Get a nice sensitive mic and head on down to Chipotle’s!
Seriously, that’s a tough one. My first instinct would be to search through my sound library, but you probably don’t have access to one. The most obvious way is to directly record a gurgling stomach. That happens all the time on VO sessions with sensitive mics. No need to starve for two days if you have a good sensitive mic. If you only have dynamics, well yeah, you’ll probably have to be groaning real hard to pick it up well. Then the Chipotle might start to actually be a serious idea. This would give you a realistic sound, which may not be what you want, in a comical setting for example.
If I had to design the sound, I’m not exactly sure how I’d go about doing it, but I have a vision of myself over a kitchen sink full of water with plastic bags and bottles. I’d try and record lots of different kinds of bubbles. I’d probably edit the best ones together and downpitch and EQ them.
It’s a proper sound design job, but I think it’d be worth it if the sound is important to your story. If it’s just a filler sound, maybe don’t spend too much time on it.
IHTH
JC Boulay
Technical Director
Audio Z
Montreal, Canada
http://www.audioz.com