Diphones vs. Triphones in Czech unit selection TTS

Abstract

When we started to deal with the unit selection technique in ARTIC TTS, the question of the choice of the unit type used within the system was being dealt with. Although the basic version of our TTS system is based on triphones, we decided on the use of diphones in unit selection - mainly due to our concerns about the susceptibility of the unit selection technique to segmentation inaccuracies, and due to a limited experience with the overall system behaviour. However, we also planned to examine the possibilities of the use of triphones. As the first version of our unit selection is being built at present, this paper will examine whether the use of diphones can bring a significant advantage over the use of triphones, and whether there is a clear reason why one type of units behaves better than the other. © Springer-Verlag Berlin Heidelberg 2006.