A muffled voice in chronic pharyngitis can be caused by incomplete closure of the vocal folds, inflammation involving the vocal cords, and gastroesophageal reflux. 1. Incomplete closure of the vocal folds: . Chronic pharyngitis causes the free edge of the vocal folds to hypertrophy and the ventricular band to hypertrophy will lead to the vocal fissure closure insufficiency, which will cause the symptoms of mute voice. 2. Inflammation involving the vocal folds: the spread of inflammation in chronic pharyngitis can lead to congestion and swelling of the vocal folds, thus affecting the amplitude of the vibration of the vocal folds, and the symptom of mute voice can occur. 3. Gastroesophageal reflux: If gastroesophageal reflux exists, the stomach contents reflux into the pharynx, irritating the mucous membrane of the larynx and causing the symptoms of hoarse voice. When the patient suffers from chronic pharyngitis and has symptoms of hoarseness, it is recommended to go to the hospital in time for examination and diagnosis, and under the guidance of the doctor to carry out the correct treatment.