Investigating the Sound Absorption Performance of Circular and Slotted Perforated Birch (Betula platyphylla) Plywood as Interior Building Materials

The use of perforated plywood as an interior architectural sound -absorbing material has been increasing in popularity in Korea. This study investigated the sound absorption performance of marketed birch (Betula platyphylla) plywood with circular and slotted perforations using the sound absorption measurement method (KS F 2805) in a reverberation chamber with a 300 mm backspace. The results showed that unperforated birch plywood absorbed little sound. However, birch plywood with perforation levels of 1.77%, 5.77%, and 7.76% showed significant sound absorption. The noise reduction coefficient (NRC) of perforated birch plywood was 0.4 to 0.6. The results were 0.3 S to 0.5 S sound absorption grade by KS F 3503. The optimal perforation level was 5.77%. These findings can aid in expanding the wood sound absorption market.