| Title |
Objective and Subjective Evaluations of a Scattered Sound Field Using a Scale Model |
| Authors |
Jeon Jin-Yong ; Ryu Jong-Kwan ; Kim Yong-Hee |
| Keywords |
Room Acoustics ; Diffusion(Scattering) ; Diffuser ; Scale Model |
| Abstract |
The acoustic properties of a multi-purpose hall were measured in a 1:10 scale model to investigate the effect of scattered reflections on its opera mode. Acoustical characteristics were measured in stalls area both with and with out diffusers on the walls adjacent to the pit and on the side walls. Approximately 40 % of the wall area was covered with diffusers. The diffusers consisted of 15-25 cm high hemispheres and 30 cm high polygons with an effective range of 1 to 2 kHz. The results showed that SPL, RT and EDT decreased at most seats due to the absorption of the diffusers and C80 increased at the front seats. The delay time between the direct sound and the reflection with maximum amplitude (ITDG) was delayed at the rear seat positions due to a change in the amplitude of the first reflection sound by the installed diffuser. It was also found that the installation of diffusers in several positions close to the walls adjacent to the pit decreased 1-IACCE3. The difference in 1-IACCE3 between with and without diffuser was larger than that in 1-IACCL3. Amplitude and delay time of the first reflection were reduced by installing diffusers. Subjective evaluations showed that the diffusers on the side wall improve the auditory preference in the area around them. It was also found that significant factors for preference of scattered sound are IACC and EDT. |