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Why Voice Matters

The voice is your agent’s first impression. Research consistently shows:
  • Users form an opinion about an AI agent within seconds
  • The wrong voice makes even a well-configured agent feel unprofessional
  • The right voice builds trust instantly

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TTS Providers at a Glance

ProviderQualityLatencyCostBest For
Cartesia Sonic⭐⭐⭐⭐⭐Very Low$$Most use cases — best overall balance
OpenAI TTS⭐⭐⭐⭐Low$$Natural, conversational feel
ElevenLabs⭐⭐⭐⭐⭐Medium$$$Premium quality, emotional range
Short answer: Start with Cartesia. If you need a premium, highly realistic voice, use ElevenLabs.

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Cartesia Voices

Cartesia is the most popular choice among TalkifAI users — lowest latency with a natural, clear sound.
VoiceGenderToneBest For
Sonic EnglishNeutralClear, professionalCustomer support, general purpose
Barbadian ManMaleWarm, friendlySales, outbound calls
British LadyFemalePolished, formalFinance, legal, insurance
Australian ManMaleCasual, approachableTech support, startups
French ConversationalFemaleSmooth, elegantLuxury brands, premium services
Indian ManMaleClear, professionalBusiness, enterprise
Visit cartesia.ai/voices to preview voices live in the browser. Copy the Voice ID from there and paste it into your agent settings.

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OpenAI TTS Voices

Simple, consistent, and natural — OpenAI’s built-in voices require no external account.
Voice IDCharacterBest For
alloyNeutral, clearGeneral purpose
echoMale, deepProfessional, authoritative
fableMale, warmFriendly, storytelling
onyxMale, deep richPremium, formal contexts
novaFemale, warmSupport, approachable interactions
shimmerFemale, softCalm, gentle conversations

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ElevenLabs Voices

ElevenLabs delivers the highest quality — the most human-like voices available. The tradeoff is slightly higher latency and cost.

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When to Use ElevenLabs

  • You need a premium brand image
  • Emotional range matters (sympathy, enthusiasm, warmth)
  • Realism is more important than speed
  • You can tolerate an extra 100–200ms of latency
VoiceTypeDescription
RachelFemaleNatural, conversational, US accent
AdamMaleDeep, authoritative, articulate
BellaFemaleSoft, warm, friendly
AntoniMaleProfessional, neutral
JoshMaleYoung, energetic
Find your Voice ID in the ElevenLabs dashboard under Voice Library. Paste it into the Voice ID field in your agent settings.

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Choose by Use Case

Recommended: Cartesia Sonic or OpenAI novaWhy: Warm, approachable, and clearly articulated. Soothing when customers are frustrated.Settings:
  • Speed: 1.0x (default)
Recommended: Cartesia Barbadian Man or ElevenLabs JoshWhy: Energetic and engaging — holds attention. Lower disconnect rates on cold calls.Settings:
  • Speed: 1.05x — slightly faster projects confidence
Recommended: OpenAI shimmer or a calm Cartesia female voiceWhy: Calm, reassuring tone. Patients are often anxious — a soothing voice genuinely helps.Settings:
  • Speed: 0.95x — slightly slower for clarity
Recommended: Cartesia Australian Man or OpenAI echoWhy: Casual and modern — matches a startup’s brand voice without being too formal.Settings:
  • Speed: 1.0x

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Voice Settings

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Speed (0.5x – 2.0x)

SpeedUse Case
0.8x – 0.9xMedical, elderly users, complex information
1.0xGeneral use (recommended default)
1.1x – 1.2xSales, energetic conversations
Avoid going above 1.3x — the agent sounds robotic and users disconnect.

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Stability (ElevenLabs Only)

  • High (0.8+): Consistent, less expressive — good for formal contexts
  • Low (0.3–0.5): More expressive, natural variation — good for emotional conversations

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Style (ElevenLabs Only)

  • 0.0 = Neutral
  • 0.5 = Moderate expression
  • 1.0 = Maximum style and emotion

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How to Test Your Voice

After saving the agent:
  1. Go to Studio → Agent → Test
  2. Speak a few sentences and listen carefully
  3. Check:
    • Is pronunciation correct?
    • Does the speed feel natural?
    • Does the tone match the use case?
  4. Adjust → save → test again
Test these sentences: 
"Hello, my name is Aria. How can I help you today?"
"Could you please provide me with your order number?"
"Let me check that for you — just one moment."
"Your issue has been resolved. Is there anything else I can help with?"

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Next Steps

Create Your Agent

Voice selected — go complete your agent setup.

Test Your Agent

Test the voice properly before going live.