I have had this issue off and on for a couple of years now. Most of the time I can feel/hear the blood going through the veins in the back of my neck and head when I am laying down. Today it is my feet while I sit. It squeaks to the pulse, kind of like when someone walks across a squeaky spot in the floor. It seems random when it happens. I'm curious if anyone else has experienced this, or have any idea what it is?