But will his voice carry?

Ira Glass was talking a blue streak, sipping takeout soup with a plastic spoon, bent over himself in a chair on a dog day afternoon in a Manhattan editing studio, explaining how fans of his Chicago-based public radio program, “This American Life,” react when they find out he’s attempting to cross over to television.

“They go, ‘Ohhh ...’ -- like, ‘Please, don’t,’ ” he said in the unradiolike voice that is his trademark. “I think there’s a part of the public radio audience that views any move to television as a step down.” He sat up and threw his shoulders back in an upright posture, as if remembering instructions. Sighed.

Glass had been commuting to New York to produce a presentation tape for Showtime, which wants to turn “This American Life” -- heard locally on KCRW-FM and KPCC-FM and which has developed a cult following of 1.5 million listeners over the last decade with its idiosyncratic mix of character-driven stories -- into a TV series.

Glass has carved out an alternative niche in the cultural landscape, helping to launch the careers of writers David Sedaris, David Rakoff and Sarah Vowell in the process and making him an obvious target for mainstream media looking for the next bright idea. But can his original sensibility translate from the intimate airwaves to the masses?

Why is he throwing his formidable creative drive into taking the risk?

“Television is the medium of our time,” Glass said, after dismissing his ambitious experiment several times as “a lark.” “And it would be fun to be working in the medium that most people turn to for stories and feelings and a sense of what’s going on in the world rather than trying to do all of that in a medium that most of the country and most of the world gave up on -- for that -- 50 years ago.”

This isn’t the first time Glass has flirted with the idea of taking his show to Hollywood. In 1999, he wrote a diary in Slate magazine from Los Angeles about pitching the networks. He turned down two pilot offers, wanting more editorial control and freedom to walk away. The following year, he used spare radio funds to film a documentary with a director he admires, Bennett Miller, that didn’t really work. So Glass gave up, he said, until Showtime approached him two years ago.

Christine Vachon, co-president of Killer Films, known for her taste in risky projects and fierce protection of visionary directors, came on board as a producer.

“Ira wants a tremendous amount of creative control over his material,” said Vachon in her Greenwich Village office. She and Glass were semiotics majors and good friends at Brown University. “For a lot of potential TV producers that was scary. We’re used to dealing with directors who have a very specific vision and who have an intrinsic sense that protecting not just the vision itself but the process is what will make their work strong.”

Showtime commissioned a 20-minute “pilot presentation,” industry jargon for a shorter, cheaper version of a pilot. John Moser, the Showtime executive who worked closely with Glass during the editing process, said the network and Killer Films “have tried to surround him with really good people, like a first-time director.”

Glass started trying to adapt his show to the small screen using the “This American Life” blueprint -- with its mood-setting opening prologue, an introduction of the week’s theme, followed by one or more “acts,” or related stories.

Glass has never had what is considered a voice for radio -- which, depending on whom you talk to, is his strength or his downfall. But does he have a face for TV?

His high-spirited program intro sounds the same on TV as it does on the radio: “It’s ‘This American Life.’ I’m Ira Glass,” except, there he is -- Ira Glass! -- not merely a voice but a 46-year-old man with an ageless face and graying temples, nerdily handsome in his oversized black-framed glasses, dressed up in a shapeless black suit. “Each week on our show we choose some theme, bring you a variety of different kinds of stories on that theme ...”

“The first time I saw him on camera, I’m like, ‘Whoa! This is different,’ ” Moser said.

“There are huge ‘This American Life’ junkies, and I don’t know if they’ve seen Ira. And Ira is a character -- he’s got those great glasses, he’s very charming.

“But for those people who know the show but don’t know the face, there’s going to be a period of adjustment.”

Exactly how Glass’ physical presence would be integrated into the show is up for debate. But if he has always made a point of not sounding like anyone else on the radio, it seems that he wants to look more like everyone else on TV. The radio host who long refused to have his photograph taken in the name of not being seen -- a stance he has loosened over the years with press attention, live shows and appearances on “The Late Show With David Letterman” -- dropped 30 pounds in preparation for his close-up. “I decided I needed to lose weight,” he said. “Because I have seen the people on the TV, and they tend to be very thin.”

