Ive been reading the audiobook of March Roach’s Stiff, and, coincidentally, she just covered this. The answer is an unequivocal “yes”.
Aren’t you glad you know this?
I’ve read that corpses can ‘breathe’ after death. The term used in the article was ‘agonal breathing’, but I looked that up and it’s not the right term. If I understood it right, the body would continue to release air through the mouth for some time after death, and that could be mistaken for breathing.
But if the sphincter is totally relaxed, why would gas escaping produce a sound?
Gah I have been angry at that factoid about every corpse shitting itself on death so damn long, only if there was already feces waiting to be expelled in the rectum!
I guess it would depend on resonance. Even a relaxed sphincter will have some elasticity and therefore resonance; even wood resonates under the right conditions.
I didn’t cite the South Park episode to be a fact or factoid; just for humor.