How to make English-language neural networks read in Russian

A Habr author published a material on how to make English-language neural networks for speech synthesis (TTS, Text-to-Speech) sound in Russian. The article opens with an acknowledgment that TTS technology is gradually displacing some of the work of professional voice actors and dubbing performers, and offers an overview of free models that require neither credits, nor subscriptions, nor bank card attachments — with the caveat that not all of them even support Russian language, and those that do often have a noticeable accent.

What exactly the author tested

At the center of the material — practical comparison: the author generates voice-overs for the same text in English and Russian using several free neural network models for speech synthesis, to assess how much the sound quality and pronunciation differ between languages. This approach answers a question rarely highlighted in marketing materials of the model developers themselves: how a model trained primarily on English corpus handles the phonetics and intonation of a language for which it was not originally designed.

Russian language is objectively more complex for speech synthesis than most Western European languages: free stress that can fall on different syllables in related words, a rich system of case endings affecting pronunciation, and an abundance of hissing and soft consonants require from the model a much more subtle phonetic model than, for example, English with its relatively predictable intonation. Most open TTS models are initially trained on English-language datasets simply because there is more such data in open access, and support for Russian is often added only in second place, less carefully.

What problems occur with English-language models for Russian

The key finding of the material — accent. The author compares the sound of some models to the pronunciation of Arnold Schwarzenegger in the film "Red Heat", where the actor plays a Soviet policeman with a recognizable, but clearly non-native Russian accent. This apt comparison reflects the typical problem of TTS models trained primarily on English speech: even when the model is formally able to pronounce Russian words, stresses, intonational contours and softness of consonant sounds are often transmitted incorrectly, because of which the result sounds recognizable but unnatural — like the speech of a foreigner, not a native speaker.

Key facts:

• The material compares free TTS models in English and Russian languages
• Selection condition for models — without credits, subscriptions and card attachment
• Not all tested models support Russian language
• Some of the models supporting Russian have a noticeable accent comparable to the pronunciation of Schwarzenegger's character in "Red Heat"

Should you use such models for Russian voice-over

The practical conclusion of the article concerns applicability: even if the model is free and overall impresses with English speech quality, for a Russian-language project — whether it's video voice-over, podcast or voice interface — you need to separately check how it handles Russian phonetics, not rely on the overall impression of English demos. The material essentially offers the reader a checklist for independent assessment: test the model on native text, compare pronunciation with real Russian speech and only then decide whether you can overlook language limitations for zero cost, or for a specific task you still need a paid model with explicit Russian support.

For authors who independently create content in Russian — bloggers, teachers, indie game developers — such comparative reviews are especially valuable precisely because they allow saving time on testing a dozen models manually and immediately move to those few that actually sound acceptable in Russian, without spending resources on models not originally intended for this. For many non-professional scenarios — rough voice-over, product test versions, personal projects — free English-language models may be a workable compromise, but for content aimed at a broad Russian-speaking audience, the accent the author describes will likely be unacceptable.