The Acoustics of Liquid Foams

Beside other transport properties of liquid foams, like the optical or electrical ones, the acoustics of liquid foams reveals a great complexity and non-trivial features. Here we present a review of recent experimental and theoretical results on how a sound wave interacts with either a macroscopic foam sample or with its isolated building blocks (films and Plateau borders). The analysis of the literature allows us to determine what is now well understood, what could be measured in foams by acoustics, and what are the remaining issues and perspectives in this research field.