In reply to Hat Dude:
Yes, I mentioned that in the December film thread. Possibly a bit unfair to denigrate Wood's singing, but not as unfair as not telling her they weren't going to use her voice in the final version.
I quite like Hepburn's voice and am very glad she was allowed to sing Moon River in stead of being overdubbed. Your reference to My Fair Lady prompted me to seek out the Hepburn version and it definitely has a charm of its own, but then I found a clip of her doing I Could Have Danced All Night and she is struggling a bit there.
Post edited at 13:22