Lever ratio of tympanic membrane is:

Lever-Action of OssiclesHandle of malleus is 1.3 times longer than process of the incus which constitutes for the lever-action.Area Ratio:The area ratio of tympanic membrane is 14:1Lever ratio = 1.3: 1= Their product is 18:1 i.e. the pressure exeed at oval window.This helps in the transformer action of the middle ear (impedance matching mechanism) i.e. conveing sound of greater amplitude and less force to that of lesser amplitude but greater force.