ThonburianTTS vs OmniVoice vs ElevenLabs: Which Thai TTS Sounds Most Human?

In the quest to determine which Thai text-to-speech (TTS) system produces the most human-like audio, three contenders have emerged as the most notable: ThonburianTTS, OmniVoice, and ElevenLabs. These models differ in their origins, language coverage, voice cloning capabilities, cost, and ease of use.

ThonburianTTS, developed by a Thai research team, leverages the F5-TTS architecture and flow matching techniques to generate speech. Its primary strengths lie in pronunciation accuracy and robustness against messy text formatting, a crucial factor given Thai's unique spacing rules. Furthermore, ThonburianTTS excels in voice cloning from short audio clips, and it has even undergone peer-review at the iSAI-NLP 2025 conference held in Phuket.

OmniVoice, created by the k2-fsa team, boasts the widest language coverage, supporting over 600 languages. This allows for zero-shot voice cloning, meaning it can replicate a voice from a brief audio sample without the need for retraining. In practice, Thai users have found that OmniVoice produces clearer audio compared to general multilingual models. Additionally, OmniVoice's multi-language support enables users to create content in various languages without switching between tools.

ElevenLabs, a commercial service, is renowned for its high-quality audio and straightforward workflow. However, it lacks a native Thai voice, as the model primarily relies on training data from other languages. ElevenLabs shines in its comprehensive system, which includes project management, script splitting, and fine-grained controls, features that are typically lacking in open-source models.

When comparing the three, several key factors come into play. First, the quality of the output is directly tied to the clarity of the reference audio used. Poor or noisy reference audio will result in a similarly subpar cloned voice. Second, cloning someone else's voice raises legal and ethical concerns, so using one's own voice is generally acceptable, while using another person's voice requires explicit consent, and regulations vary across jurisdictions.

Third, open-source models require installation and configuration, which may be challenging for users without experience in running models locally. In contrast, commercial services offer a more convenient, immediate solution, albeit at a cost.

For those who require regular Thai audio narration, investing time to learn ThonburianTTS could prove beneficial in the long run. However, if the need for Thai TTS is occasional, utilizing an existing service like OmniVoice might save time and resources. Ultimately, the choice between these three TTS models depends on the specific needs and circumstances of the user.