SLNG.
Features

Voice Cloning

Overview

Voice cloning allows you to create custom AI voices that sound like specific speakers. This powerful feature enables personalized audio experiences, brand voice consistency, and accessibility solutions. slng.ai provides multiple models with different voice cloning capabilities to suit various use cases.

Voice cloning is available in select models - not all TTS models support this feature. This guide will help you understand which models to use and how to implement voice cloning effectively.

🎯 Models with Voice Cloning

✅ Full Voice Cloning Models

VUI - Basic Voice Cloning

  • Best for: Simple voice cloning, quick setup
  • Parameter: speaker_voice (base64 audio)
  • Quality: Good for basic applications
  • Languages: English only
  • Pricing: $0.10 per minute of audio

XTTS-V2 - Advanced Multilingual Cloning

  • Best for: High-quality voice cloning in multiple languages
  • Parameter: speaker_voice or speaker_wav (base64 audio)
  • Quality: Excellent, natural-sounding results
  • Languages: 17 languages supported
  • Pricing: $0.50 per minute of audio
  • Features: Speaker embedding, accent preservation

MARS6 - Professional Voice + Prosody Cloning

  • Best for: Professional applications, voice acting, brand voices
  • Parameter: audio_ref (base64 audio, required)
  • Quality: Studio-quality with prosody matching
  • Languages: 10 languages with regional variants
  • Pricing: $0.60 per minute of audio
  • Features: Voice cloning, prosody cloning, emotional control

Twi SpeechT5 - Specialized Language Cloning

  • Best for: Twi language applications
  • Parameter: Speaker embedding system
  • Quality: Native-sounding Twi speech
  • Languages: Twi only
  • Pricing: $0.25 per minute of audio
  • Features: Cultural accent preservation

ElevenLabs Models - Professional Voice Cloning

  • Best for: Production-grade applications, content creation
  • Parameter: Voice cloning API
  • Quality: Broadcast-quality voices
  • Languages: 29+ languages supported
  • Pricing: $0.20-$0.35 per minute of audio
  • Features: Advanced voice cloning, voice library management

❌ Models Without Voice Cloning

  • Orpheus: Pre-built voices only (tara, leah, jess, etc.)
  • Orpheus Indic: Pre-built Indian language voices
  • Kokoro: Single voice only

🎤 How Voice Cloning Works

1. Reference Audio Collection

Voice cloning requires a sample of the target voice speaking clearly.

Requirements:

  • Duration: 6-90 seconds (optimal: 15-30 seconds)
  • Quality: Clear speech, minimal background noise
  • Content: Natural speech, not singing or shouting
  • Format: WAV, MP3, or other common audio formats

2. Audio Processing

The model analyzes the reference audio to extract:

  • Voice characteristics (pitch, timbre, accent)
  • Speech patterns (rhythm, intonation)
  • Language patterns (pronunciation, dialect)

3. Voice Synthesis

When generating new speech, the model:

  • Applies the learned voice characteristics
  • Maintains natural speech patterns
  • Preserves accent and pronunciation
  • Generates audio in the cloned voice

🚀 Implementation Examples

Basic Voice Cloning with VUI

JSONCode
 
POST /tts/vui
Content-Type: application/json

{
  "text": "Hello, this is my cloned voice speaking.",
  "speaker_voice": "base64_encoded_audio_string",
  "language": "en"
}

Advanced Voice Cloning with XTTS-V2

JSONCode
 
POST /tts/xtts-v2
Content-Type: application/json

{
  "text": "This voice cloning is amazing!",
  "speaker_voice": "base64_encoded_audio_string",
  "language": "en"
}

Professional Cloning with MARS6

JSONCode
 
POST /tts/mars6
Content-Type: application/json

{
  "text": "Professional voice cloning with prosody matching.",
  "audio_ref": "base64_encoded_audio_string",
  "language": "en-us"
}

cURL Example

TerminalCode
 
curl -X POST https://api.slng.ai/tts/xtts-v2 \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "text": "Testing voice cloning capabilities",
    "speaker_voice": "base64_encoded_audio_string",
    "language": "en"
  }'

📱 Audio Preparation Best Practices

Recording Guidelines

  1. Environment

    • Quiet room with minimal echo
    • No background music or noise
    • Consistent microphone distance

