2) Stick your chin a little and swallow air in such a posture as if to give a heavy yawn with almost no tension of the hypopharynx and the neck. When you have swallowed air, draw back the chin.
3) Take a big mouthful of air, contract the muscles of the cheeks and the pharynx, and first raising the tongue tip against the alveolar ridge and then rocking the rest of the tongue against the hard palate, try to move the air towards the pharynx.
4) The air swallowed soon goes down into the stomach. However, it is not your object to send air into the stomach (gastric airball), but to detain it in the esophagus and to use it to produce sounds. And not to let the air enter the stomach, you may apply a little strain to the abdomen and do as is described in section 2 ('How to expel air').
