Google Introduces Gemini 3.1 Flash TTS with Enhanced Speech and Control

Google has announced Gemini 3.1 Flash TTS, a new text-to-speech model focused on improving speech quality, expressive control, and multilingual generation. Unlike previous versions that prioritized simple conversion, this release emphasizes natural-language audio tags, support for over 70 languages, and native multi-speaker dialogue. This release signals a shift from 'black-box' audio generation to a more granular, instruction-based workflow.

One of the standout achievements of Gemini 3.1 Flash TTS is its performance on industry benchmarks. The model currently boasts an Elo score of 1,211 on the Artificial Analysis TTS leaderboard, making it Google's most natural and expressive speech model to date. Furthermore, the update introduces a more sophisticated control layer for AI developers. Instead of relying on static configurations, developers can now use audio tags and natural-language prompting to control style and tone, pacing, and accent of the speech.

A key differentiator for Gemini 3.1 Flash TTS is its support for native multi-speaker dialogue. Traditional TTS pipelines often require separate API calls for different voices, which can lead to disjointed pacing. By handling multiple speakers natively, the model maintains a more natural conversational flow, making it particularly useful for developers building podcasts, dramatic scripts, or collaborative assistant interfaces.

As generative audio reaches higher levels of fidelity, the ability to identify AI-generated content becomes a technical necessity. Google has integrated SynthID watermarking across all audio generated by Gemini 3.1 Flash TTS. The implementation of SynthID is designed with two priorities: imperceptibility and reliable detection. The watermark is embedded in a way that does not degrade the listener's audio experience and enables the identification of AI-generated content, assisting in preventing misinformation and ensuring transparency in digital ecosystems.

Overall, Gemini 3.1 Flash TTS represents a move toward a more 'authorial' approach to audio AI. By combining high benchmark performance with granular natural-language controls, the Google AI team is providing the tools to build voice experiences that feel less like synthesized output and more like directed performances.