Already famed for the memorable thumbs-up/thumbs-down movie summaries he delivered alongside former colleague Gene Siskel, Roger Ebert has cemented his reputation as one of the world's best known film critics with his wholehearted adoption of the internet.

After several cancer surgeries left the gregarious critic unable to speak, the longtime print journalist — who in 1975 became the first film writer awarded the Pulitzer Prize for criticism — has bloomed online and via micro-blogging application Twitter.

"These days, the internet is my bridge to society. I now know how social the social media really are," he told Jian Ghomeshi on CBC Radio's Q, through text-to-voice software.

During a recent stop in Toronto for the Toronto International Film Festival, Ebert discussed his new memoir, Life Itself, and how his health challenges have changed him.

"Now that I can't speak, writing gives me a voice and an outlet. It absorbs me. It allows me to feel useful. It saves me from becoming trapped within myself," Ebert said.

"There's no use in using rose-coloured glasses: it has been devastating. I was extroverted. It has turned me inward. I could always make my voice heard in a room. Now, I am sometimes just left sitting in a corner. People have a limited amount of patience for reading my notes. I can use this computer voice and it's very useful in a situation like this, but it has its limitations."