Journal of Korean Institute of Architectural Sustainable Environment and Building Systems ISSN:1976-6483(Print) 2586-0666(Online) 한국건축친환경설비학회논문집

In this study, the sound field according to the ceiling installation was confirmed by measuring the reverberation time, and the increase of sound absorption and the amount of noise reduction were predicted. In addition, predicted noise reduction according to changing reverberation time and measured noise reduction of floor impact sound according to the ceiling installation were compared. Two types of ceiling structure were used, “suspended ceiling” fixed directly to the slab and “wall supported ceiling” fixed to the wall. Porous absorbing material was additionally installed in the “wall supported ceiling”. In a space with a long reverberation time, it was confirmed that the porous sound absorbing material behind the unperforated gypsum board affects the reduction of the reverberation time from 8 s to 2 s at 63 Hz. In a space with a reverberation time of 0.8 to 1.2 s, it was confirmed that the difference in reverberation time according to the installation of the sound absorbing material behind the ceiling was about 0.1 to 0.2 s. The correlation between the floor impact sound reduction according to the increase in sound absorption of sound receiving room by excitation of the bang machine was R²=0.7889, p-value=0.0181 (<0.05) at 63 Hz, which showed a high correlation. This suggests that the improvement of floor impact sound insulation performance in the 63 Hz band can be expected by increasing the sound absorption of the sound receiving room. In addition, it indicates the need for correcting the reverberation time of the sound receiving room when evaluating the heavy weight impact sound insulation performance.