A hard bag inside the cochlea may be caused by the following reasons: 1. Boils in the external auditory canal, also known as limited otitis externa, are mainly purulent infections that occur after bacterial infections invade the cartilage of the external auditory canal, and clinical anti-inflammatory treatment is required. Osteoma of the external ear canal, which mainly occurs in the bone of the external ear canal, has no obvious symptoms in the early stage, but when the osteoma gradually increases and blocks the ear cavity, it will lead to stuffy feeling in the ear or hearing loss, etc. In such cases, surgery to remove the osteoma can be considered.