The structure in the human ear that converts sound vibrations into mechanical vibrations of the oval window is the chain of

Sound waves vibrate the eardrum, which moves the three small bones of the middle ear: malleus, incus and stapes. These amplify and pass the vibration to the oval window of the cochlea. The hair cells then change the vibrations in the fluid into nerve impulses, the semicircular canals help balance, and the Eustachian tube equalises pressure with the throat.