  2. Speech Content

    • Clear, natural speech
    • Varied sentence structures
    • Include common words and phrases
    • Avoid monotone delivery

  3. Technical Requirements

    • Sample Rate: 16kHz or higher
    • Bit Depth: 16-bit minimum
    • Format: WAV preferred, MP3 acceptable
    • Duration: 15-30 seconds optimal

Audio Processing

Code
 
import base64
import wave

def prepare_audio_for_cloning(audio_file_path):
    """Convert audio file to base64 for voice cloning"""
    with open(audio_file_path, 'rb') as audio_file:
        audio_data = audio_file.read()
        base64_audio = base64.b64encode(audio_data).decode('utf-8')
        return base64_audio

# Example usage
base64_voice = prepare_audio_for_cloning("reference_voice.wav")

🌍 Language Support by Model

Multilingual Voice Cloning

ModelLanguagesRegional Variants
XTTS-V217 languagesen, es, fr, de, it, pt, pl, tr, ru, nl, cs, ar, zh, ja, ko, hu, hi
MARS610 languagesen-us, fr-fr, de-de, es-es, it-it, pt-pt, zh-cn, ja-jp, ko-kr, nl-nl
VUIEnglish onlyen
Twi SpeechT5Twi onlytw
ElevenLabs29+ languagesFull international support

💡 Use Cases & Applications

Business & Branding

  • Brand Voice Consistency: Maintain company voice across all content
  • Marketing Videos: Personalized customer communications
  • Training Materials: Consistent voice for corporate training
  • Product Demos: Brand-aligned product presentations

Accessibility & Inclusion

  • Screen Readers: Custom voices for users
  • Language Learning: Native speaker pronunciation
  • Assistive Technology: Personalized voice assistants
  • Educational Content: Consistent teaching voice

Content Creation

  • Podcasts: Guest voice cloning for consistency
  • Audiobooks: Character voice creation
  • Video Content: Voice-over in specific voices
  • Social Media: Brand voice for all content

Personal Applications

  • Voice Preservation: Clone voices for memory preservation
  • Custom Assistants: Personal voice for smart devices
  • Entertainment: Fun voice cloning applications
  • Accessibility: Personal voice preferences

⚠️ Ethical Guidelines & Best Practices

Consent & Permission

  • Always obtain explicit consent before cloning someone's voice
  • Respect privacy rights and personal boundaries
  • Use only for authorized purposes
  • Avoid deceptive applications

Content Guidelines

  • No harmful content generation
  • Respect copyright and intellectual property
  • Avoid impersonation without permission
  • Maintain transparency about AI-generated content

Quality Assurance

  • Test thoroughly before production use
  • Monitor for artifacts or quality issues
  • Validate results with human review
  • Maintain backup voice options

🔧 Troubleshooting Common Issues

Poor Voice Quality

  • Problem: Cloned voice sounds robotic or unnatural
  • Solutions:
    • Improve reference audio quality
    • Increase reference audio duration
    • Use higher-quality models (XTTS-V2, MARS6)
    • Check audio format and encoding

Accent Mismatch

  • Problem: Cloned voice doesn't match accent
  • Solutions:
    • Use language-specific models
    • Provide reference audio in target language
    • Use MARS6 for regional variants
    • Consider XTTS-V2 for multilingual support

Inconsistent Results

  • Problem: Voice varies between generations
  • Solutions:
    • Use longer reference audio (30+ seconds)
    • Ensure consistent audio quality
    • Use professional models (MARS6, ElevenLabs)
    • Maintain stable API parameters

📊 Cost Optimization

Model Selection by Budget

Budget LevelRecommended ModelCost per Minute
BudgetVUI$0.10
StandardXTTS-V2$0.50
ProfessionalMARS6$0.60
EnterpriseElevenLabs$0.20-$0.35

Usage Optimization Tips

  • Batch processing for multiple audio files
  • Cache voice embeddings for repeated use
  • Use appropriate model for quality requirements
  • Monitor usage and optimize accordingly

🔗 Quick Links

📞 Need Help with Voice Cloning?

Having trouble with voice cloning? Our team can help you:

  • Optimize your reference audio
  • Choose the right model for your use case
  • Troubleshoot technical issues
  • Scale your voice cloning implementation

Contact us: Voice Cloning Support

Last updated: June 2025

Last modified on
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