The ear is made of flexible, soft tissue that attaches to the side of the head. It’s divided into three parts called the outer, middle, and inner ear. Each part has an important function in the hearing process.
The outer ear consists of skin and cartilage, called the auricle, and the ear canal. The eardrum, or tympanic membrane, is a thin membrane that separates the outer ear from the middle ear.
The middle ear is an air-filled chamber containing three small bones called ossicles. They connect the eardrum to the inner ear and are named the malleus (or hammer), incus (or anvil), and stapes (or stirrup). Normal hearing occurs when the sound waves pass though the ear canal and vibrate the eardrum.
The air chamber in the middle ear connects to the back of the nose via the Eustachian tube. In both ears, the Eustachian tube serves as a pressure-equalizing valve and drains any fluid that collects in the middle ear into the back of the throat.
The final part of the ear is called the inner ear. It contains a structure called the cochlea, which sends signals to the brain that enable hearing. The cochlea is shaped much like a snail’s shell and has small hair cells, called “cilia,” that are bathed in fluid. These cilia send signals from the inner ear to the area of the brain that helps maintain balance when walking or sitting upright.