. The result indicates that 84% of participants could not recognize the speech which is emit from different geometry properties. In contrast, JND value of T30 is exceed 5%. But for D50, every model has JND below 5%.