why can't he hear it?

I have been consulting cardiologists for more than 20 years for rheumatic mitral stenosis, and aortic regurgitation.  I have always been told that I have four murmurs with the murmur of MS being graded III/VI,(I've been told it is textbook, and the doctors always get med students in to hear it. The cardiologist caring for me now (almost one year), says he cannot hear the MS murmur, but I know from experience he is listening in the wrong place. He is one of the most reknowned in his field, and I don't want to tell him how to do his job, but I think it is a little strange.  He has only listened to my heart twice in the twelve times I 've been there.
Should I let it go?

[Cleveland Clinic, MD]

Murmurs can change in intensity and the degree of intensity of the murmur does not correlate with the severity of the valvular problem.  Does it make a difference to your overall care? Probably not.  As long as you are otherwise getting good follow-up and care I wouldn't go doctor shopping yet.