Re: Already paid.
But that's the thing. Even if it did prevent a "second sale", it's a *second sale*. The original sale already had the content. This is format shifting, not "copying".
It's no more "copying" than a TV being analog tube vs playing on a Digital LCD "copies" the VHS from tape to silicon.
The spoken words, already contain the entire text, but the automation (or even non-automation) would have transcribed that back to text.
It would be akin to suing someone over putting visual descriptions of a movie on a DVD... the DVD already has the visuals included and paid for, so transcribing "there is a mountain with a woman singing "over the hills"" breaks no copywrite!