Sound absorbing ceiling to reduce heavy weight floor impact sound

This study aims to reduce heavy weight impact sound, changing the sound field by applying sound absorbing ceiling. Sound absorption performance is reviewed at the reverberation chamber, and the ceiling is designed to be higher than the sound absorption coefficient of a commercial base trap. As a result of applying this to apartment households, the heavy weight impact sound evaluated using a bang machine was reduced from 4.6 dB at 63Hz to 2.2 dB at 125Hz of 1/1 octave band, and the single number quantity (L-i,L-Fmax,L-AW) was reduced by 3 dB. When evaluated using a rubber ball, the noise level reduced to 4.9 dB at 63Hz and to 1.8 dB at 125Hz. The single number quantity was reduced by 2 dB. When the sound absorbing ceiling and the bass trap were installed together, there was an additional reduction of 3 dB for a bang machine and 2 dB for the rubber ball. As a result of mode analysis, the sound pressure level reduced at 63-125Hz frequency range, and the uneven phenomenon was alleviated.