Gemini 3.1 Flash TTS: the next generation of expressive AI speech

2026-04-15 · Source: The Keyword · Field: Technology & Digital — Artificial Intelligence & Machine Learning, Software Development & Engineering · Depth: Intermediate, medium

Summary

Google introduced Gemini 3.1 Flash TTS on April 15, 2026, a new text-to-speech (TTS) model designed for improved controllability, expressivity, and speech quality. This model supports over 70 languages and features "audio tags" that allow users to direct vocal style, pace, and delivery using natural language commands embedded in the text input. Gemini 3.1 Flash TTS achieved an Elo score of 1,211 on the Artificial Analysis TTS leaderboard, positioning it favorably for high-quality speech generation at a low cost. It also offers native multi-speaker dialogue and is rolling out in preview for developers via the Gemini API and Google AI Studio, for enterprises on Vertex AI, and for Workspace users through Google Vids. All audio generated by the model is watermarked with SynthID to aid in detecting AI-generated content.

Key takeaway

For NLP Engineers developing expressive AI speech applications, Gemini 3.1 Flash TTS offers enhanced control and quality. You should explore its audio tags in Google AI Studio to fine-tune vocal styles and pacing, ensuring consistent character voices and immersive audio experiences across your projects. The SynthID watermarking also provides a crucial layer for content authenticity.

Key insights

Gemini 3.1 Flash TTS offers granular control over AI speech through natural language audio tags and high-quality, cost-effective generation.

Principles

• Granular control enhances AI speech expressivity.
• Watermarking AI-generated audio aids in content provenance.

Method

Embed natural language audio tags directly into text input to control vocal style, pace, and delivery for AI speech output, then export parameters as Gemini API code.

In practice

• Use audio tags for scene direction and speaker-level specificity.
• Export perfected voice parameters for consistent use across projects.

Topics

• Gemini 3.1 Flash TTS
• Text-to-Speech Model
• Audio Tags
• AI Speech Generation
• SynthID Watermarking

Best for: Machine Learning Engineer, NLP Engineer, CTO, AI Engineer, Software Engineer, AI Product Manager

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Editorial summary, takeaway, and curation by AIssential. Original article published by The Keyword.