Two-year-old baby suddenly mute voice may be related to emotional excitement, laryngitis. 1. emotional excitement: two-year-old baby vocal cords are not yet mature, when the baby emotional excitement, such as excited shouting, loud crying, etc., can cause vocal fatigue, there will be swelling and inflammation, manifested as a mute voice. 2. Laryngitis: acute diffuse inflammation of the mucous membrane of the larynx caused by bacterial and viral infections, laryngoscopy can see the larynx, vocal cords with varying degrees of congestion, edema, manifested as barking cough, hoarseness, laryngeal ringing, inspiratory dyspnea, etc., heavier at night after sleep, such as laryngeal obstruction can result in asphyxiation and death. Two-year-old baby suddenly mute voice may also have other reasons, it is recommended to go to the hospital in a timely manner, improve the examination to clarify the cause of the disease, give targeted treatment or treatment.