If your voice has been muffled for a month and is still not good, you may not have standardized treatment for the cause of the problem. Muffled voice may be caused by vocal polyps, papillomas of the vocal cords, malignant tumors of the vocal cords, etc., which need to be treated for the cause of the problem. 1. Vocal polyps: due to poor voice habits, dietary habits and other reasons, resulting in polyps on the vocal cords will also appear hoarse. The diagnosis of vocal polyps should be surgically removed, depending on the size and location of the polyp to determine the specific surgical method. Commonly used methods are local anesthesia fiber (electronic) nasopharyngolaryngoscopic resection, general anesthesia microscopic support laryngoscopic resection. 2. Vocal cord papilloma: excessive proliferation of local epithelial tissues in the vocal cord induces papilloma, which manifests as hoarseness, accompanied by symptoms such as dry pharynx, itchy pharynx, foreign body sensation, swallowing and breathing discomfort, etc. Surgery is usually required. Surgery is usually needed to remove the tumor with laryngeal forceps under direct laryngoscopy or indirect laryngoscopy; or physical therapy, laser, cryotherapy, and so on. 3. Malignant tumor of vocal folds: malignant tumor of vocal folds usually manifests as hoarseness in early stage, which needs to be treated with surgery and radiotherapy according to specific conditions. If your voice has been mute for a month, it may be caused by improper vocalization, laryngitis, etc. It is recommended that you consult a doctor as soon as possible for a detailed examination to identify the cause of the disease and follow the doctor’s instructions for treatment.