Building a real-time conversational voice stack requires solving the critical challenge of latency and synchronization between speech-to-text (STT) and text-to-speech (TTS) systems. This practical guide details how to orchestrate Deepgram and PlayHT using a Node.js server to achieve sub-500ms round-trip latency. The architecture focuses on streaming audio chunks to Deepgram for immediate transcription and using PlayHT for low-latency audio generation, managed by a central server to prevent buffer misalignment and audio cutoffs.

This approach ensures proper barge-in handling, allowing users to interrupt the AI without audio overlap. Key implementation steps include configuring WebSocket connections for Deepgram, managing audio buffers, and handling edge cases like reconnection logic and race conditions. By following this tutorial, developers can avoid common pitfalls such as jitter and audio corruption, creating a seamless voice interface suitable for production environments.