Sound absorption characteristics of three species (binuang, balsa and paulownia) of low density hardwood

Abstract In this study, the sound absorption coefficient of three low density hardwoods – binuang, balsa and paulownia were investigated. Their gas permeability pore size measured, their shapes classified into through pore, blind pored, closed as specified by International Union Pure Applied Chemistry (IUPAC). Among species, obvious that had lowest when two others showed higher absorption. Although is a high porosity wood, most its vessels are blocked tyloses; it therefore difficult for waves to enter pores, which results in poor performance. This study porosity, was permeability, led improvement It also found species woods increased at frequencies an air cavity between specimens tube’s wall increased.