Hollywood beauty Charlize Theron refuses to lip sync when she begins filming a biopic of 1960s singer DUSTY SPRINGFIELD. The MONSTER Oscar-winner wants to follow the example set by Walk the Line co-stars Reese Witherspoon and Joaquin Phoenix by recording her own versions of the British legend's classic songs. She says, "It's important to sing myself. She had an amazing voice but I am trying to make my own voice spot on."