Buzzing in the left ear and poor hearing are considered to be caused by sudden deafness, secretory otitis media and Meniere’s disease. 1. Sudden deafness: refers to the sudden, unexplained sensorineural hearing loss that occurs within 72 hours of the patient. In the case of low-frequency sudden deafness in the left ear, it can lead to hearing loss in the left ear, buzzing sound in the ear, hearing loss and other uncomfortable symptoms. 2. Secretory otitis media: It is a non-purulent inflammation of the middle ear mainly characterized by middle ear effusion, hearing loss, and intact tympanic membrane. It is related to Eustachian tube dysfunction, infection and immune response. Symptoms include ear pain, hearing loss, sensation of occlusion in the ear and buzzing tinnitus. 3. Ménière’s disease: It is a disease in which the lymphatic fluid in the inner ear or the ionic composition of the lymphatic fluid is disturbed, leading to episodes of vertigo, fluctuating deafness, tinnitus, and a feeling of tightness and swelling in the ear. If it occurs in the left ear, it can lead to a buzzing sound in the left ear and poor hearing. It is recommended that the cause of poor hearing and buzzing in the left ear be diagnosed and treated in a hospital.