Echo

Echo was a beautiful nymph who was quite talkative. One of her sisters was having an affair with Zeus, and the god's wife, Hera, grew suspicious. To protect her sister, she engaged Hera in a conversation to allow Zeus to get away. When Hera discovered, she grew furious and cursed Echo that she could only speak when repeating the words of those who spoke to her. Ashamed, she hid away in a cave, where her body eventually disappeared leaving only her voice...
The legend of Echo is one of my favorites. Like any myth, it's got a few versions.
Cave from ~anodyne-stock
Girl from ~A68Stock