In "New Kindle Audio Feature Causes a Stir," Paul Aiken, Executive Director of the Authors Guild, said about the new Kindle's read-aloud feature: "They don't have the right to read a book out loud. That's an audio right, which is derivative under copyright law."
In reaction, John Herrman at Gizmodo said ("Authors Guild Claims Kindle 2 Text-to-Speech Somehow Violates Copyright"): "the idea that a robotic reading of text is materially equivalent to a proper, recorded audio version of a book—read by the author in many cases—is ridiculous."
Mike Masnick at Techdirt said ("According To Author's Guild, You Cannot Read Books Out Loud"):
By that reasoning pretty much any use of text-to-speech software is illegal, which would make for a fascinating legal case. And, actually, if you take that reasoning further, any reading out loud from a book that is not yours is also a violation of copyright law, according to Aitken. Read to your kids at night? Watch out for the Authors Guild police banging down your door.