A method for the preparation of a support area and for acoustic management: - on an aircraft turbomachine comprising an air inlet cone , and/or - on a nacelle of such a turbomachine comprising: -- at least one outer structure comprising at least one outer annular casing , and possibly: -- an inner structure comprising a fairing of a turbojet engine , which engine of a turbojet having an air inlet cone comprises a fan , the inner structure of the nacelle then defining, with the outer structure , an annular air vein for secondary air, and -- an exhaust nozzle comprising an outer primary nozzle sleeve and an inner primary nozzle tip defining between them an outlet channel for a primary air flow exciting the engine of the turbojet , in which method: - on at least said support area of the turbomachine or of the nacelle is reserved at least one recess recessed with respect to a surrounding general surface of said support defining a surface for contact with the moving air : -- in the turbomachine , on the air inlet cone , or -- on the nacelle , the recess being adapted to removably receive at least an acoustic panel and a non-acoustic panel , both having a surface for contact with the moving air , one in replacement of the other, - depending on an acoustic or an aerodynamic criterion, one said panel is removed from the recess in which said panel was contained and is replaced by a replacement panel adapted to replace it and which has a surface for contact with the moving air , said replacement panel being an acoustic panel if the panel removed is non-acoustic, and vice versa. - on an aircraft turbomachine comprising an air inlet cone , and/or - on a nacelle of such a turbomachine comprising: -- at least one outer structure comprising at least one outer annular casing , and possibly: -- an inner structure comprising a fairing of a turbojet engine , which engine of a turbojet having an air inlet cone comprises a fan , the inner structure of the nacelle then defining, with the outer structure , an annular air vein for secondary air, and -- an exhaust nozzle comprising an outer primary nozzle sleeve and an inner primary nozzle tip defining between them an outlet channel for a primary air flow exciting the engine of the turbojet , -- at least one outer structure comprising at least one outer annular casing , and possibly: -- an inner structure comprising a fairing of a turbojet engine , which engine of a turbojet having an air inlet cone comprises a fan , the inner structure of the nacelle then defining, with the outer structure , an annular air vein for secondary air, and -- an exhaust nozzle comprising an outer primary nozzle sleeve and an inner primary nozzle tip defining between them an outlet channel for a primary air flow exciting the engine of the turbojet , - on at least said support area of the turbomachine or of the nacelle is reserved at least one recess recessed with respect to a surrounding general surface of said support defining a surface for contact with the moving air : -- in the turbomachine , on the air inlet cone , or -- on the nacelle , the recess being adapted to removably receive at least an acoustic panel and a non-acoustic panel , both having a surface for contact with the moving air , one in replacement of the other, -- in the turbomachine , on the air inlet cone , or -- on the nacelle , - depending on an acoustic or an aerodynamic criterion, one said panel is removed from the recess in which said panel was contained and is replaced by a replacement panel adapted to replace it and which has a surface for contact with the moving air , said replacement panel being an acoustic panel if the panel removed is non-acoustic, and vice versa. <EOS>