For a few minutes after I woke up this morning, I had the ability to hear blood rushing past the workings within my left ear, not as the usual abstract ringing noise, but as a real sound of fluid moving under pressure. I guess I didn't think this was possible, and found it surprising and interesting. It sounded just like wind, and would recede whenever I willed myself to stillness. This is the closest thing to pure-informational biofeedback I've ever experienced. Very odd.
It faded after a little while, but now I see that it's a rather windy day today...