The tympanic membrane is the membrane present in the outer structure of the ear which vibrates when it receives the sound vibrations from the outer world.
Inner to the tympanic brain lies three bones called incus, malleus and stapes. These bones are attached in a chain-like fashion convert the vibrations of the membrane to the mechanical vibrations of these bones.
Since the bone which fills the oval window and transfers the vibration to the inner ear is called stapes.
