The middle ear lies between the tympanic membrane and the inner ear. The middle ear space is filled with air and within it are the three smallest bones in our body, called the ossicles. These are known as the malleus (hammer), incus (anvil) and stapes (stirrup). The ossicles serve to mechanically amplify the pressure waves from the vibrating tympanic membrane to provide an efficient transfer of the sound energy into the fluid filled spaces of the inner ear.

In addition, the relative difference in the area of the tympanic membrane and the much smaller oval window lying beneath the stapes footplate allows for a concentration of the pressure wave much the way a spiked heel on a shoe concentrates force compared to a flat heel. These two mechanisms multiply the pressure wave at the tympanic membrane about 22 times.

Also in the middle ear is the opening of the Eustachian tube that allows for the equalization of air pressure on both side of the tympanic membrane. We all experience the opening and closing of the Eustachian tube when our ears pop going up or down in an elevator or airplane.