Adding to the fun of this is that Murrow may-well be the most famous voice in U.S. radio history because of his renowned "This is London" broadcasts during World War II. And so clearly the challenge in the game here was to disguise that voice. And Murrow seems to be actually having great fun doing voices. (Fortunately, there's a lot of talk after the game end, so we get to hear a lot of Murrow as Murrow.) Further, he was known as someone who was VERY serious -- famously getting into arguments with management to protect his news broadcasts and commentary which were often controversial -- and he clearly has a good sense of humor on the show here.
(As it happens, for a personal reason I know that those arguments with management were a real thing and not just rumored. When I was at Northwestern, I did an independent research study with a new professor who had just joined the Medill School of Journalism there, a fellow named Sig Mickelson. As it happens -- though my crossing paths with him wasn't coincidental, indeed it was probably the main reason I wanted to do the independent research study -- Mickelson had been the president of CBS News when Murrow was there, probably in the late-50s / early 60s. I had a chance to talk with him about Murrow a bit, which was a joy, and while Mr. Mickelson admired Murrow's work a great deal, he noted that he and Murrow often butted heads, and it was a difficult relationship.
(If you saw the movie, Good Night, and Good Luck, about the See It Now broadcast on Joseph McCarthy, Jeff Daniels plays Sig Mickelson in the film. The two look nothing alike. Mr. Mickelson looked more like the character actor John Randolph, who played Tom Hanks' grandfather in You've Got Mail.)
This is from very early in the TV show's run, airing on December 7 (a notable day in history), 1952, If you want to jump right to the segment, it starts at 16:38. And even though his appearance is just 7-1/2 long, you'll notice that he still can't go that long without his trademark cigarette.