gdam can be used with the freely-available festival speech generation package, which was made at the University of Edinburgh.
First install festival and a voice or two from either packages or source code from the link above.
Then copy the text2wave script from the example directory onto your path. Make sure it is marked as executable, using chmod +x. For my debian system, the following suffices:
% zcat /usr/share/doc/festival/examples/text2wave.gz $gt; /usr/local/bin/text2wave % chmod +x /usr/local/bin/text2wave |
You'll also need to install one or more of the voices. As of writing, package names for festival voices include:
festvox-kallpc16k
festvox-kallpc8k
festvox-kdlpc16k
festvox-rablpc16k
When you run gdam-launcher just specify --define festival.