The green, floppy-eared dog can be programmed to say a child's name, favorite food or favorite animal in Ibsen's voice.
"I have always thought that [the voices] were 45-year-old women," Hartlaub tells NPR's Melissa Block. "And then to find out that he was actually a kid was a surprise for me."
Hartlaub says his curiosity about the voices behind inanimate objects began when he found out that Bart Simpson was actually voiced by a grown woman.
"I started to get suspicious every time I heard an animated character," he says. "And then my children started getting talking toys as gifts ... and that suspicion continued."
Hartlaub says he was impressed by Ibsen's professionalism in the studio, often needing only one take to get it right. And he's not the only one.
For the first installment of his Talking Toy Project, pop culture critic Peter Hartlaub found the voice behind LeapFrog's My Pal Scout.
"They're all in awe of him; he's like a rock star when he walks into LeapFrog," Hartlaub says.
After tracking Ibsen down, Hartlaub has set his sights on the voice behind Farmer Tad, a character from LeapFrog's Fridge Farm Magnet Animal Set. He's planning a road trip to visit the woman who provides the squeaky plea, "Hi, I'm farmer Tad! Listen to my banjo."
An Iron Man toy and the Radio Flyer Retro Rocket are also on the list. Hartlaub says he envisions a man with huge deltoids belting out, "Retro Rocket!" But he knows he will probably be completely shocked when he finds out who it really is.
"Who knows? It could be anybody. That's what's part of the fun of this."