Calypso is kindhearted, and caring, yet could be feisty and rebellious, not liking the fact that she had to fall in love simply because the gods wanted her to as a punishment. She was very shy around visitors to her island as anyone that arrives there is someone she would fall in love with, causing her to hide her true feelings. She also has a warm heart, telling Percy that even if her father is a Titan, she still loves him and has no anger toward the gods for trapping her on her island. She shows a level of curiosity to Percy, asking him about how the world has changed in the time she has been trapped and feels bad that there is a place where flowers cannot grow (New York City). She is also very down to earth. (Yes I got this off of wikipedia, don't judge me.) I don't have any specific voice in mind, so, go nuts!