A voice belonging to a demonic entity that can be reproduced by humans with the proper placement of the locus of vibrations in one's throat. This is much easier for males than females. It's basically like talking in the front of your throat. You have to open your throat up, similar to when you frown really big and it tenses enough muscles in your neck to pull the skin on your chest up a little (and kind of like when you yawn). Your tongue will be pulled back a little, too. When you speak, the vibrations will be as low in your throat as you can make them. The other thing to remember is to not use too much air - too much airflow will make the voice sound high and harsh. Most men can get a nice, deep bass tone in their demonic voice. This is useful for playing the host body trick in crowded elevators.