noun

Your eardrum is a thin piece of skin inside your ear that helps you hear. It vibrates when sound waves come into your ear, and it sends those vibrations to your brain so you can hear.

Example

1. The eardrum is a thin membrane that separates the outer ear from the middle ear.
2. A doctor can diagnose ear infections by examining the eardrum with an otoscope.
3. When sound waves travel through the ear canal, they vibrate the eardrum and cause it to move.