Urp… ’scuse me!
It does not sound like a burp and certainly not a physically or emotionally satisfying burp.
The only beings who burp that way are those seriously ill and can’t get the burp up and out of their bodies, but have it go off inside, because something is blocking the way like a large tumor, or because they are bloated with disease. It is frightfully awful.
It should be a nice, big, loud, foghorn beer burp that would shock someone unfamiliar with hobbits that they could produce that much of a burp.
Just go record someone really burping. That sounds like some industrial machine or something.