In a Manhattan studio in early June, Glass was shooting the prologue to a program whose theme is “reality check.” Longtime “This American Life” contributor and journalist Jack Hitt was getting his face done in the dressing room, preparing to retell a radio story about hacking into the computer at his first newspaper job, only to accidentally discover he is the worst-paid reporter in the newsroom.

“Do I look like a scary old guy?” he asked, looking into the mirror at his graying mane. “I look like I play guitar for the Eagles.”

In the nearby studio, director Chris Wilcha called, “Action!” and Heather McElhatton, a Minnesota Public Radio reporter, retold a story about the time she peed on the school bus, forever altering her grade-school fate. “... So when the bus lurched forward,” McElhatton said to Glass, who was clutching a vessel of coffee in one hand, crouching his tall frame down at eye-level with the camera so that McElhatton could tell the story directly to him, “all the pee rolled to the back of the bus. And kids have a really high pee radar, so

“Peedar, we call it,” Glass interjected.

“Peedar,” McElhatton repeated, taking a deep breath and starting over: “OK, so kids have a really high ‘peedar.’ ”

“No, no, I’m sorry!” cried Glass as the bystanders broke into a laugh. “I was just making a dumb joke!”

They took it from the top, but McElhatton had grown a little self-conscious and tripped over her words. Glass said in a jokey, I’m-playing-director voice: “OK, here’s who you are. You’re playing this Heather character ...”

This was Glass in his element: creating the fleeting on-air intimacy that is a key to his success; isolating the spontaneous narrative moment that illuminates a larger idea; goofily charming the room.

Learning the ropes

The master of his own on-air radio universe, Glass combines narration, interviews, sound effects, silence and music in a process he has always described as making little movies for radio -- which, it turns out, is a lot different than making little movies for TV. A radio story about 18 people getting struck by lightning in Chicago in a single month appears to be perfect pilot material, Glass said, but “the pictures make it seem more fake rather than something real that actually happened to people that’s incredible.” Jokes that work on the radio bomb with images behind them. An interviewee sounds charming on the air and comes off like a politician on TV “through a sheer accident of self-presentation.”

Glass said he wants to make cinematic stories about real life that “don’t look like reality TV or a documentary or ‘20/20,’ ” television that “does not look like anything else on television.”

But Glass has grown accustomed to telling stories in the dark. And throughout the process, Glass -- moviegoer, brother of Disney executive Karen Glass, consumer of television -- struggled to communicate in a visual language that he had admired only from afar.

He called the images “pretty” and “beautiful” but seemed unsure of what to do with them once they were in his very own hands.

The pilot presentation features one story that Glass reported simultaneously for TV and radio, about Ralph and Sandra Fisher, a Texas couple who cloned their beloved pet bull. Another piece, about the New York-based Improv Everywhere, was produced with inherited footage -- which taught Glass the narrative pitfalls of making filmed stories about things that have already happened, which is routine on the radio, but lacks drama on screen.

During an edit meeting in early June, Glass; Julie Snyder, his senior producer and right hand; and producer Jane Feltes joined the TV people -- Wilcha and editor Jenny Golden -- in a windowless editing studio to look at half an hour of rough footage of the bull story. Glass said his reaction shots were “awkward” and “embarrassing” and, eventually, they disappear from the final cut. “Like, am I wrong?” he asked. “Don’t I look sort of like a dope?” He decided that over-the-shoulder shots of him talking to Ralph looked “like we’re on some bad TV newsmagazine.”

Cut.

In one scene, Sandra retrieved the skinned hide of the dead bull from a box in the closet while Glass described it in voice-over as “a balloon emptied of air.” It felt like a simultaneous translation, audio for the vision impaired. After a moment, it dawned on Glass that his evocative image had been hijacked by the image itself. He’s not used to this.

