Plain English Meaning
Soft pieces you push into your ears to block out loud noise so your hearing isn't damaged and so you can concentrate.
Full Definition
Small inserts placed in the outer ear canal to reduce the level of sound reaching the eardrum, used in aviation training environments to protect hearing from prolonged exposure to engine, propeller, and cockpit noise.
Context Anchor
Seen in discussions of cockpit noise, ramp noise, fatigue, and protecting hearing during flight training.
Why Pilots Care
Unprotected exposure to aircraft noise can cause permanent hearing loss, reducing the ability to hear critical radio calls and cockpit alerts over time.