Comparison between normalized dipole sound source from LES for the β = 20% sharp-edged (20–0.5–0–0) orifice at Re_o = 2.25 × 10⁴, the β = 11% upstream-chamfered (11–0.5–0.33–0) orifice at Re_o = 3 × 10⁴ and the β = 20% thin orifice (20–0.125–0–0) at Re_o = 2.25 × 10⁴. The LES source data is compared to measured source data for thin orifices with β = 9%, 16%, 25% by Gibert [2] and Moussou [17].