2 posts tagged with "elevenlabs"

Pick a voice stack and you are really picking two things: who owns the audio transport, and what you can see when a turn goes wrong. The vendor list barely matters — LiveKit Agents and Pipecat both put the same speech-to-text, language model and text-to-speech providers behind the same three seams, and both let you swap any of them in a line.

LangSmith shipped tracing for both in July, alongside OpenAI Realtime and Gemini Live. That is a useful forcing function for this comparison, because a trace shows you where a framework's abstraction actually sits — and the two answers are genuinely different.

Here is a fact that should make telephony simple. A Twilio call carries μ-law audio at 8000 Hz, and ElevenLabs' text-to-speech API will produce exactly that if you ask for the ulaw_8000 output format. One vendor's output is the other vendor's wire format. No resampling, no transcoding.

And yet none of the four common ways to put an ElevenLabs voice on a Twilio call just passes those bytes through. Each one converts somewhere, and where it converts tells you who is in charge of the audio.