Acoustic inspection is a reliable tool for assessing biological deterioration in wood. As wood decays, several mechanical properties are negatively affected. A variety of acoustic techniques have been developed to identify, and in some cases quantify, the extent to which the presence of decay has altered the wood. Knowledge of the extent of decay allows an inspector to estimate strength loss of the wood structure. This report serves as an introduction to acoustic inspection of biologically deteriorated wood. Basic acoustic techniques are described. Percentage reductions of wood mechanical properties as a function of wood mass reduction from decay are collected from references spanning nine decades. Common data analysis methods used in assessing acoustic data are presented. Finally, a model of wood material strength is given.
Senalik, C.A.; Ross, R.J.; Stokes, C.E.; França, T.S.F.A.; Shmulsky, R. 2022. Assessing biological deterioration in wood with acoustic-based techniques—a review. General Technical Report. FPL-GTR-291. Madison, WI: U.S. Department of Agriculture, Forest Service, Forest Products Laboratory. 12 p. https://doi.org/10.2737/FPL-GTR-291