The lattice Boltzmann method has been used to study the flow and associated sound generation in a flow pipe having a cavity close to the pipe's entry section. The study is an initial survey on the use of this method for such an aeroacoustic problem and does not represent a detailed parametric investigation. It is shown that vortices are formed by flow separation at the pipe's inflow end and that they interact with the cavity geometry. A basically reactive sound field is generated in the modeled geometry.