http://www.lhsl.com/realspeak/demo.cfm
"The technology is based on concatenation algorithms , where actual human voice segments are stored and used to convert text into speech. The basic units of the RealSpeak engine are not limited to diphones. The system uses a whole range of speech segments such as diphones, syllables, and also larger phoneme sequences. This mixture of voice segments and in-depth linguistic knowledge provides intelligent and human sounding pronunciation of variable text input."
Company background ("..developing language tools for commercially irrelevant languages like Hindi, Farsi and Turkish.")
"The technology is based on concatenation algorithms , where actual human voice segments are stored and used to convert text into speech. The basic units of the RealSpeak engine are not limited to diphones. The system uses a whole range of speech segments such as diphones, syllables, and also larger phoneme sequences. This mixture of voice segments and in-depth linguistic knowledge provides intelligent and human sounding pronunciation of variable text input."
Company background ("..developing language tools for commercially irrelevant languages like Hindi, Farsi and Turkish.")