earplug

A piece of protective gear meant to be inserted in the ear canal to protect the wearer's hearing from loud noises or the intrusion of water.

To fit with earplugs.

In this same strain of mouse, earplugging from 17-22 days postpartum is effective in inducing susceptibility to audiogenic seizures...

There wasn't much I could tell him, earplugged, but I crawled into turbine number 3 and waved him on in.