Published Outdoor Speech Synthesis System Rhvoice 1.2.4 , originally developed to ensure high-quality support for the Russian language, but then adapted for other languages, including English, Portuguese, Ukrainian, Kyrgyz, Tatar and Georgian. The code is written in C ++ and extends under the LGPL 2.1 license. Supported work in GNU / Linux , Windows and android . The program is compatible with typical TTS interfaces (text-to-speed) to convert text to speech: SAPI5 (Windows), Speech Dispatcher ( GNU / Linux) and Android Text-to-Speech API, but also can be used in the on-screen reader NVDA .
The program uses parametric The synthesis method with statistical models ( statistical Parametric Synthesis on the basis of HMM – Hidden Markov Model). The advantage of the statistical model is low overhead and inconspicuration to CPU power. All operations are executed locally on the user system. Three levels of speech quality are supported (the lower the quality – the higher the performance and less reaction time).
Configured the setting and change of votes. For Russian language Available 9 vote options , for English – 5. Votes are formed on The basis of the records of natural speech. Due to the use of a statistical model, the quality of pronunciation does not reach the level of synthesizers generating speech based on a combination of natural speech fragments, but nevertheless the result is completely picky and reminds the broadcast of recording from the loudspeaker.
In the settings, you can change the speed, height and volume. To change the tempo, the library Sonic can be applied. It is possible to automatically define and switch the language based on the analysis of the input text (for example, for words and quotes in another language, the synthesis model for this language can be used). Voice profiles are supported that determine the combinations of votes for different languages.