The organs of hearing are the ears, which are composed of three parts: the outer ear, the middle ear, and the inner ear. The outer ear is made up of the pinna, which is the visible part of the ear, and the ear canal, which leads to the eardrum. The middle ear contains three small bones called ossicles, which transmit sound vibrations from the eardrum to the inner ear. The inner ear is a complex structure that contains the cochlea, which is responsible for converting sound vibrations into nerve signals that are sent to the brain.