Thirty years of sand acoustics: A perspective on experiments, models and data/model comparisons

In the time period from 1981 to 2011 understanding of the acoustic behavior of sand matured via the combination of experiments, modeling and data/model comparisons. At the core of the issues addressed is the question of whether the sand is best described as a viscoelastic solid or a porous medium. Progress in answering this question has involved examining transmissioninto/ propagation-within/scattering-from sand. A perspective is presented that is based on the premise that results of experiments examining transmission/propagation/scattering must be explained in terms of one unified physical model of sand. The 30 year time span will be divided into three periods: 1981-1997, 1997-2004, and 2004-2011. Experiments, modeling and data/model comparisons from each of these periods will be used to arrive at a perspective on the acoustic behavior of sand.