An earplug is a small piece of soft material you push gently into your ear canal to block out noise or protect your ears. Most earplugs are made of foam, silicone, or wax, and they work by creating a seal that muffles sound before it reaches your eardrum.

People use earplugs in many situations. Construction workers wear them to protect their hearing from loud machinery. Students use them to create quiet while studying in noisy places. Light sleepers wear earplugs at night to block out snoring or street noise. Musicians and concertgoers use special earplugs that reduce volume without distorting the music. Swimmers use waterproof earplugs to keep water out of their ears.

The most common earplugs are made of foam that you squeeze into a small cylinder, insert into your ear, and then let expand to fill the ear canal. Other types stay soft and can be reused many times. Some earplugs are connected by a cord so you don't lose one.

While earplugs are useful, you shouldn't wear them when you need to hear important sounds, like a smoke alarm at night or a teacher's instructions during class. And never push them in too far or use dirty earplugs, since that could hurt your ears or cause an infection.