Many of our friends are confused by ear diseases, but I believe that most of them are not too sure about the structure of the ear, after all, we can only see the auricle from the outside. Our ears are divided into three parts, from the outer ear to the inner ear, the outer ear, the middle ear and the inner ear in that order (see figure below). The middle ear is like a drum, an air-containing cavity, and the outermost side is the eardrum. The most important structures in the middle ear cavity are the three auditory tuberosities, the hamate, anvil and stapes, in that order. The hammer bone is attached to the tympanic membrane, and when sound from the outside world is transmitted in, it drives the vibration of the three auditory bones in turn to transmit the sound to the inner ear. The middle ear is connected to the nasopharynx through the eustachian tube, which is the only channel of communication between the middle ear and the outside world under normal circumstances, and is also the most important channel for otitis media infection. The inner ear is divided into two parts. The snail-like part called the cochlea is responsible for converting sound in the form of vibrations into electrical signals, which are then transmitted through the auditory nerve to the brain, where hearing is produced. The other part is called the vestibule and is responsible for balance.