Garfunkel's college roommate, Sandy Greenberg, wrote in his memoir that the song reflected the strong bond of friendship between Simon and Garfunkel, who had adopted the epithet "Darkness" to empathise with Greenberg's sudden-onset blindness.

“We were really best friends up until Bridge Over Troubled Water,” he shares, according to People. “[Afterward], it didn't have the harmony of the friendship … that was broken.” Simon contends that Garfunkel accepting a role in the 1970 film Catch-22 played a major role in the divide between them.

Simon had started writing “The Sound of Silence” late in 1963, possibly as a response to the assassination of John F Kennedy, a hero of his, on November 22. He took his guitar into the bathroom where he liked the acoustics and, as was his habit, turned off the light and sat there playing.