In the contemporary world of techniques, voice technologies, such as speech recognition, synthesis of speech signals, and their combined versions, acquire more and more significance. If we had a good synthesizer, we could use it widely. An example could be the reading of electronic books in voice, etc. Speech synthesizers of an older generation were quite primitive. A modern synthesis machine is not only able to read the text evenly, but to convey the emotionality as well. Speech synthesizer can raise a tone, dictate a question, and synthesize a voice of a desired timbre and speed. These features considerably enrich the speech synthesized. The aim of the research paper is to analyze the operation principles of the present speech signal synthesizers and to select the type of synthesis according to the quality indicators; prior to the compilation of Lithuanian sound set, to analyze the basics of phonetics. The features of phonemes and diphones are examined in the paper. The final result of the work is the sound set of Lithuanian language incorporating the phonemes and diphones. Synthesizer of Lithuanian language may be developed using this sound set. To implement this work, the program PRAAT was used. This software was selected due to its flexibility in the acoustic analysis of speech signals. The paper includes: 1. The analysis of general functional diagram of speech synthesis by text as well as the principles of concatenate synthesis. 2. Compilation and analysis of the... [to full text]