Introducing porosity onto an aerofoil has been shown to have a significant influence on the boundary layer and provide significant reductions in its noise radiation. This proposal describes a multi-disciplinary research project aimed at understanding and exploiting the interactions between porous aerofoils and the boundary layers developing over them for the purpose of optimising noise reductions without compromising aerodynamic performance. The use of adaptive manufacturing technology will be investigated for providing the optimum porosity at different operating conditions.