Heart Murmurs are abnormal sounds heard as a result of abnormal flow of blood through the heart. According to the Levine grading system the systolic murmurs can be graded as follows: Grade 1: Faint murmur that can be heard only when the few seconds have passed. Grade 2: Faint murmur that can be heard immediately. Grade 3: Murmur of moderate intensity. Grade 4: Loud murmur Grade 5: A loud murmur that can be easily heard when the edge of stethoscope is touching the skin. Grade 6: Loudest of all. This murmur can be heard even if the stethoscope is removed and is not touching the skin. For diastolic murmur 4 grades are used that includes: Grade 1: Barely audible. Grade 2: Audible, but soft. Grade 3: Easily audible. Grade 4: Loud.