Theoretical calculation and test of airborne sound insulation for wooden building floor

Abstract

To meet objectives such as the sound insulation characteristics of timber structures and the comfort of residents, this study assessed an ordinary floor and three kinds of floating floors (Portuguese cork, graphite polystyrene sound insulation boards and expanded polypropylene plastic foam boards) in the same bedroom of a two-storey light wooden building. Adopting standard white noise and music noise excitation, structural design, theoretical checks and sound insulation tests of the floors were conducted. For the four floor structures, the sound insulation volume, sound pressure distribution characteristic spectrum of the building floor under different noise source environments, the frequency characteristics of the noise source, the multiple relationship of the sound insulation sound pressure level and the sound insulation mechanism were analysed. It was found that the sound pressure multiple of the space separating the upper and lower floors of the building was 8–18 times greater than that of the light wooden floor structure. The airborne sound insulation volume–frequency curves of the four floors, calculated by the transfer matrix method, were consistent with the actual measured values. The sound insulation effect was better in the low and middle frequencies.