Voice similarity

If you insert your wet hand into a wet cup, wiggling and moving your hand once it is inside, you’ll notice a certain similarity to a voice. With some practice you can make the cup “talk.” Your hand, or part of your hand, needs to nearly fill and cover the opening of the cup in order for this to work. Basically, your hand is like your tongue, and the cup is like your mouth and part of your throat.
– Ashley Walker