Been having this happen for the past year and a half. Always happens to me when I'm laying down, or if my neck is in a certain position and when my stomach growls. So glad I'm not alone, maybe we can all solve this mystery together.
For my medical history, I haven't had any surgeries or any illness/ diseases. I sometimes get stars in my vision. And autoimmune diseases run in my family along with high cholesterol , high blood pressure and diabetes. So far my blood test come out normal and just started talking to a doctor about my family history. I also might have sleep apnea due to my large tonsils. Also large tonsils itself can affect other things, I mentioned to her that sometimes my neck gets tense when I wake up and she said it might be due to my body having to struggle to take a breath because of my tonsils.
But I'm thinking on how this relates to the liquid noise, maybe it could be the pressure on your neck due to weight gain or large tonsils. I'm saying this because I have large tonsils and just about 2 years ago also gained weight over covid, about 30 pounds from usual weight.