OpenAI details 5-month casting call that picked ChatGPT's voice

OpenAI published a detailed timeline and casting breakdown Wednesday in an effort to clarify how the voice of Sky came to be, responding directly to public speculation that it was designed to mimic Scarlett Johansson. The company says Sky belongs to a different professional actress using her natural speaking voice and was cast months before any conversation with Johansson began. CEO Sam Altman acknowledged the confusion in a statement: “The voice of Sky is not Scarlett Johansson’s, and it was never intended to resemble hers.” Out of respect for Johansson, OpenAI has paused using Sky in its products, and Altman apologized for not communicating better.

The post lays out a surprisingly thorough process. In early 2023, OpenAI partnered with casting directors and producers to define criteria for the voices — approachable, trustworthy, warm, charismatic, and with a rich tone that feels timeless. On May 10, 2023, the casting agency put out a call for talent and received over 400 submissions in under a week. The casting team independently winnowed that to 14 actors, then presented their top picks to OpenAI. After conversations with each actor about the vision, risks, and safeguards of human-AI voice interactions, an internal team selected the five final voices: Breeze, Cove, Ember, Juniper, and Sky.

The timeline gets specific when it comes to Johansson. Altman first spoke with her and her team on September 11, 2023 — well after Sky had been cast and recorded — to discuss her joining as a potential sixth voice. She declined a week later through her agent. The five selected voices launched into ChatGPT on September 25. OpenAI says all actors flew to San Francisco for recording sessions in June and July and are paid above top-of-market rates for as long as their voices remain in the product.

What stands out here isn’t just the casting rigor but the defensive posture. The company clearly felt pressure to prove Sky wasn’t a Johansson clone, down to listing the exact date Altman first called her agent. It’s a rare, almost uncomfortable level of transparency from a company that typically plays things close to the chest. Whether that satisfies critics or just gives them a tighter timeline to pick apart is an open question.