A fan section for use in a gas turbine engine comprising: a fan rotor having a plurality of fan blades; a plurality of exit guide vanes positioned to be downstream of said fan rotor, said fan rotor being driven through a gear reduction; characterised in that: a first ratio of a number of exit guide vanes to a number of fan blades is between about.8 and about 2.5; said exit guide vanes are provided with both optimized sweep and optimized lean to provide an acoustic feature; wherein optimized sweep means that an outer periphery of said exit guide vanes is positioned to be downstream of a location of an inner periphery of said fan exit guide vane, and a sweep angle is between about 5 degrees and about 35 degrees; and wherein optimized lean means that an outer periphery of said fan exit guide vane is positioned at a greater circumferential distance than an inner periphery of said fan exit guide vane in a direction of rotation of said fan, and wherein a lean angle is between about 2 degrees and about 15 degrees; wherein said exit guide vanes have a hollow opening, said hollow opening being covered by an acoustic liner having a face sheet, wherein said face sheet has a thickness (t), and a diameter of holes in said face sheet is selected to be less than or equal to about.3 of the thickness (t) and wherein holes in the face sheet result in at least about 5% of a surface area of the material. a fan rotor having a plurality of fan blades; a plurality of exit guide vanes positioned to be downstream of said fan rotor, said fan rotor being driven through a gear reduction; characterised in that: a first ratio of a number of exit guide vanes to a number of fan blades is between about.8 and about 2.5; said exit guide vanes are provided with both optimized sweep and optimized lean to provide an acoustic feature; wherein optimized sweep means that an outer periphery of said exit guide vanes is positioned to be downstream of a location of an inner periphery of said fan exit guide vane, and a sweep angle is between about 5 degrees and about 35 degrees; and wherein optimized lean means that an outer periphery of said fan exit guide vane is positioned at a greater circumferential distance than an inner periphery of said fan exit guide vane in a direction of rotation of said fan, and wherein a lean angle is between about 2 degrees and about 15 degrees; wherein said exit guide vanes have a hollow opening, said hollow opening being covered by an acoustic liner having a face sheet, wherein said face sheet has a thickness (t), and a diameter of holes in said face sheet is selected to be less than or equal to about.3 of the thickness (t) and wherein holes in the face sheet result in at least about 5% of a surface area of the material. a first ratio of a number of exit guide vanes to a number of fan blades is between about.8 and about 2.5; said exit guide vanes are provided with both optimized sweep and optimized lean to provide an acoustic feature; wherein optimized sweep means that an outer periphery of said exit guide vanes is positioned to be downstream of a location of an inner periphery of said fan exit guide vane, and a sweep angle is between about 5 degrees and about 35 degrees; and wherein optimized lean means that an outer periphery of said fan exit guide vane is positioned at a greater circumferential distance than an inner periphery of said fan exit guide vane in a direction of rotation of said fan, and wherein a lean angle is between about 2 degrees and about 15 degrees; wherein said exit guide vanes have a hollow opening, said hollow opening being covered by an acoustic liner having a face sheet, wherein said face sheet has a thickness (t), and a diameter of holes in said face sheet is selected to be less than or equal to about.3 of the thickness (t) and wherein holes in the face sheet result in at least about 5% of a surface area of the material.