耳塞

Also known as ear plug

alt=|thumb|upright=1.35|Pre-molded earplugs (left), formable earplugs (center), and roll-down foam earplugs (right) An earplug is a device that is inserted in the ear canal to protect the user's ears from loud noises, intrusion of water, foreign bodies, dust or excessive wind. Earplugs may be used as well to improve sleep quality or focus in noisy environments. Since they reduce the sound volume, earplugs may prevent hearing loss and tinnitus (ringing of the ears), in some cases.