So, did Audrey Hepburn sing in My Fair Lady? Kind of, not really, and only if you listen very carefully. But did she perform Eliza? Absolutely. She lived that role with every bone in her body. If you watch the film today, your brain will still tell you “that’s Audrey’s voice” because the image is so powerful it rewrites reality.
So next time someone smugly corrects you at a dinner party, you can nod and say, “Actually, she recorded the whole thing—and you can hear it online. But yes, Marni Nixon was the official voice.” Then take a bite of your brownie and smile. You now own this piece of trivia. Use it wisely.