Earwax

Earwax has a medical name, cerumen, and it is not stuck-on grime: it is closer to the grease that protects a leather boot. It is something the body makes on purpose. About 60% of its weight is keratin, the same tough protein found in skin, coming from shed skin cells; the rest is fats and small proteins called peptides.

Those fats and peptides are released by glands in the outer third of the ear canal, the little tube running from the outer ear to the eardrum. Some are sebaceous glands, the same ones that oil the skin; others are called ceruminous glands.

What cerumen does is take care of that skin: it keeps it moist, protects it from infection and works as a barrier against water, objects and insects getting in. And it usually comes out on its own: the simple movement of the jaw while chewing or talking carries it toward the opening.

That is why putting cotton swabs in usually backfires: it speeds up cerumen production and also pushes it deeper. When the wax becomes impacted, meaning packed in and stuck, it can block the canal and cause conductive hearing loss: you hear less because the sound cannot get through.