This paper will summarize our knowledge of the propagation of sound in marine sediments. This knowledge is important to a wide range of acoustic problems, extending from the high‐frequency applications of detection of objects buried in the bottom sediment to the very low frequency application characterizing the propagation of acoustic energy over hundreds of kilometers. In these applications the ocean bottom becomes an important part of the acoustic waveguide. The desirable goal of a complete theoretical understanding of propagation has not been achieved. However, recent measurements of acoustic attenuation in the frequency range of a few hundred hertz are almost an order of magnitude smaller than have previously been measured, and these results may now permit progress in a more complete characterization of the acoustic properties of sediments. (The research performed on this topic by the author under the guidance of R. Reid was published in 1967 (“Acoustic Properties of Sediments,”J. Acoust. Soc. Am., 42, 882–890, 1967). This paper will briefly review aspects of that work and trace the progress in this area of research since that publi