Why do I hear and feel this sizzling twirling sound from my head when I lay down?

When I'm laying down, I always hear something sizzling inside my head. I dont know if its from my head or from my ears. I've had this for over a year now and I am a little concerned. Dr said dont worry about it. It hears like something is sizzling or swirling or bubbling or a crackling sound inside my head. and this occurs when I'm laying down, mostly when I lay my head against the pillow. ALso, everytime my tummy growls, I feel the sizzling feeling around my head. This doesnt hurt but it gets annoying. What could this sound and feeling be? Should I be concerend? Have anyone heard of this before?Seems like this sizzling feeling starts on my necks and travels up my head. would this be nerve irration or blood clots? or, could this be muscle or joint problem? I know my neck is stiff and my sholders hurt and its also stiff many times.