A geared turbofan engine, comprising: a first rotor; a fan connected to the first rotor, wherein the fan is capable of rotation at frequencies between 200 and 6000 Hz and has a fan pressure ratio of between 1.25 and 1.60; a second rotor; a gear train that connects the first rotor to the second rotor; a fan casing and a nacelle arranged circumferentially about a centerline and defining a bypass flow duct in which the fan is disposed; a plurality of discrete acoustic liner segments (38a, 38b, 38c, 38d, 38e, 38f) having varied geometric properties disposed along the bypass flow duct; wherein the plurality of discrete acoustic liner segments (38a - 38f) comprises a first acoustic liner segment, and a second acoustic liner segment, wherein each of the plurality of acoustic liner segments includes a cellular core structure, the cellular core structure comprising one or more resonator chambers having a width; wherein the cellular core structure of one of the plurality of discrete acoustic liner segments has a depth that differs from a depth of the cellular core structure of another of the plurality of discrete acoustic liner segments; and wherein the width of the one or more resonator chambers of the first acoustic liner segment differs from the width of the one or more resonator chambers of the second acoustic liner segment; and wherein the geared turbofan engine further comprises a core casing arranged circumferentially around the centerline within the nacelle and the fan casing and defining an inner surface of the bypass flow duct; and wherein at least one discrete acoustic liner segment (38a, 38b, 38c, 38f) of the plurality of discrete acoustic liner segments is disposed on the inner surface of the bypass flow duct; and wherein the first acoustic liner segment and the second acoustic liner segment are mounted on the outer surface of the bypass duct and form a portion of the rear section of the bypass duct, and wherein the first acoustic liner segment and the second acoustic liner segment have an abutting interface. a first rotor; a fan connected to the first rotor, wherein the fan is capable of rotation at frequencies between 200 and 6000 Hz and has a fan pressure ratio of between 1.25 and 1.60; a second rotor; a gear train that connects the first rotor to the second rotor; a fan casing and a nacelle arranged circumferentially about a centerline and defining a bypass flow duct in which the fan is disposed; a plurality of discrete acoustic liner segments (38a, 38b, 38c, 38d, 38e, 38f) having varied geometric properties disposed along the bypass flow duct; wherein the plurality of discrete acoustic liner segments (38a - 38f) comprises a first acoustic liner segment, and a second acoustic liner segment, wherein each of the plurality of acoustic liner segments includes a cellular core structure, the cellular core structure comprising one or more resonator chambers having a width; wherein the cellular core structure of one of the plurality of discrete acoustic liner segments has a depth that differs from a depth of the cellular core structure of another of the plurality of discrete acoustic liner segments; and wherein the width of the one or more resonator chambers of the first acoustic liner segment differs from the width of the one or more resonator chambers of the second acoustic liner segment; and wherein the geared turbofan engine further comprises a core casing arranged circumferentially around the centerline within the nacelle and the fan casing and defining an inner surface of the bypass flow duct; and wherein at least one discrete acoustic liner segment (38a, 38b, 38c, 38f) of the plurality of discrete acoustic liner segments is disposed on the inner surface of the bypass flow duct; and wherein the first acoustic liner segment and the second acoustic liner segment are mounted on the outer surface of the bypass duct and form a portion of the rear section of the bypass duct, and wherein the first acoustic liner segment and the second acoustic liner segment have an abutting interface.