Educed impedances obtained for the wavenumbers evaluated for the PBE considering different velocities profile shapes with the impedance Z_SDOF at the lined wall. Velocities profiles match the universal wall law with u_τ = 3.95 ms⁻¹, in average Mach number and boundary layer displacement thickness δ^*. US – Upstream Source (downstream propagation), and; DS – Downstream Source (upstream propagation). (c) Plots the difference between the reactances and the reference reactance that are plotted in (b).