Hearing issue

I have been experiencing a systolic turbulence sound in my left ear before I am fully asleep. It sounds like a periodic subtle or mild rushing or whooshing pulsation along with a very faint heartbeat. I do not notice this when I am active and upright but only while waiting to fall asleep. Has anyone had these symptoms and/or been treated for it?

Several months ago, I had developed a fluid buildup in the same ear behind the eardrum which caused me to lose the hearing in that ear. It was due to an airborne allergy. I was advised by a nurse to take Sudafed and Afrin for three days. I did, it cleared up and my hearing was restored. No similar problem since until this the last few weeks.
Go back to the ear doctor and get checked out again. Don't take chances ... it is your ears for Christ sakes. Sounds like fluid build up. Have you tried sleeping either on a wedge type pillow or propped up. This would allow for drainage or at least, may impede fluid flowing.

I burst both my eardrums, at different times, 20 years ago. It literally took years to get better.

Nothing is quick in the ear healing world.

The next time it happens, try equalizing. Thats when you pinch your nose while at the same time trying to exhale through your nose. Simply put, it makes your ears pop. Doing that may give you some clues as to what is going on. Another thing you can try is to clean your ears. If you're careful you can get right up to your ear drum with a Q-Tip. I do it every day and it keeps my ears very clean. Last time I went to the ear doctor for a cleaning, they couldn't do anything because there was no build up to remove.
My PCP tells his patience to not use q-tips. He prefers you flush them out while taking a shower than jamming a q-tip in your ear.

Take Rar1's advice and head back to the doctor.
To the doctor you must go, and do it quickly.
My ENT does not recommend neither water flushing nor Q-tips. I block my ears from swimming pool or any swimming water with custom ear plugs perfectly fit to my shell(paid just $39 cash to audiologist for fitting and manufacturing) during my periodical aquatic training and do same during showers. He recommends to keep ears as dry as possible so that wax built-up will peel off on its own. Less moisture in your ears will speed up wax fall off.
There are vacuum cleaners for ears, but should be used with caution not to damage your ear drums.

Fluid build-up is definite call to go back to your ENT specialist again.
Regarding Zd542's suggestion about daily q-tip cleaning, I found this to be a bad idea. I did the very same thing for years on end. I now produce almost no ear wax as a result. Problem is, my ears itch most of the time do to excessive dryness. I am tired of tired of trying to scratch my inner ear with my index finger. We are all anal audiophiles. Daily cleaning is not the way to go. Your particular issue may be a precursor for tinnitus. I agree with others that a ENT doctor visit is a good idea. Don't cheap out on your ears.They're the only pair you have.
Irrigation(with an ear cleaning kit) rather than Q tips is the recommend method for property and safely cleaning the ear canal. I'd also suggest a visit to see an ENT physician for a thorough evaluation.
I have used an ear wax softener on two alternate days this weekend. In between I irrigated with a bulb syringe and some luke warn water. This seemed to lessen the turbulence noise but not completely eliminate it.

Today I took Zd542's advice regarding equalizing pressure. This has eliminated the muffled sound of my own voice. I will not know if it did anything for the circulation sound until I retire for the night.

I do have sinus and allergy issues. The Great Smoky Mountain region where I reside is the airborne antigen capital of the U.S. If you Google this problem the causes are many from minor to very serious. I have a Dr. appointment scheduled for next week.
I wouldn't do the equalization thing without consulting your doctor first.
Ear wax removal kits contain an ear wax softner and a bulb syringe for iirigation,this is safe and effective.
It's likely your respiratory system around your middle ears and sinuses,. etc. I can experience similar pusatile sensations deep in my ears during and after heavy activity in hot weather with allergies acting up. It's worse leaning forward and laying on my side.

The nearby arterial heartbeat pressure sounds may increase if your middle ears have excess fluid pressure that's not draining through your eustachian tubes. You may need to port those sub's with a decongestant after a medical exam ! Squish, squish squish...hope your much better soon.
As the fluid builds up around your ears it can amplify the sound of your heartbeat. You can get the same results from inverting yourself so even a subtle buildup of pressure while trying to sleep can make your heartbeat all the more noticeable and annoying.

I had an ear infection that led to a bursting of my inner ear drum which leaked the infection onto my pillow (eech!) The infection came on late one afternoon at work so I went to the doctor who thought I was high on something because my equilibrium was off which made me very shaky. It wasn't until the doctor took a look in my ear that she put me on antibiotics (oral and eardrops) but it was too late. Right before the bursting of the eardrum there was that rushing sound you spoke of that sounded like a jet was taking off and then boom, leaking ear.

It had no lasting effect but it's something I wouldn't want to go through again so take the advice given here and use that ear wax removal kit regularly and good luck on your doctors visit.

All the best,