Construction of the acoustic inventory for a Greek text-to-speech concatenative synthesis system

The development of the Greek text-to-speech (TTS) system by NTUA is based on the method of concatenative synthesis and follows the Bell Labs approach to this technique. Concatenative synthesis is one of the simplest methods for speech synthesis and at the same time bypasses most of the problems encountered by articulatory and formant synthesis techniques. The method relies on designing and creating the acoustic inventory of the language by taking real recorded speech, cutting it into segments and concatenating these segments back together during synthesis. The design and implementation of the acoustic database is a key factor for the performance of the synthesizer, since all the possible phone-to-phone transitions must be considered in order to minimize abrupt discontinuities and thus maximize the naturalness of the synthesized utterances.