Osteogenesis imperfecta

The ear serves as the organ responsible for both hearing and balance. It is composed of three primary parts (Figure 1):

• Outer ear: This includes the earlobe or auricle and the external auditory canal.
• Middle ear: Separated from the outer ear by the eardrum or tympanum, the middle ear comprises a cavity that houses the ossicles (malleus, incus, and stapes). The Eustachian tube, which connects to the throat, exits from this cavity and functions to equalise the pressure on both sides of the eardrum, maintaining the same pressure as the surrounding environment.
• Inner ear: The inner ear consists of the cochlea, a spiral-shaped structure resembling a snail, which connects to the auditory nerve responsible for transmitting signals to the brain. Additionally, the inner ear encompasses the vestibule and the semicircular canals, which play a crucial role in maintaining balance.

In order to hear naturally, each of these components must function properly. But how does hearing occur? To understand the process of hearing, we need to grasp the concept of sound. When sound is produced, invisible vibrations travel through the air as sound waves, representing changes in sound pressure. The auricle collects these waves, which then travel through the external auditory canal and strike the eardrum, causing it to vibrate in response to the incoming sound pressure. The vibrations are then transmitted through the three ear ossicles, exerting pressure on the fluids within the inner ear in a selective manner based on the received sound. Within the inner ear, these vibrations are converted into electrical impulses, which are then transmitted through the auditory nerve to the brain. It is the brain that interprets these impulses, enabling us to perceive them as sounds or language. The quality and clarity of the captured sound waves and their transmission to the brain depend on the proper functioning of our ears.