The Witcher 3 is getting a new expansion more than 11 years after it first released, and due to a health issue experienced by Geralt's Polish voice actor, CD Projekt Red will be using an AI tool to modify his voice.

Jacek Rozenek, who voiced Geralt in The Witcher 3's Polish dub, will be returning to voice Geralt in Songs of the Past. Rozenek notably suffered a stroke back in 2019 that affected his voice. Thanks to modern technology, CD Projekt Red is able to use an AI voice modulator, Respeecher, to alter the actor's voice to match his 2014 lines, as noted by Game File.

According to the post, Rozenek's stroke left him unable to even speak for a while, and he only gained his voice back after a ton of rigorous training. He was able to return for a couple of quests in the Next-Gen update that came out back in 2022, but told Game File that he "was so exhausted after this recording." Still, CD Projekt Red wanted him to return for the new expansion, so it had to think outside the box.

The main problem was that, after everything Rozenek went through, his voice was noticably different than it was in 2014 when he recorded the bulk of Geralt's lines for the original game. Rozenek's voice is now much lower pitched than it used to be, which would make any new lines sound odd when played next to the older ones that are supposed to take place in the same time period. Hence, the need for Respeecher.

Respeecher's model was trained on all of Rozenek's lines from the original game, but it sounds like this was doing a lot more than just running his voice through a quick filter. When asked about the process, Respeecher synthetic speech artist Dmytro Vasylets told Game File that "getting there took dozens of hours, training models, going through the details with the CDPR team, and dealing with AI artifacts that never fully disappear."

CDPR got Rozenek's blessing to use the tool, who told Game File, "I have great trust… for the creators of this game," and that, "when it comes to the dynamics of the voice, when it comes to the acting aspects, I feel very good, really very good."

Still, CDPR is aware of the optics of using AI anywhere near a voice actor, and it stressed to Game File that this was a special case. CD Projekt Red localization producer Mikołaj Szwed told the publication that the company wouldn't be using any AI tools to alter someone's voice without the express permission of that voice actor.

Even for The Witcher 4, which Rozenek is expected to return for, the tool won't be needed, due to Geralt being older and more grizzled, so a deeper voice won't be so jarring.

But while this seems like a good use of AI, the technology is still extremely controversial in gaming. Last year, the Indie Game Awards stripped the Game of the Year award from Clair Obscur: Expedition 33 after AI-generated placeholder textures were found in the game. Players have also found AI-generated art in Crimson Desert, though it's since been patched out.