Naomi Houston is a 16-year-old ballerina, one of the main dancers in this year's Black Nativity, the story of the birth of Christ in gospel, playing at the Paladium this weekend. As the white wings are handed out, a fellow dancer comes up to her and points to a hot pink hearing aide nestled in her ear. "Where's the purple one?" asks the friend. Naomi is almost completely deaf. She wears hearing aides in both ears but the purple one died two weeks ago. It doesn't matter. Sometimes she prefers not to hear the music at all.