Hearing heartbeat in left ear when laying and changing position. short periods of muffled hearing in same ear. daily headaches in back of head.

Likely noncaddiac: Normal heart beats can frequently be heard by patients when they lie on their side or ear. It's a common complaint i hear in the office. We title it "cardiac awareness". Uncertain why it manifests itself to patients when it does. I suspect this is not a cardiac abnormality. Headaches obviously shouldn't be treated lightly. Common allergies on up to more important organic causes may be responsible.