Some new technology.....

In 2002 Roger Ebert was diagnosed with thyroid cancer. After numerous surgeries on his throat, he eventually lost his ability to speak. With the new technology by CereProc Roger Ebert has recently gained his ability to speak once again. The only way Roger Ebert was able to gain his own voice back was through prior commentaries he made for several films on DVD. This presented a challenge because CereProc was trying to stitch together his voice from audio that was limited in length and poor in quality. Regardless of this challenge CereProc was able to create his voice which was recently debuted on Oprah as a success.
How it works….
They take the audio data that they carefully recorded and send it off for transcription and then segment it into very small pieces. The technique is similar to the one used by AT&T's NaturalVoices of selecting different pieces, or phonemes, of the audio and stitching them back together in clever ways. The trick is stitching them back together so they don't sound like they came from different context and different words.
CereProc creates and sells a variety of different voices with various accents, dialects, and personalities. People use CereProc's voices and text-to-speech software for many things like to learn English or other languages and some, like Roger Ebert, that have lost their own ability to speak. Some people want to capture a local dialect before it dies out. Some people use TTS software as a proofreading and editing tool to listen aloud to your own writing.
Sources: http://news.cnet.com/8301-11386_3-10463023-76.html?part=rss&&subj=news&&tag=2547-1_3-0-20