Voice Agents

Build AI agents that speak and listen in real-time.

Voice is the most natural interface for AI, and 2025 is the year it became practical. With latencies under 300ms end-to-end, voice AI can now hold real conversations that feel natural — not like talking to an IVR system. OpenAI's Realtime API, ElevenLabs, and Deepgram have made this achievable for individual developers.

Building a voice agent requires understanding the full pipeline: audio capture and VAD (Voice Activity Detection) to segment speech, ASR (Automatic Speech Recognition) to transcribe it, LLM inference to generate a response, and TTS (Text-to-Speech) synthesis to speak it back — all faster than a human pause. Bottlenecks at any stage break the conversational flow.

In this track, I cover the OpenAI Realtime API (WebSocket-based, the lowest-latency option), ElevenLabs for production-quality voice synthesis with emotion control, Deepgram for enterprise ASR, and a complete project — an AI receptionist that handles phone calls via Twilio. The patterns here power real customer service bots in production.

5 Guides in This Track