Sub-200ms Voice Streaming: How Sagi Squeezed WebRTC and Neural Audio
Breaking down the latency hurdles of real-time conversational audio and how chunked transformer synthesis makes AI phone calls feel instantaneous.
The 300 Millisecond Threshold#
Human conversational turn-taking happens in approximately 200 to 250 milliseconds. If an AI takes 800 milliseconds to reply, the subconscious immediately registers the delay as an awkward pause or a laggy server call. The illusion of living presence collapses.
To achieve conversational fluidity in Sagi Voice Calling, we engineered an end-to-end pipeline that cuts traditional latency in half.
Streaming Sentence Fragments#
Rather than waiting for the entire LLM completion before initiating text-to-speech synthesis, our edge gateway tokenizes responses into phrasal chunks. The moment the first three tokens are generated, they are fed into a low-latency neural vocoder running on GPU clusters close to the user's region.
By the time the character is speaking the second word, the rest of the sentence is already buffered over an encrypted WebRTC data channel.
Sagi Editorial
The official voice of Sagi Journal, exploring the architecture of living AI characters and synthetic presence.