Echo was a nymph who could only repeat others' last words. Only her voice is left.
Echo was a nymph cursed by the goddess Hera so she could only repeat the last words others said. She faded away until only her voice was left, bouncing off the rocks.
Yell into Palo Duro Canyon and Echo answers back.
An 'echo chamber' is a team that only repeats itself. Invite people who disagree.
Practice it in Skepsis