The late ’50s brought us a revolutionary new kind of comic performer, what Time magazine and others called “the sick comedians.” Lenny Bruce, Mort Sahl and Mike Nichols and Elaine May were at the forefront exploring politics, sex, race, urban neurosis and the post-war, Cold War jitters of a new nuclear age. Their tone was dark, satirical, even derisive.

None seemed closer to home, however, than Bob Newhart.

A former accountant, Newhart’s mild, halting manner was pitch-perfect for an age in which the generic might of the giant corporation wrapped its tentacles around the plaintive working stiff, and the institutional duplicities of the advertising world confused a decent guy’s everyday relationship with the truth.

“Abe Lincoln vs. Madison Avenue” is a perfect example. In it, an ad man and speechwriter phones Lincoln: “Hi Abe sweetheart … how’s Gettysburg? ” before cautioning against changing his image, cutting his beard. “Don’t type the address, Abe. Remember, back of the envelope.”

With those lines, first heard on his 1960 debut album, “The Button-Down Mind of Bob Newhart,” Newhart captured the nation. The album went to the top of the Billboard chart and opened up a career, not just in standup, but in TV and the movies, in which his stammering, everyday demeanor and slightly hang-dog look are still as disarming as they were 50 years ago.

“There was a lot of regional humor when I was growing up,” Newhart says. “There was also a lot of standard mother-in-law and take-my-wife jokes. But a sea change was going on. The college kids wanted something different. The Ed Sullivan show was a town hall for a national audience. I knew that, to be onstage, I had to develop my craft. It took time. It’s one thing to do a monologue, but when it comes to sketch comedy, comedy with other voices, I had to learn to listen to my own voice in a different way.”

He’s been a good listener, and that voice has always worked its nervous way between basic good sense and the fear of offending someone who’s lost sight of it. Born in Illinois, Newhart credits his Midwestern roots.

“A lot of comedians come from the Midwest,” Newhart says, citing Johnny Carson, George Gobel, Jonathan Winters and Shelley Berman, with whom Newhart shares the technique of a one-sided telephone conversation. Richard Pryor, born and raised in Peoria, Ill., is the surprising object of Newhart’s highest praise — surprising because they’re so different.

“I’m glad he got the first Mark Twain Award for American Humor,” says Newhart of a prize he won himself in 2002, to go with three Grammys, a Peabody and several Emmy nominations. “In his way, (Pryor) was doing exactly what Mark Twain was doing when he made a universal experience of life on the Mississippi.”

Newhart has made 17 films and numerous TV appearances (he hosted “The Tonight Show” 87 times) and has been a sure bet for celebrity roasts, particularly during the Rat Pack era. On one, featuring his close friend Don Rickles, he said, “I’m sure Don would take umbrage at my remarks if he know what the hell ‘umbrage’ meant.”

During the ’70s, “The Bob Newhart Show” was one of the great excuses to stay home on Saturday night. It ran for six seasons; “Newhart” ran for eight more. Then he went back on the road. At 83, he’s still going out.

“The thing that happens, and this is universally true, is that the more successful you are, the more you’re cut off from the source of your material,” he says. “You’ve got to continually work it. You’ve got to concentrate on making your connection with the audience. Travel is terrible. Your luggage gets lost. But there’s nothing like the right performance before the right audience. I mean, how could you ever tire of making people laugh?”