Answer
Aortic valve insufficiency is heard during atrial diastole and ventricular diastole.
Mitral valve stenosis is heard during ventricular systole and from the middle of atrial diastole to atrial systole.
Work Step by Step
Aortic valve insufficiency is heard when the aortic valve does not close completely. The aortic valve closes in the middle of atrial diastole right before ventricular diastole begins, so the insufficiency would be heard after this point.
Mitral valve stenosis is heard when the mitral valve does not open completely. The mitral valve opens at the beginning of ventricular systole, so the stenosis would be heard throughout ventricular systole.