A muffled throat, i.e. hoarse voice, that has been present for 2 months indicates that it has not been effectively treated. Common causes include ear, nose and throat diseases, neurological disorders and so on. 1. Ear, nose and throat diseases are the most common causes of hoarseness, such as upper respiratory tract infections, vocal cord nodules, vocal polyps, laryngeal tuberculosis, as well as laryngeal contact ulcers and laryngeal cancer. 2. Neuropathy such as paralysis of superior laryngeal nerve or paralysis of recurrent laryngeal nerve can also cause hoarseness. 3. Lung cancer, thyroid tumors, skull base tumors and intracranial lesions and hysteria can also cause this symptom. If there is persistent hoarseness or recurring hoarseness, it is recommended to go to the hospital in time, improve the examination to clarify the cause of the disease and standardize the diagnosis and treatment.