Effect of the suspended ceiling with low-frequency resonant panel absorber on heavyweight floor impact sound in the building

This study investigated the effect of the suspended ceiling panel with low-frequency resonant panel absorber on heavyweight floor impact sound. The resonant panel absorber was designed with a perforated top panel, an air gap with or without glass wool, and a bottom panel to ensure a high absorption coefficient in the low-frequency range around 100 Hz. Absorption coefficient measurements were carried out first in the reverberation chamber for resonant panel absorbers varying with the hole diameter of the top panel, the thickness of the glass wool and the air gap between the top and bottom board. As a result, the glass wool had the greatest influence on the absorption coefficient, and the highest absorption coefficient of the resonant panel absorber was about 0.6 in the band of 100 Hz. Floor impact sounds after installing the suspended ceiling with the best resonant panel absorber were also measured in test building using heavyweight floor impact sound sources (bang machine and rubber ball) and compared with result for normal suspended ceiling with gypsum board. Heavyweight floor impact sound by the resonant panel absorber was decreased by 2 dB and 4 dB in single number quantity (Li,Fmax,Aw) for bang machine and rubber ball, respectively. In particular, the resonant panel absorber reduced by 6 dB in 125 Hz octave band with the largest absorption coefficient.