✔ 最佳答案
This phenomenon is caused by jerkiness of the diaphragm muscles. When you are inhaling, the diaphragm muscles will contract while the diaphragm will be flattened. If will want to solve this problem, we better let the diaphragm muscles relax. When you are exhaling, the diaphragm muscles will relax while the diaphragm will return to its dome shape. As a result, take a deep breathe and then exhailing very slowly can help relaxing the diaphragm muscles.