Communication presented at the 17th International Congress on Acoustics, Rome, 2-7 September 2001.The absorption of sound in suspensions with particles much smaller than the acoustic wavelength is mainly due to the viscous drag between the fluid and the particles. In addition, viscous asymmetries generated in the flow field by the particles, partially entrained by the acoustic field, contribute to it. Such asymmetries, known as acoustic wakes, are considered in this work to derive the absorption coefficient based on the modification of the slip flow velocity. An experimental study is also presented where the value of the absorption coefficient is determined.Peer reviewed