The speech synth is based on rsynth by the late
Nick Ing-Simmons (et al).
He described the legal status as:
This is a text to speech system produced by
integrating various pieces of code and tables
of data, which are all (I believe) in the
public domain.
Since then, the rsynth source code has passed legal
checks by several open source organizations, so it
"should" be pretty safe.
The primary copyright claims seem to have to do
with text-to-speech dictionary use, which I've
removed completely.
I've done some serious refactoring, clean-up and
feature removal on the source, as all I need is
"a" free, simple speech synth, not a "good"
speech synth. Since I've removed a bunch of stuff,
this is probably safer public domain release
than the original.
(I'm rather surprised there's no good public domain
speech synths out there; after all, it's 2013..)
I'm placing my changes in public domain as well,
or if that's not acceptable for you, then CC0:
http://creativecommons.org/publicdomain/zero/1.0/
The SoLoud interface files (soloud_speech.*) are
under ZLib/LibPNG license.
-- Jari Komppa
2013