Hearing Loss, Ear Health, and Lupus

How do we hear? Hearing is a surprisingly complicated process. First, sound starts as a vibration in the air. This vibration, which takes the form of a sound wave travels are caught by the outer ear. This ear is cupped to direct the sound wave into the narrow passageway in our head called the ear canal. The ear canal leads to the eardrum which is a membrane (thin layer of divider cells) that vibrates. At this point, the sound waves need to be amplified. This is performed by the three smallest bones in the body, named for the shapes they resemble: The malleus (or hammer) The incus (or anvil) The stapes (or stirrups) These amplifications travel to the cochlea, a snail-like, fluid-filled structure. Fluid carries sound and vibrations better than air. This fluid ripples along a membrane that runs through the whole organ, called the “basilar membrane.” Cells called “hair cells” are located on this membrane, and are named for the tiny hair-like cilia (officially called “sterocilia”) that react to these ripples. Much like whiskers, hair cells are attached to a neuron. When they react, they send neural impulses to the brain through a bundle of nerves called the “auditory nerve.” The brain processes these impulses into what we recognize as sound and puts the sound together with other sensory input and information to interpret sound. Quite the process!

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