Voice Design

Overview

Voice design generates unique voices based on natural language descriptions. Describe the voice you want, and Izwi creates it:

• No samples needed — Create voices from scratch
• Infinite variety — Design any voice you can describe
• Quick iteration — Rapidly test different voice concepts
• Creative freedom — Perfect for characters and personas

Getting Started

Download a Voice Design Model

izwi pull qwen3-tts-0.6b-voicedesign

Design a Voice

Describe the voice you want:

A warm, friendly female voice with a slight British accent. Middle-aged, professional but approachable.

Using the Web UI

Step 1: Describe Your Voice

1. Navigate to Voice Design in the sidebar
2. Enter a description of your desired voice
3. Be specific about characteristics you want

Step 2: Generate Sample

1. Enter sample text to hear the voice
2. Click Generate
3. Listen to the result

Step 3: Iterate

• Adjust your description
• Generate again
• Repeat until satisfied

Voice Description Tips

Effective Descriptions

Include details about:

Example Descriptions

News anchor:

A professional male voice, mid-30s, with a clear American accent. Authoritative and trustworthy, with measured pacing.

Children's narrator:

A warm, enthusiastic female voice. Friendly and expressive, perfect for storytelling. Slightly higher pitch with playful energy.

AI assistant:

A calm, neutral voice with no strong accent. Clear and helpful, not robotic but not overly emotional. Professional and efficient.

Audiobook narrator:

A rich, deep male voice with a slight British accent. Mature and sophisticated, with excellent diction and a storytelling quality.

Using the CLI

Generate with Voice Description

izwi tts "Hello, this is my designed voice" \ --model qwen3-tts-0.6b-voicedesign \ --speaker "A warm, friendly female voice with a British accent" \ --output designed.wav

Using the API

Endpoint

POST /v1/audio/speech

Request

{
  "model": "qwen3-tts-0.6b-voicedesign",
  "input": "Hello, this is my designed voice.",
  "voice_description": "A warm, friendly female voice with a British accent"
}

Example (curl)

curl -X POST http://localhost:8080/v1/audio/speech \ -H "Content-Type: application/json" \ -d '{ "model": "qwen3-tts-0.6b-voicedesign", "input": "Hello, this is my designed voice.", "voice_description": "A warm, friendly female voice" }' \ --output designed.wav

Available Models

Larger models better interpret complex descriptions.

Best Practices

Be Specific

❌ "A nice voice"

✅ "A warm, professional female voice in her 40s with a calm, reassuring tone"

Use Comparisons

"Similar to a podcast host — conversational but polished"

Describe the Context

"A voice suitable for meditation apps — slow, soothing, and peaceful"

Iterate

Start broad, then refine:

1. "A male voice"
2. "A young male voice with energy"
3. "A young male voice with energy, like a sports commentator"

Limitations

• Consistency — Same description may produce slightly different voices
• Extreme requests — Very unusual voices may not generate well
• Accents — Some accents are better supported than others
• Singing — Designed for speech, not singing

Voice Design vs Voice Cloning

See Also

• Voice Cloning — Clone from audio samples
• Text-to-Speech — Standard TTS
• Models — Download models