Middle Ear

The Middle Ear refers to a collection of bones (ossicles) and muscles contained within a chamber (tympanic cavity) that sit between the Outer Ear and the Inner Ear, bounded by the tympanic membrane (eardrum) and the oval window respectively. The eardrum transforms air pressure waves into physical vibrations – the middle ear amplifies these vibrations – the oval window allows the amplified vibrations to “flow” into the fluid-filled cochlea. Therefore, the primary function of the middle ear is to act as a mechanical amplifier. Without the middle ear 99.9% of the sound energy entering the outer ear, and vibrating the eardrum, would be reflected by the fluid-filled inner ear. This is because fluid has a much higher impedance to sound waves than air, which in contrast is a very efficient medium.