In the framework of the EU funded project TC-STAR (Technology and Corpora for Speech to Speech Translation), research on TTS aims on providing a synthesized voice sounding like the source speaker speaking the target language. To progress in this direction, research is focused on naturalness, intelligibility, expressivity and voice conversion both, in the TC-STAR framework. For this purpose, specifications on large, high quality TTS databases have been developed and the data have been recorded for UK English, Spanish and Mandarin. The development of speech technology in TC-STAR is evaluation driven. Assessment of speech synthesis is needed to determine how well a system or technique performs in comparison to previous versions as well as other approaches (systems & methods). Apart from testing the whole system, all components of the system are evaluated separately. This approach grants better assessment of each component as well as identification of the best techniques in the different speech synthesis processes. This paper describes the specifications of Language Resources for speech synthesis and the specifications for evaluation of speech synthesis activities.