Google has added prompt-based voice remixing to Gemini 3.8 Flash text-to-speech, letting users change how generated speech sounds through Google AI Studio and the Gemini API. Users can prompt changes to a voice's timbre, pitch, pace and accent. The feature is part of Gemini 3.8 Flash, which became generally available in September 2026. Gemini 3.8 is Google's flagship text-to-speech offering.