The ear is made up of three parts: the external, middle, and inner ear. Together, these structures help process air vibrations as sound, and this helps us enjoy our favourite music, as well as alert us of potential threats. Now, while the inner ear also plays a role in balance, the main role of the external and middle ear is to transfer and amplify sound to the inner ear with the help of the three smallest bones in the body: the auditory ossicles.

Let’s start with the external ear, which is by far the most common anatomical spot to hang earrings from. The external ear is actually a complex structure made of the auricle, also called the pinna; and the external acoustic meatus.

Now, let’s take a closer look at the auricle, which is the part of the external ear that surrounds the opening of the external acoustic meatus, and funnels soundwaves towards the external acoustic meatus. It is made of irregularly shaped cartilage covered with skin. The elevated outer rim of the auricle is the helix. The smaller elevated rim parallel to the helix is called the antihelix. The depression in the middle of the auricle is called the concha. Right next to the concha, there’s the opening of the external acoustic meatus. Inferior to the concha, there’s the lobule of the auricle. And finally, anterior to the opening, there’s an elevation called the tragus.

The next part of the external ear is the external acoustic meatus, which is an S-shaped canal that extends from the concha, through the temporal bone, to the tympanic membrane. The entire canal is covered with skin, and is divided into a lateral third, made of cartilage, and a medial two-thirds, made of bone.

Now, at the end of the external acoustic meatus, there’s the thin, oval tympanic membrane, more commonly known as the eardrum, which separates the external ear from the middle ear. When sound waves hit the tympanic membrane, it vibrates and transfers the vibration to the three auditory ossicles of the middle ear. If you take a look through an otoscope, you will notice the tympanic membrane is concave externally, with the center of the concavity called the umbo. One of the ossicles, called the malleus, attaches to the internal surface of the tympanic membrane.