Hearing loss in the left ear requires a visit to the hospital to examine the external ear canal and the condition of the eardrum, as well as electrical auscultation and acoustic impedance to find the cause of the appearance. In general, the causes of left ear drop are as follows: 1. Due to earwax or cerumen blockage in the external ear canal, you can find dark brown secretions blocked, hard and smelly in the external ear canal, which can be removed directly. If the cerumen is hard and cannot be removed, it can be soaked in sodium bicarbonate or sesame oil for three days and then sucked out to be cured. 2. Hearing loss due to repeated otitis media attacks. If there is fluid in the middle ear cavity or perforation of the tympanic membrane, the patient will need to have a CT scan of the mastoid process to rule out the possibility of hearing loss. Patients need to check the mastoid CT to rule out the presence of middle ear cholesteatoma or mastoiditis, and if both of these diseases are present, surgery is required to completely cure them. 3. Sudden deafness caused by ischemia, edema, and spasm of the ear nerve due to prolonged sleepless nights, fatigue, and stress can be clearly diagnosed by electrical audiometry and acoustic impedance. The treatment of sudden deafness requires nerve nutrition and vasodilatation therapy, along with hyperbaric oxygen chamber and local acupuncture. 4. Tumor lesions in the inner auditory canal or the ear, etc.