I imagine that stomach acids would probably be quite different, but whenever I'd get battery acid on my hands by accident, it would feel like a burning rash after a certain point which would make me realize I'd need to wash it off.
Being digested would be like that but far worse. I'm not into endo, but that thought makes me imagine a more fantasy type of digestion, where it strips you of your energy and numbs you a bit beforehand. rashes and burns have been some of my least favorite ways of getting hurt. Very uncomfortable.
With the soundscape, I'd imagine it'd be like when you lie your head on somebody's tummy after they've eaten and you can hear the digestion, but like you're wearing a headset instead of the muteness to hearing audio from someone else wearing one.