ElevenLabs Voice Agent

Build AI phone agents using ElevenLabs Conversational AI API + Twilio.

Setup Flow

1. Create agent via ElevenLabs dashboard or API
2. Configure voice, TTS model, LLM, and system prompt
3. Purchase/connect Twilio phone number via ElevenLabs phone integration
4. Test and iterate on script, voice settings, turn-taking

Optimal Voice Settings (Proven)

Recommended Voices

• Alexandra (kdmDKE6EkgrWrrykO9Qt): Pleasant female, great for cold calls
• Hope (OYTbf65OHHFELVut7v2H): Warm female backup

LLM Choice

Use gpt-4o-mini for phone agents — speed is critical, latency kills calls.

Key API Endpoints

POST https://api.elevenlabs.io/v1/convai/agents/create
PATCH https://api.elevenlabs.io/v1/convai/agents/{agent_id}
GET https://api.elevenlabs.io/v1/convai/agents/{agent_id}
POST https://api.elevenlabs.io/v1/convai/twilio/phone-numbers — Connect Twilio number

Enable Phone Features

Enable these tools on the agent: voicemail_detection, end_call, background_voice_detection

NEPQ Sales Framework

For appointment-setting agents, use Neuro-Emotional Persuasion Questioning:

• Permission-based opening ("Do you have a quick moment?")
• Question-led qualification (don't pitch, ask)
• Emotional connection questions before booking
• Soft close with specific time options

Twilio Integration

1. Get Twilio Account SID + Auth Token
2. Use ElevenLabs API to create phone number connection
3. Phone number is provisioned automatically by ElevenLabs
4. Calls route: Twilio → ElevenLabs → AI agent

Common Issues

• Robotic voice: Switch to v3 conversational model, enable expressive mode
• Slow responses: Use gpt-4o-mini, increase streaming latency optimization
• Cuts off caller: Increase turn timeout, reduce eagerness
• Sounds scripted: Add personality to system prompt, lower stability slightly