hearing heart thumps in left ear much of time

In the last year, I've been hearing my heart thumping loudly in my left ear a lot of the time.  It is very regular and medium slow.  It is louder after exertion but can be present while sitting quietly.  I have quite severe hearing loss in the highs and wear hearing aids, but this occurs with or without the aids, and feels like it is in the bone.  Is this likely to be a heart or circulatory problem?  My GP just listened to my heart and thought it was a hearing problem, but that seems weird.

[ireneo]

I think it is associated with the ear. Yes, I have arrhythmias but my heart is fine. My left ear has had problems over the years. Sometimes it just hurts. Perhaps it's fluid in there that creates some kind of echo chamber. Even now I can hear/feel it thumping. I just know it's not a heart problem and it's not an ear infection. It just seems to be a byproduct of some past ear problems. Very odd.

[mizging]

I have a constant noise in my heart 24/7.  I was diagnosed as having too much carotid artery and what I hear is the blood rushing through the artery.  The diagnosing doctor said he would blow off his head if he had the problem.  My noise can be heard by others who place their ear to mine or by listening at any point on my head with a stethoscope.  The surgery to repair the problem is life-threatening where the condition is not.  I have just adopted the outlook that as long as I hear it, I'm still alive and kicking.

Ginger

[NYbirder]

Seems that both the responders and my doctor point to the ear here, and now I have further proof...it just completely went away about a week ago.  Even after running up several flights of stairs I cannot hear my heart thump.  My ears seemed clear but I have had occasional bits of stagger to the left, so maybe there was liquid there.  Anyway after about 8 months it is totally gone, which is a relief.  Thanks to the responders.