Amazon Kindle 2's text-to-speech feature, which reads electronic books aloud, is sparking more heated words. Amazon, if you recall, said it would allow authors and publishers to switch off text-to-speech on book titles, after the Authors Guild raised copyright concerns. The National Federation of the Blind and other disability groups called on Amazon to fully retain text-to-speech, saying it gives the visually impaired equal access to electronic books. Now, amid reports that publishing giant Random House is now turning off the read-aloud feature on its Kindle titles, the disability groups are cranking up the pressure again.

Here's a statement from Marc Maurer, president of the National Federation of the Blind:

When Random House turned off the text-to-speech function on all of its e-books for the Kindle 2, it turned off access to this service for more than 15 million print-disabled Americans. The blind and other print-disabled readers have the right to purchase e-books using this service with text-to-speech enabled. Blocking text-to-speech prohibits access for print-disabled readers and is both reprehensible and discriminatory. We urge President Obama, whose e-books are now being blocked from over 15 million Americans, to either demand that access be restored or to move to a publisher who does not engage in discrimination.

A spokeswoman for Random House couldn't immediately be reached for comment.

Maurer was apparently referring to the Kindle editions of President Obama's autobiographical works, "Dreams from My Father" and "The Audacity of Hope," which list Crown, a division of Random House, as their publisher.

The Authors Guild has argued that Kindle 2's read-aloud feature threatens to eat into the lucrative market for audio books without duly compensating copyright holders.