“When you have pictures, there is so much you don’t need to say,” Golden said later. “We really had to try and cleave Ira from narrating every emotional moment. You can completely understand why that’s his impulse -- but definitely he needs to kind of recalibrate his impulses. I would feel sometimes like, ‘Wow, that was three days getting to a place that we knew we had to get to in the beginning.’ ”

“We took out what was for me a shocking amount of exposition,” Glass said. “Every time Jenny would say, ‘We’re gonna take this out and it’s gonna be better,’ I would feel my entire body clench up inside with, like, the utter wrongness and stupidity of what she was saying. And she was basically always right.”

Time and again, Glass seemed unable to reconcile himself with the pace of a TV story -- in which the mind reads images faster than the speed of a narrator, leaving him no room to do what he knows best. “You want your craft to support the idea that any thought you’re having about the story, any funny moment, any emotional thing that happens that gets to your heart the most, you’ll be able to squeeze into the story even if it takes you off the path of the plot,” he said.

While working on the radio and TV versions of the bull story, he couldn’t shake the feeling that without the revealing exchanges of human conversation that are the stock and trade of his radio show but tend to drag on screen, the TV story lacked heart. “I thought, ‘Well, maybe this TV story is good,’ ” he said by phone after seeing the first edit of the bull story, “but if it is, it’s not good in the way that I’m used to things being good, which would include this kind of moment where people interact.”

“I think I wanted them to fall in love with images more,” said Wilcha, who replaced another director, David Schisgall (“The Lifestyle”), a few months ago, “and I don’t know that that happened. They never confessed to me any epiphanies they were really having about the process. They never said to me, like, ‘Wow, I really see that, you know, images can do X, Y and Z.’ I wanted them to see that just experiencing a collection of images could lead you to the same place that words might.”

A few weeks later, once the DVD had been shipped off to the decision-makers at Showtime, Glass said by phone: “I have to say I’m sort of surprised at how good it is. If anything, what I’ve learned in this process is that there’s a power to these TV stories that is built out of something very different than on the radio show.” His voice went dead for a beat. “Now I see that, but I don’t exactly know what to do with it.”

If Glass “reinvented radio,” as David Mamet once wrote, it seemed that he was still trying to teach himself how to reinvent television.

Did he want to keep trying to figure it out, if Showtime gives him the green light?

He hemmed, hawed, sighed. Finally he gave his version of a straight answer: “When in your 40s do you get to actually, like, try something you’ve never tried and learn something new? So that’s the great thing. But once you get into it, it’s also the terrible thing. Because it’s terrible to feel stupid again. And I felt stupid every day for the last two weeks.”

Showtime has asked Glass for minor editorial revisions -- to clarify the prologue’s connection to the rest of the show, to rework some of the second act -- before it goes back to the network for a final decision in September. And in what he sees as a positive step forward, it’s asked him for a budget estimate.

“We think the work is very good and very impressive,” Moser said by phone, “especially for a first-time filmmaker.” He added that the final decision will be up to Robert Greenblatt, Showtime’s president of entertainment, and will include budgetary and overall programming factors.

Meanwhile, back in Chicago, Glass was weighing the potential consequences of turning this fling into a full-time mistress while keeping things going at home on the radio show. “There are pros and cons, and I don’t know where I come down,” he said.

It seemed important to him to remind himself that he had an out. “We haven’t even talked about what happens if we want to do a story and they don’t want us to do it. Or whether the mix of stories on the TV would be the same as on the radio show. I mean, we did an hour in Iraq last year. We did an hour a month ago on a guy who was set up by the U.S. government under the Patriot Act. Can we do what would count as political stories? We haven’t even broached that. And it’s not clear: Can they take what we’ve done, recut it any way they want and put it on TV?”

He took a gulp of air. “If I get the right deal -- the right money, the right creative control -- I would do it.”