This woman in my cl makes loud fart noises but isn't really farting. What causes that?

Noise is generally caused by vibrations, all noise that is. This may be from air bubbles trapped in folds of skin that are escaping, or even from just simply putting your lips on your arm firmly, then exhaling firmly. All in all, a fart noise can come from a variety of things. I have even experienced my armpits making fart noises without using my hands.