Yes I have,but I get no answer.

Hi George-
I was wondering if a spirit ever calls us up and gets a wrong number. Seems unlikely. However, considering your prior recollections, I wonder if you might still be hearing warning bells.

Most of us sleep in a state in which our inwards directed attention is filled by a ringing, hissing, and buzzing that is the noise of the brain thinking. Then we stop attending to this as we wake. Occasionally people get tinnitis that bothers them, but they forget about it when they concentrate on listening to something else.  This is normal. When it won't turn off, usually it has a cause.

I wonder whether you hear a continual ringing, a variation in the ringing, or an intermittent on and off ringing.

A steady noise that never changes would suggest an inner ear event - perhaps injury from excessive rap music that has bruised one of the auditory cilia in the cochlear structure, or occasionally a minor fungal infection etc could do it.

Anything that varies at other than the rate of your pulse suggests that there's something else going on, and is somehow external to your physical state, rooted in either your own psyche or the outside world as it connects to you.

Going to sleep I wonder whether you could trace the sound back to an image of what actually is ringing - either a complete situational image, or maybe just an outline of the object itself.

Sounds interesting-
d