Editor's note: TED is a nonprofit organization dedicated to "ideas worth spreading" which it makes available through talks posted on its website.

(CNN) -- For a man whose life has been built around communication, the loss of the ability to speak is a particularly cruel fate. But it's one that film critic Roger Ebert demonstrated that he could overcome, in a talk at the TED 2011 Conference in Long Beach, California, in February.

"These are my words, but this is not my voice," Ebert told the audience of nearly 2,000. "This is Alex, the best computer voice I've been able to find, which comes as standard equipment on every Macintosh. For most of my life, I never gave a second thought to my ability to speak. It was like breathing. In those days, I was living in a fool's paradise. After surgeries for cancer took away my ability to speak, eat or drink, I was forced to enter this virtual world in which a computer does some of my living for me."

Ebert, wearing a facial prosthesis and typing on his MacBook, was joined by his wife, Chaz, and friends John Hunter and Dean Ornish in making the presentation.

Chaz was the one who read this part of Ebert's talk: "It was Chaz who stood by my side through three attempts to reconstruct my jaw and restore my ability to speak. Going into the first surgery for a recurrence of salivary (gland) cancer in 2006, I expected to be out of the hospital in time to return to my movie review show, 'Ebert and Roper at the Movies.' I had pre-taped enough shows to get me through six weeks of surgery and recuperation. The doctors took a fibula bone from my leg and some tissue from my shoulder to fashion into a new jaw. My tongue, larynx and vocal cords were still healthy and unaffected."

Ebert said the early optimism ended when his carotid artery ruptured and further surgeries to reconstruct his jaw failed.

"There was no particular day when anyone told me I would never speak again; it just sort of became obvious."

Ebert said that for a while, he communicated by writing in notebooks, and then he used a computer voice he found online, one with a British accent that Chaz dubbed "Sir Lawrence." But he eventually settled on the Alex voice.

A company in Scotland was able to create a computer voice that sounds the way Ebert did before he lost his ability to speak. The voice was generated through processing many hours of tapes of Ebert talking, including his verbal sparring with fellow critic Gene Siskel on their popular movie show.

TED.com: Google's driverless car

Still, the voice he put to the test at the TED conference was the impersonal "Alex."

"The ultimate test of a computer voice is whether it can tell a joke like Henny Youngman," Ebert said.

He went on to tell this story:

"A guy goes in to a psychiatrist. The psychiatrist says, 'You're crazy.' The guy says, 'I want a second opinion.' The psychiatrist says, 'All right, you're ugly.'"

Ebert recalled being sent as a beginning reporter, 50 years ago, to the computer lab at the University of Illinois in his hometown of Urbana. A number of breakthroughs, including the first Web browser, were developed there, and a stunning series of innovations in computer technology has followed around the world.

"All of this has happened in the blink of an eye. It is unimaginable what will happen next. It makes me incredibly fortunate to live at this moment in history. ... We live in the age of the internet, which seems to be creating a form of global consciousness. And because of it, I can communicate as well as I ever could. We are born into a box of time and space. We use words and communication to break out of it and to reach out to others."

He added, "For me, the internet began as a useful tool and now has become something I rely on for my actual daily existence. ... I feel as if my blog, my e-mail, Twitter and Facebook have given me a substitute for everyday conversation."

TED.com: Open-sourced blueprints for civilization

"When you see me today, I look like the Phantom of the Opera," Ebert said, as Chaz immediately broke in to say, "No, you don't!" She had to pause in the midst of the speech to regain composure.

"It is human nature to look away from illness," Ebert added, explaining that making friends for him is now much easier online, where his blog and Twitter feed draw wide readership.

"We don't enjoy a reminder of our own fragile mortality. That's why writing on the internet has become a lifesaver for me. My ability to think and write have not been affected. And on the Web, my real voice finds expression. I have also met many other disabled people who communicate this way. ...

"So I have not come here to complain. I have much to make me happy and relieved. I seem, for the time being, to be cancer-free. I am writing as well as ever. I am productive. If I were in this condition at any point before a few cosmological instants ago, I would be as isolated as a hermit. I would be trapped inside my head. Because of the rush of human knowledge, because of the digital revolution, I have a voice, and I do not need to scream."