Examples from the Web for earplug
"This is like a dream," her voice murmured in Blades' earplug.
Michael Blades was outside, overseeing the installation of a receptor, when his earplug buzzed.
So then Makann did all the talking; they couldn't even depend on him to parrot what they were giving him with an earplug phone.Space Viking|Henry Beam Piper
Now he got a Megabuck unit, put the earplug into place, and tried again.The Pirates of Shan|Harold Leland Goodwin