SPEAKER (GOVOREC): A Complete Slovenian Text-to Speech System

Abstract

While text-to-speech (TTS) systems for major world languages are quite advanced, smaller languages, like our Slovenian language, lack quality TTS synthesis. At the “Jožef Stefan” Institute a system called SPEAKER (GOVOREC) has been developed. It is capable of automatic conversion of any Slovenian text into speech. The different phases of the synthesis task are performed by several sequentially operating independent modules: text analysis, prosody generation and segmental concatenation. The first module is comprised of text normalization and grapheme-to-phoneme conversion tasks. In order to generate rules for our synthesis scheme, data were collected by analysing the readings of ten speakers, five males and five females. A two-level approach has been used for duration modeling, and a so-called superpositional approach for pitch modeling. A speech waveform is synthesized using unit selection-based methods and a concatenative TD-PSOLA or HNM+ technique. The system was first implemented in the EMA employment agent, which provides information about available jobs in Slovenia and is now used by members of the Slovenian Foundation for the Blind and Vision-Impaired. Then, it was given free of charge to all people with disabilities. The system was awarded with the first prize for innovation in the field of life improvements for people with disabilities (given by the Government Office for the Disabled and Chronically Sick of the Republic of Slovenia). SPEAKER is freely accessible for non-commercial purposes through the Internet. Currently, several leading Slovenian telecommunication companies are testing the system for providing information (e-mail, short messaging service—SMS, weather reports, traffic information) through mobile phones.