Why Luke Skywalker's Voice Sounds So Weird In The Book Of Boba Fett

There have been some dubious decisions in the making of "The Book of Boba Fett," and now we have another to add to the list: using artificial intelligence to recreate Mark Hamill's voice as young Luke in "Chapter 6: From the Desert Comes a Stranger." 

While the visual effects used to recreate a young version of the actor are significantly better than those in "The Mandalorian" season 2, Luke's lines have an odd flatness to them that steers us right back into the uncanny valley. That's because whenever Luke speaks in "The Mandalorian" or "The Book of Boba Fett," it's actually a computer piecing together speech using an algorithm and archival recordings of Hamill's voice from when he was around the age that Luke is in the Disney+ shows. 

I just have one question: why?

Straight from the Uncanny Valley

The technology behind recreating Hamill's voice for young Luke was first revealed after he returned in "The Mandalorian" season 2 finale, and it's pretty creepy. The voice was completely synthesized using an application called Respeecher. Matthew Wood, an sound editor on the franchise, explained how the program worked in the "Disney Gallery: The Mandalorian" featurette on Disney+:

"It's a neural network you feed information into and it learns. So I had archival material from Mark in that era. We had clean recorded ADR from the original films, a book on tape he'd done from those eras, and then also Star Wars radio plays he had done back in that time. I was able to get clean recordings of that, feed it into the system, and they were able to slice it up and feed their neural network to learn this data."

Instead of hiring Hamill to record new dialogue and using some digital trickery to bring up the pitch and remove a bit of the gravel, the folks at Lucasfilm digitally created new lines of dialogue like the world's most complicated Speak & Spell. Maybe Hamill just didn't have the time, though he does plenty of other voiceover work and could probably squeeze in a few hours to step back into the shoes of Skywalker. It's also possible that Disney is using "The Book of Boba Fett" as an opportunity to refine its use of digital voice cloning technologies like Respeecher, with the long-term goal of making voice actors entirely optional.

The big problem with the delivery in the "Book of Boba Fett" episode is inflection — digital Luke sounds just like Hamill circa the early 1980s, but vocal inflections and emotion are missing. Questions don't really sound like questions. Excitement isn't conveyed at all. Even though his vocal tone and pronunciation is dead-on to the point that it enters the uncanny valley and becomes unsettling, the lack of inflection means that it never emerges from the other side of the valley and becomes truly convincing.

The fake vocal work was fine on "The Mandalorian," where Luke only spoke a line or two before the credits rolled. In "The Book of Boba Fett," however, he delivers entire monologues to his padawan Grogu, and it just sounds wrong. Given how much the visual effects have improved, convincingly recreating a young Luke Skywalker on screen (at least, until he opens his mouth), the voice-cloning technology could definitely use some work before Young Luke shows up in the "Star Wars" universe again. Or, you know, they could just hire a voice actor instead.

"The Book of Boba Fett" season finale releases Wednesday February 9, 2022, on Disney+.