This　paper　presents　an　application　of　metal　foams　for　controlling　aerodynamic　noise　of　an　axial-flow　fan.　A　configuration　of　a　semi-open　cell　metal　foam　combined　with　a　backing　cavity　is　employed　to　attenuate　the　tonal　component　while　an　open-cell　metal　foam　is　used　to　absorb　the　broadband　component.　An　acoustic　impedance　model　is　employed　to　determine　the　optimal　geometrical　parameters　of　the　metal　foam　and　the　cavity.　Experimental　results　confirmed　that　the　tonal　noise　is　greatly　reduced　by　the　semi-open　cell　metal　foam　and　the　open　cell　metal　foam　shows　a　potential　of　absorbing　the　broadband　noise.　(C)　2017　Elsevier　Ltd.　All　rights　reserved.