This is interesting as I just had a patient in a few weeks ago with the same complaint. Turns out that what he was hearing was his heart beat(pulse). This was due to an obstruction of his Eustachian tube. He would only hear the pulse sound in quiet or semi-quiet situations (like at home as opposed to work) and said he really noticed when he would lay down to sleep at night. When the Eustachian tube "clogs" and/or "swells" it put presses against one of the major arteries in neck which in turn then presses against the inner ear. This is why you then hear the pulsing noise.
Now to the remedy... we tried a combination of an allergy medication (Allegra or Zyrtec) and a nasal steroid. we did not find the winning combination until we changed the nasal steroid to Qnasl so that the pressure spray would push up into the sinus cavities and up the Eustachian tube. Once we did this, he problems were gone in four days. His wife was also ecstatic as she said his snoring decreased by 70%
Here it to great results as well!
You should consult a doctor about this. It could be anything from tinnitus, to an infection, to a heart problem.