Illustration of the eardrum, or tympanic membrane, seen from inside the ear. The eardrum separates the external ear from the middle ear. When sound impacts it, it vibrates and transmits that sound to the ear bones which in turn transmit the sound onwards to the inner ear. The white structure is part of the hammer (malleus), the first of the three small bones that connect the membrane to the inner ear. From Traite dAnatomie Humaine (1905) by French anatomist Leo Testut (1849-1925).