My dog used to stand over me making vomit noises until I woke up and fed her.

At first it was because she had an upset stomach when it had been too long since she'd eaten (like first thing in the morning). Then we swapped her to a better dog food, but by then she'd learned we'd feed her if she made those noises. We never tried to train get out of it because we appreciated that she was communicating her needs.