Okay, so...let's make this a specific hypothetical, and one that will sidestep the rights question:
Suppose I download my own novel,
From a Changeling Star, from Fictionwise. It's listed as having Read-Aloud disabled for all formats except .LIT. But suppose I chose another format like Mobipocket or eReader and I wanted to enable those to be read aloud. How would I do that? (Remember, I'm the copyright holder.)
I actually have no experience whatever with read-aloud software, so I don't even know if those particular formats are compatible even without the DRM.