In sequence, sound waves pass from the outer ear to the middle ear, and then to the inner ear. The outer ear consists of the visible portion on the side of the head, known as the pinna, and the external auditory canal (ear canal). The purpose of the pinna is to catch sound waves, amplify them slightly, and funnel them down the ear canal to the tympanic membrane (eardrum). The tympanic membrane is a very thin structure that separates the outer ear canal from the middle ear space. The middle ear is an air-filled cavity that sits between the tympanic membrane and the inner ear. The middle ear also consists of three tiny bones called ossicles, the malleus, incus, and stapes. These bones transfer sound vibrations from the eardrum to the inner ear. The inner ear is just beyond the middle ear, in a small hole in the temporal bones that help make up the sides of your skull. The inner ear contains the cochlea, vestibular nerve, and semicircular canals. In the inner ear, the sound waves are converted into electrical energy, which your hearing nerve delivers to your brain as sound, making it possible for you to hear.