In the intact ear, sound energy in transmitted through the tympanic membrane and ossicular chain to the oval window. A very small fraction of the total energy reaches the round window by air conduction across the tympanic cavity and this in phase pressure is too weak to interfere significantly, the reciprocal pressure on the round window reaching it by the cochlear fluid and oval window route. Thus, the intact tympanic membrane protects the round window and feeds the ossicular chain and oval window. Current views state that the round window does not lie in the direct sound pathway to the cochlea but it functions as reliving point. Its mobility is as essential to normal hearing as that of any part of vibrating system. The malleus and incus vibrate as a combined unit rocking on a linear axis, which runs from the anterior ligament of the malleus to the attachment of the short process of the incus in the fossa incudis. When reciprocating movements of the conducting system take place, the mass of the malleus lying above this axis, serve to balance the mass of the drum head, malleus handle, long process of incus and stapes lying below it.