If a quiet but immediately audible murmur is heard, how would this murmur be graded?

A murmur that is described as "quiet but immediately audible" falls into a specific grading scale used in auscultation of heart sounds. The grading system for cardiac murmurs ranges from Grade I to Grade VI, where each grade describes the intensity and audibility of the murmur.

Grade I murmurs are barely audible, while Grade II murmurs are quiet but still immediately audible upon careful auscultation. This means that Grade II murmurs can be heard with minimal effort but are not loud enough to be mistaken for a more prominent sound.

Thus, a murmur that is quiet yet readily audible perfectly aligns with the characteristics of a Grade II classification. It reflects a murmur that does not require strenuous listening but is distinct enough to be identified right away. Hence, this is why the assigned grade is accurate in this situation.