Acoustic properties of gypsum-palm panel and foam concrete-palm panel

This study aims to determine the acoustic properties of gypsum panel, gypsum-ijuk panel, ijuk-gypsum panel, foam concrete panel, and foam concrete-ijuk panel. The size of panel was 1 m x 1 m with a thickness of 0.02 - 0.03 m. The measurement of the sound absorption coefficient was carried out using the reverberation chamber method (ISO 354-1985) for the frequency range of 125 – 4000 Hz. The results showed that the sound absorption coefficient fluctuated with frequency. Gypsum panel has the highest sound absorption coefficient of 0.42 at 125 Hz and the lowest 0.05 at 400 Hz. Ijuk panel has the highest sound absorption coefficient at 2000 Hz which is 0.97 and the lowest at 200 Hz which is 0.09. The sound absorption coefficient of the combined panel of ijuk with gypsum (ijuk above and gypsum below) is 0.85 at 2500 Hz and 0.06 at 315 Hz. Gypsum and ijuk composite panels (gypsum above and ijuk below) have the highest sound absorption coefficient of 0.93 at 125 Hz and 0.09 at 315 Hz. Foam concrete panel has the highest sound absorption coefficient at 160 Hz with a value of 0.91 and the lowest at a frequency of 315 Hz with a value of 0.08. Foam concrete panel combined with palm oil (foam concrete on top and ijuk below), the sound absorption coefficient is 0.86 at 800 Hz and 0.15 at 500 Hz. The results of this study show that the sound absorption coefficient can be improved by combining a number of materials. Composite panels of foam concrete-ijuk and gypsum-ijuk have the potential to be applied for sound absorber materials.