The stapes is a stirrup-shaped bone located in the inner ear. It is one of three bones known as ‘auditory ossicles.’ The other two auditory ossicle bones are the malleus and incus.

The purpose of the stapes and auditory ossicles is to change and amplify sound vibrations into mechanical impulses that travel to the brain via the auditory nerve fibers.

The stapes transmit sound waves to the inner ear fluid. It changes sounds into mechanical vibrations transmitted through the oval window. Vibrations move across perilymph fluid in the cochlea, where hair cells are moved by waves and stimulate the auditory nerve fibers.

Sound waves cause the stirrup-shaped stapes to vibrate. The stapes transmit vibrations through its footplate, which rests on the oval window. Thus sound is transmitted to the inner ear fluid via perilymph and converted into electrical impulses sent to the brain by cochlear nerve fibers.

The auditory pathway begins with the outer ear, which collects sound waves. The wave passes through the ear canal and vibrates the eardrum (tympanic membrane).

The auditory ossicles (malleus, incus, and stapes) are located in the middle ear. They collect sound vibrations from the tympanic membrane and change them into mechanical vibrations.

If a person has an infection in the upper respiratory tract, it can be transmitted to the auditory ossicles. The upper respiratory tract includes the nose, sinuses, throat, and mouthparts.

Mastoiditis is an infection of the bone surrounding the ear canal called the mastoid process. If this infection spreads through the temporal bone (in which stapes is located), it can cause inflammation and conductive hearing loss.

There is no known way to prevent mastoiditis from affecting the stapes. A doctor may prescribe antibiotics before any symptoms appear to reduce or stop the infection. If left untreated, an individual may lose their hearing permanently due to a conductive hearing loss.