“Bob Newhart’s screen persona is that of a hesitant, somewhat confused man.”
I think it was when Newhart was on Craig Ferguson and he talked about that.
“It’s not a stutter - it’s a stammer. I was asked once to say my lines without the stammer. I told them “I could - but why would I? I own three homes because of it!”
The last episode of Ferguson’s late night show honors Bob Newhart and has a surprise at the end.
https://www.youtube.com/watch?v=XaEQRYeAF9w