Sound waves in the ear canal vibrate Ear oSsicles is of rotation the ear drum oscillating the middle ear bones. Thus, the oscillations of the ear drum are conveyed to the oval window at the base of the cochlea tympanic Malleus Incus Stapes small force LARGE FORCE LARGE AMPLITUDE small amplitude Middle ear bones act an impedance matcher, enabling sound pressure waves in air to be introduced into the fluid-filled inner ear at the oval window. at the base of the cochlea Tympanic Round Base of stapes membrane window In oval windowSound waves in the ear canal vibrate the ear drum, oscillating the middle ear bones. Thus, the oscillations of the ear drum are conveyed to the oval window at the base of the cochlea Middle ear bones act an impedance matcher, enabling sound pressure waves in air to be introduced into the fluid-filled inner ear at the oval window, at the base of the cochlea