If simultaneous shooting is carried out by incoherent source arrays, being the condition of blended acquisition, the deblending process generates shot records with a very low residual interference (blending noise). We found, theoretically and numerically, that deblended shot records had a better background-related signal-to-noise ratio than shot records in unblended surveys. This improvement increased with increasing blending fold and decreasing survey time. An interesting consequence of this property is that blended surveys can be carried out under more severe noise conditions than unblended surveys. It is advisable to optimize the survey time in areas with a large background noise level or in areas with severe environmental restrictions.