The aerodynamic noise generated by a circular cylinder in uniform flow represents a central topic in many engineering and environmental applications, such as high-speed train pantographs, landing gear systems, etc. In recent years, it has been proven that coating a circular cylinder with a porous medium represents an effective noise mitigation. However, the precise mechanism through which this suppression performance is achieved is not clear yet. In the most common view according to the Curle’s analogy, the aerodynamic noise generated by a cylinder in uniform flow can be modelled, in equivalent terms, by a surface distribution of dipolar sources associated with pressure fluctuations acting on the cylinder surface and by volumetric sources located in the wake, linked to the unsteady velocity fluctuations.