My mother has it and I have it but only in one ear, I can only sleep on one my left side as if I sleep on right side I get pulse in my ear which apparently is diagnosed as tinnitus, I worked in a very high noise environment for over 35 years , not sure if that was reason or it’s hereditary, it use to bother me not any more guess I’m just use to it plus I no longer sleep on my right side simple really lol
,The condition where you can hear your pulse is called Pulsatile Tinnitus. There can be some underlying health conditions for it - have you mentioned it to your doctor?