impossible → routine
Conversation at speaking speed
Holding a spoken conversation with a model at the pace people actually talk.
Impossible
ChatGPT gets voice as a relay — Whisper transcribes the speech, the text model composes a reply, and a separate synthesizer reads it out.
source1 year, 1 month
Routine
GPT-4o's system card records the model answering speech directly in 320 milliseconds on average — the speed of human conversational turns.
232 ms fastest, 320 ms average
source