Comparison between PSD of measured pressures and estimated acoustic pressures for the β = 20% sharp-edged thick (20–0.5–0–0) orifice (left column) at Re_o = 2.25 × 10⁴, the β = 11% upstream-chamfered thick (11–0.5–0.33–0) orifice at Re_o = 3 × 10⁴ (center column) and the β = 20% sharp-edged thin (20–0.125–0–0) orifice at Re_o = 2.25 × 10⁴ (right column) at positions and 10. The acoustic pressures are estimated from LES and data from Gibert [2] and Moussou [17].