The auditory tuberosity is the smallest bone in the body and consists of the hamate, anvil and stapes bones, which are interconnected within the superior tympanic chamber by means of ligaments and joints to form the chain of auditory bones. The stalk of the hammer bone is on the inner side of the tympanic membrane, between the mucosal and fibrous layers. The pedicle of the stapes is a circular ligament attached to the oval window, and the anvil is between the hammer bone and the stapes. The hammer bone, stirrup bone and anvil bone are interconnected by the anterior hammer ligament and the lateral ligament and are innervated by muscles. Its main function is to conduct sound waves to the inner ear, and it also has a strong effect of amplifying sound waves, which can amplify very subtle sounds more than ten times and can expand the hearing range.