A whoopee cushion is a practical joke device which produces a noise resembling a fart. It is made from two sheets of rubber that are glued together at the edges. There is a small opening with a flap at one end for air to enter and leave the cushion. To use it, one must first inflate it with air and then place it on a chair or squeeze it. If placed on a chair, an unsuspecting victim will sit on the whoopee cushion, forcing the air out of the opening, which causes the flap to vibrate and create the sound of flatulence.