Custom Voices creates a synthetic voice from just 10-30 seconds of audio. It needs one recording with the speaker’s consent and another as the model’s sample, then reproduces the speaker’s timbre and delivery.

Each voice gets its own ID and connects through the API to speech synthesis, the Realtime API, or GPT-Live voice agents. A store could use it for a brand voice, while a personal assistant could speak in its owner’s voice.

Access is limited to approved OpenAI customers, with consent required and a cap of 20 voices per organization. There is no broad public launch yet.