ConcludedRan 10 daysin the edition since 16 Sep 20264 sourcesupdated 25 Sep 2026

Google DeepMind's Gemini 3.8 Flash TTS

The gist

Latest: Google DeepMind Launches Gemini 3.8 Flash TTS Voice Models

The models offer voice design from text prompts and voice cloning from short audio samples at low per-use cost. Built-in safety measures, including SynthID watermarking on all generated audio, are intended to keep AI-generated speech detectable.

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The full picture

Google DeepMind launched Gemini 3.8 Flash TTS and Gemini 3.8 Flash-Lite TTS on September 23, 2026, making both available through the Gemini API and Google AI Studio. Flash TTS supports generating new voices from text prompts, selecting from over 2,000 production-ready voices, or replicating a voice from a 30-second audio sample, with multilingual support across more than 100 languages. Flash-Lite TTS targets high-volume, cost-efficient use cases such as dubbing and voice agents. Google DeepMind stated that Flash TTS secured the #1 overall spot on Hume AI's Voice Design Benchmark with a score of 71.4, and both models took the top two spots on Hume AI's Overall Quality Index. Safety measures include consent verification for voice replication, SynthID watermarking on all generated audio, and C2PA credentials.

How it developed

25 September 2026

The Neuron reports Gemini 3.8 Live supports speech-to-speech interaction across 97 languages with simultaneous vision and audio input

24 September 2026added 25 Sep

The Neuron on September 24 corroborated Gemini 3.8 Flash TTS's core features, confirming promptable voice design, a library of over 2,000 stock voices, 30-second consented voice replication, and multilingual support across more than 100 languages.

Google DeepMind had released Flash TTS alongside Flash-Lite TTS, a companion model targeting high-volume applications such as dubbing and voice agents, through the Gemini API on September 23.

First citedThe Neuron

23 September 2026in the 24 Sep edition

Simon Willison published a hands-on playground on September 24 for Gemini 3.8 Flash TTS, the voice model Google DeepMind released the previous day through the Gemini API, reporting that generating 1 minute 18 seconds of audio took about 20 seconds and cost 2.74 cents.

The playground also demonstrated the API's multi-character conversation support, where each character can carry distinct voices and style instructions.

First citedDeepMind Blog Google DeepMind on X Simon Willison

Sources

DeepMind Blog