Estimation of aerodynamic as well as hydrodynamic noise from an infinitely long circular cylinder subjected to low Reynolds number sub critical flow regime is detailed in this study. Large Eddy Simulations were performed on a smaller cylinder span length and correction factors were applied to account for the sound generated from longer span lengths. A comparison of spatial coherence lengths, which account for the sound correction factor in different fluid mediums is intended from the study. Computed aerodynamic noise favorably agrees with measured values and the same methodology was adopted for the estimation of hydrodynamic noise. © 2020 IEEE.