The sputum sound is aggravated after the baby has done nebulization, there may be different situations as follows: 1. It is related to the baby’s primary disease. In the process of doing nebulization inhalation in babies, there is discharge of secretions, which are excreted into the throat or secreted into the trachea, and the sound of sputum chirping appears. It is mainly excreted into the throat, which is the effect of the primary disease. 2. When doing nebulization, the nebulized water droplets and droplets are distributed in the parts of the throat and trachea. Children’s airways are relatively small, and these nebulized plus some phlegm from the primary disease may even form a kind of phlegm filament adhering to the top of the trachea or pharyngeal wall, and even both sides can adhere together and be connected together by mucus filaments, and these can also produce phlegm sound.