I get this EXACT same thing. A sizzling/squishing sound in my throat/head when I’m hungry. I’ve always thought it was liquid of some sort making it’s way through a tight spot. I think I have thyroid issues and it may be due to that. Going to read on to see what other people say.
It's beyond me that this hasn't been solved yet. I believe the spinal fluid theory more. But still it's weird.
I experience this when I'm hungry. This morning before breakfast it happened every two minutes. Ate some eggs and it stopped.
Sounds just like a liquid with bubbles is draining into part of my spine right where it meets my skull at the back of my throat. As its draining the bubbles are popping like soda. It goes for about 3 seconds straight then stops.