Displacement amplitudes of the acoustic wave propagating from the transition region into the corona, |𝒞₁|, relative to the transverse loop displacement at the loop top, ξ₀. Top panels: relative amplitude as a function of density contrast, ζ, for three values of transition region width, Δy, at a fixed period, P. Middle panels: relative amplitude as a function of Δy for three values of ζ at a fixed P. Bottom panels: relative amplitude as a function of P for three values of ζ at fixed Δy. The green dashed line shows the relative amplitude obtained from Eq. (24) from White & Verwichte (2021) for a fully reflective boundary. Vertical dashed and dotted lines represent values where the travel time from the lower boundary to y₀ are multiples of 4τ_S, ch/P, for the parameters of the black curve. The left and right sets of panels are for y₀ = 5 Mm and y₀ = 2Mm, respectively. Also, , which corresponds to a plasma-β = 0.1.