If the six-month-old baby’s voice is mute, we should consider whether it is caused by serious crying, if it is caused by crying, you can try to do a good job of soothing the child, reduce crying, often can be quickly improved. Another common cause is acute laryngitis, in addition to hoarseness, the baby will often appear barking cough, in this case must pay attention to the baby there is no laryngeal obstruction, because the anatomical characteristics of infants is the laryngeal cavity is narrower, the vocal folds are narrow, and the sound is mainly by the vibration of the vocal cords, hoarseness of the vocal cords will be oedema, but also laryngeal stenosis, which can easily lead to inspiratory respiratory distress. Acute laryngitis is an emergency situation for infants and requires immediate hospitalization. Many patients are treated with antibiotics which can be combined with nebulized inhalation therapy.