Their iconic "thumbs up" was a badge of honor for any director to seek and then cherish.
But life has since dealt Siskel and Ebert a very serious thumbs down, reports CBS News correspondent Mark Phillips.
Siskel died in 1999, and repeated cancer surgery has left Robert Ebert with no lower jaw and no voice box.
Ebert has remained determined to continue his work, despite the obvious disability for a performer with no voice.
In the computer age, though, anything's possible - as renowned physicist Steven Hawking, who has muscular dystrophy, has shown. Hawking has used a voice synthesizing program for years. It may work for discussing science, but Ebert needed something with a little more feeling.
On his Web site he said he was experimenting with some off-the-shelf voice software, and he even grew fond of one called "Alex" that made him sound British, but the voice he was really trying to find, was his own.
Enter the whiz-kids from a company called CereProc in Edinburgh, Scotland, who have taken voice synthesis to a new level.
Matthew Aylett, one of CereProc's programmers, explains how his company has created software which allows them to take old audio of a person's voice, "chop it up into tiny pieces," and then use those individual pieces to recreate the individual's own unique sound.
"Although there are thousands of words in the English language, there only about 45 or so sounds," Aylett told "The Early Show".
So they have the ability to recreate a voice - but where do you find the old audio?
In Roger Ebert's case, it was from a series of DVD commentaries he'd done years ago on classic movies like Casablanca.
Using those old bits of speech, Aylett and his coworkers have given new life to Ebert's voice.
"He was very excited when he first got the voice from us," says Aylett, adding that Ebert nicknamed his new-old voice, "Roger Junior."
Unlike Hawkings, Ebert will even be able to tweak the intonation of his digitally-produced alter-ego after the software generates an audio file, adding inflection or emphasis where he likes.
Ebert new digital voice was to be revealed later Tuesday.