If a patient’s hearing in the left ear is not as good as the right ear, it often means that the hearing in the left ear has decreased. First, it is usually due to neurological changes in the left ear, such as staying up late and not resting well, or working in a particularly noisy environment. Second, there is inflammation in the middle ear cavity, which is considered to be due to an upper respiratory tract infection. Thirdly, there is cerumen in the ear canal, and a large amount of cerumen blockage will cause the patient’s hearing in the left ear to be inferior to that in the right ear. The actual hearing loss must be further examined in the hospital to clarify the specific cause before further treatment. The patient must pay attention to the protection of the ear in life, to avoid hearing loss affect normal life.