Sound absorption by wood in relation to anatomical and mechanical properties

The results of basic research on sound absorption by transverse and longitudinal sections of four Egyptian woods are presented. The amount of sound absorption was determined by laboratory experiments with wood samples in a standing wave apparatus. The specific gravity, maximum crushing strength and hardness of tested samples were also determined in order to study the relationship between wood absorption of sound and its mechanical properties. Cross-sections of the wood samples were also microscopically tested. The results are discussed in terms of two basic mechanisms of sound absorption—the flow resistance and mechanical hysterisis. The results show that sound absorption measurements have potential both as a non-destructive test and for the evaluation of the mechanical properties of woods.