CD Projekt used AI to adjust actor's voice in Polish version of Blood and Wine

What CD Projekt did

CD Projekt used AI voice tools in the Polish version of The Witcher 3: Blood and Wine to bring Jacek Rozenek's new recordings closer to his older performance as Geralt. The actor recorded his lines for the expansion as usual, and the studio then sent them to the AI firm Respeecher for processing, according to StopGame News.

Respeecher's tools were trained on Rozenek's earlier work. The studio wanted the new Polish lines to sit alongside recordings made years before, including lines that play in parts of the game that existed before Blood and Wine.

Why the voice needed adjusting

Rozenek went through rehabilitation and gradually recovered his speech. He had already recorded lines for the quest In the Shadow of the Eternal Fire, added to The Witcher 3 with the next-gen update in 2021. He said that session left him exhausted.

When work began on Blood and Wine, the team wanted Rozenek back but did not know whether it was possible given his health and the size of the role. Localization producer Mikołaj Szwed said the studio needed to hear how much the actor's voice had changed over time and after his illness. It had become lower and hoarser, Szwed said, and players would notice the difference.

Consent and earlier use

Rozenek supported the decision. He said the main thing was that the voice sound as close as possible to his voice from twelve years earlier, and that he trusted the game's creators.

Szwed said CD Projekt understands ethical concerns about AI but that in this case the technology kept the actor in the role. He described it as a case where AI can be used ethically, with the person's consent and for a good cause. The studio would not have used AI without Rozenek's health problems, he said.

CD Projekt and Respeecher had worked together before. The studio used the company's tools to recreate the voice of Miłogost Reczek, who had died, for additional lines as Viktor Vektor in Cyberpunk 2077: Phantom Liberty.

Release timing

Blood and Wine is expected in 2027. A remaster of The Witcher 3, free for owners of the game, was released in late September. A new Witcher game with Ciri as the lead character is expected in 2028.