Syntetized voices

Hi, it could useful for a little choir where i sing to have their SATB parts sung aloud with the words that will be sing. I usually make four SATB parts where the voice of interest is played by a "church organ"and the other ones by a celestia.

I found a commercial service here:
http://www.choirservices.com/#!separate-voices/cq97

samples here:
http://www.choirservices.com/#!examples/c10qe

and something about a Microsoft project:
http://research.microsoft.com/en-us/projects/whistler/music.aspx

I know two (common) text to speech free programs,
http://dimio.altervista.org/eng/index.html ,
http://www.cross-plus-a.com/balabolka.htm .

I wonder if such a thing could be made for Musescore. Thanks,