5. To listen to your friend's tummy, ask them to lift up or take off their shirt. Then hold the one funnel against their tummy and the other against your ear. You should hear a rumbling or gurgling noise. This sound comes from air, intestinal gas, digestive juices and smoshad-up food moving along the small intestine. The sound is louder if your friend has just eaten something or if he or she is hungry. Ask your friend to get a big glass of water or another drink. Then listen to his or her tummy again and ask him or her to flex his or her tummy in and out. You should hear a sloshing noise. This comes from the water being shaken up in your friend's tummy.