Sports-related head injury as a cause of ossicular trauma

Abstract

The middle ear is the part of the ear between the tympanic membrane and the oval window, and consists of three bones: the malleus, the incus and the stapes. The purpose of the auditory ossicles (or ossicular chain) is to transmit sound via a chain reaction of vibrations that connects the eardrum to the inner ear and cochlea. The auditory chain reaction starts when sound reaches the tympanic membrane. The vibrational pressure is passed to the malleus, an articulated bone that flexes at one of the two incudomalleolar joints. The vibration is then passed to the incus which flexes at another incudomalleolar joint before transferring the impulses to the stapes. The role of auditory ossicles is complete when the vibrational input is passed to the cochlea through the oval window. The auditory ossicles serve an important role in hearing in that they transition sound waves from the air to the fluid-filled core the cochlea. They effectively amp up the vibrations by around 30 decibels (dB) to accommodate this transition.1