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Voice Configuration Parameters

After selecting your voice, you can adjust provider-specific settings to fine-tune how it sounds. The current dashboard exposes adjustable voice parameters for ElevenLabs voices. Azure Speech and Cartesia voices use their provider defaults in the itellicoAI interface.
Voice settings are displayed dynamically based on your selected voice. If your selected provider does not expose adjustable settings, choose a different voice or provider instead. Changes apply immediately to new conversations.

ElevenLabs Settings

ElevenLabs voices support the following adjustable parameters:

Stability

Controls consistency and expressiveness (range: 0.0-1.0, itellicoAI default: 0.71) How it works:
  • Lower values (0.3-0.5): More expressive and varied, but less consistent between generations
  • Medium values (0.5-0.7): Balanced expressiveness and consistency (recommended)
  • Higher values (0.7-1.0): More consistent and predictable, but may sound monotone
Recommended starting point: 0.5-0.7 Use lower stability for creative applications where variety is desired, and higher stability (0.6-0.85) for consistent customer service responses.

Similarity Boost

Controls how closely the voice matches the original speaker (range: 0.0-1.0, itellicoAI default: 0.75) How it works:
  • Lower values (0.5-0.7): More creative interpretation of the voice
  • Medium values (0.75-0.8): Balanced adherence to original voice (recommended)
  • Higher values (0.8-1.0): Strict matching to original voice character
Recommended starting point: 0.75-0.8 Higher values increase processing demands and can add latency. They’re also more likely to reproduce artifacts if the source voice data is noisy.

Style

Controls stylistic variation in pacing and intonation (range: 0.0-1.0, itellicoAI default: 0.0) How it works:
  • 0.0: Neutral delivery (recommended)
  • 0.5-1.0: Amplified style of the original speaker
Recommended starting point: 0.0 Higher style values can make voices less stable and add latency. Keep this at 0 for most use cases.

Speaker Boost

Enhances clarity and presence (boolean, itellicoAI default: enabled) How it works:
  • Enabled: Boosts similarity to the original speaker, improving clarity
  • Disabled: Standard processing
Recommended starting point: Enabled Increases latency slightly; subtle effect.

Speed

Controls playback speed (range: 0.7-1.2, itellicoAI default: 1.0) Speed values:
  • 0.7-0.9: Slower, clearer delivery
  • 1.0: Normal speed (default)
  • 1.1-1.2: Faster, more energetic delivery
Recommended starting point: 1.0 Adjust in small increments (0.05-0.1) and test with full conversations.

Other Voice Providers

Azure Speech and Cartesia voices do not currently expose adjustable voice-parameter controls in the itellicoAI dashboard. For these providers, focus on choosing the right voice, language, and provider during voice selection.
Provider defaults are still optimized for real-time conversations. If you need a different speaking style, compare multiple voices from the same provider before switching providers.

Adjusting Settings

How to Change Voice Settings

  1. Navigate to GeneralSpeaking in your agent editor
  2. Your currently selected voice is displayed in the “Current Voice” card at the top
  3. Click the gear icon next to your current voice (available for ElevenLabs voices)
  4. A settings panel opens with adjustable parameters for your voice
  5. Adjust sliders or toggles as needed
  6. Click Save Changes to apply

Common Settings by Use Case

ElevenLabs:
  • Stability: 0.60-0.85
  • Similarity: 0.75-0.85
  • Style: 0.0
  • Speed: 0.95-1.05
Goal: Clear, steady, professional
ElevenLabs:
  • Stability: 0.45-0.70
  • Similarity: 0.70-0.80
  • Style: 0.0
  • Speed: 1.05-1.15
Goal: Energetic, confident, engaging
ElevenLabs:
  • Stability: 0.60-0.85
  • Similarity: 0.75-0.85
  • Style: 0.0
  • Speed: 0.95-1.0
Goal: Clear, patient, instructional
ElevenLabs:
  • Stability: 0.70-0.85
  • Similarity: 0.80-0.90
  • Style: 0.0
  • Speed: 0.9-1.0
Goal: Calm, consistent, professional

Best Practices

Start with recommended defaults: Itellico defaults are optimized starting points. ElevenLabs recommends stability ≈0.5 and similarity ≈0.75-0.8 as common baselines. Make small changes: Voice settings are sensitive. Adjust in small increments and test after each change. Test in context: Use full conversation scenarios (3-5 minutes), not just single-sentence samples. You can also add ambient sound to create a more natural atmosphere. Consider your audience: Older customers often prefer slightly slower speeds. Younger audiences may prefer slightly faster. Understand response time trade-offs: Higher similarity boost and speaker boost increase latency. Style values >0 can also add latency and reduce stability. Document your settings: Keep track of what works for each use case and voice combination.

Next Steps

Custom Pronunciations

Correct pronunciation of brand names and technical terms

Ambient Sound

Add background ambience to calls

Select Voice

Choose a different voice

Test Your Agent

Test your voice settings with web calls