I used to have an old VHS tape (can't find it anymore) that had a gentleman who grunted with his mouth. I know a lot of guys do this, often times letting out a little burp-like sound to stop a deer. This guy had a full repertoire of mouth/voice calls and tried to teach the viewers how he brings up the sound from the back of his throat. He said to try and say the word "weep" as you made the low burp noise from the back of your throat. It wasn't a real high budget production, but the guy could really make some neat grunts. Anyone recognize the video I'm referring to, or better yet know where to get a copy? Can't for the life of me remember the guys name.