Speech Models

A complete reference for speech generation models in Qolaba — Gemini Flash TTS and Pro TTS, available voices, accent options, and best use cases.

Qolaba's Speech Generation is powered by Google's Gemini TTS — two models offering different trade-offs between speed, quality, and credit cost. Both models support single-speaker narration and multi-speaker dialogue generation with customizable voice, accent, and delivery style.

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Available Models

Model	Speed	Quality	Best For
Gemini Flash TTS	Fast	Good	Script drafting, quick iterations, testing voice and accent combinations
Gemini Pro TTS ⭐	Slightly slower	Higher — more expressive and natural	Final production output, client-ready audio, publishing

Test your script, voice selection, and accent configuration with Flash TTS first. Switch to Pro TTS for the final generation only. This approach saves credits without compromising final output quality.

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Model Capabilities

Both models share the same core capabilities:

Capability	Flash TTS	Pro TTS
Single Speaker Mode	✓	✓
Multi-Speaker Mode	✓	✓
Voice library	30+ voices	30+ voices
Accent & dialect selection	✓	✓
Style instructions	✓	✓
Multi-language support	✓	✓
Max script length	5,000 characters	5,000 characters

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Voice Library

Both models provide access to a library of 30+ distinct voice profiles. Each voice has a unique combination of tone, pitch, energy, and speaking style. Click any voice in the interface to hear a preview before selecting.

Available Voices

Voice	Character
Zephyr	Bright, clear, and energetic
Puck	Upbeat and playful
Charon	Informative and measured
Kore	Firm and confident
Fenrir	Excitable and expressive
Aoede	Smooth and warm
Leda	Youthful and approachable
Orus	Clear and neutral
Schedar	Gravelly and deep
Gacrux	Soft and gentle
Pulcherrima	Calm and composed
Achird	Conversational and natural
Zubenelgenubi	Professional and authoritative
Vindemiatrix	Storytelling and expressive
Sadachbia	Warm and personable
Sadaltager	Crisp and articulate
Sulafat	Rich and resonant

The full voice library is accessible directly in the Speech Generation workspace. Click any voice name to preview it before selecting.

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Accent & Dialect Support

The output language is determined automatically by the language of your input script — write in any language and the audio is generated in that language. Accent selection refines pronunciation for languages with multiple regional dialects.

Available Accents by Language

Language	Available Dialects
English	United States, United Kingdom, India, Australia
French	France, Canada
Spanish	Spain, Latin America
Arabic	Egypt, Global
Mandarin	China, Taiwan
Hindi	India
Portuguese	Brazil, Portugal
German	Germany, Austria
Japanese	Japan
Korean	Korea

The output language always follows the language of your input text. Accent selection narrows the regional dialect within that language — it does not override the language itself.

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Style Instructions

Both models support style instructions — a plain-language description of the desired delivery tone and manner entered in the Style Prompt field.

Examples:

Intent	Style Instruction
Warm and conversational	"Speak warmly and conversationally, like talking to a friend"
Professional narration	"Clear, professional, and authoritative tone"
Energetic marketing	"Enthusiastic and high-energy delivery"
Calm instructional	"Calm, slow-paced, and easy to follow"
Storytelling	"Engaging narrative style with natural pauses and expression"

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Flash TTS vs. Pro TTS — When to Use Each

Use Flash TTS when:

• Testing a new script for the first time

• Validating voice, accent, and style combinations before final generation

• Producing audio for internal use, drafts, or non-published content

• Working at high volume where credit efficiency matters

Use Pro TTS when:

• Generating final production audio for publishing

• Delivering client-ready voiceovers, ads, or podcast content

• The naturalness and expressiveness of the voice matters for the audience

• Multi-speaker dialogue needs to sound as realistic as possible