February 10, 2026

How AI Voice Technology Actually Works

Ever wondered how an AI can hold a natural phone conversation in Danish? Here's a look under the hood at the technology that powers BlomJacobsen.

The Three-Step Pipeline

Every AI phone call follows a three-step process:

1. Speech-to-Text (STT) When a caller speaks, their voice is captured and converted to text in real time. We use Deepgram's speech recognition engine, which has been optimized for Danish language with high accuracy even in noisy environments.

2. AI Processing The transcribed text is sent to a large language model (like GPT-4 or Claude) that understands the context of the conversation, determines the appropriate response, and generates natural reply text. This is where the "intelligence" lives — the AI can handle complex questions, multi-turn conversations, and business-specific scenarios.

3. Text-to-Speech (TTS) The AI's text response is converted back into spoken Danish using ElevenLabs' voice synthesis technology. The result is a voice that sounds remarkably natural, with appropriate intonation, pacing, and emphasis.

The Orchestration Layer

Tying it all together is the telephony layer — powered by Vapi and Twilio — which manages the actual phone call, handles turn-taking, and ensures low-latency communication. The entire round-trip from caller speech to AI response typically takes under 1 second.

Why Danish Matters

Not all AI voice systems support Danish well. BlomJacobsen specifically optimizes each component of the pipeline for Danish language, ensuring natural conversations that your customers trust.