Does technology exist to make dialogue by the same person in two dif voices seem like it’s so close to overlapping that they must be different people?
Kevin Mathews (formerly of Chicago; now in Grand Rapids) and the character “Jimmy Shorts” make me wonder … does anybody know if they are one and the same?
If the dialog is pre-recorded and edited, this can be done easily. If it’s being aired live it’s not as easy, but not necessarily impossible.
That being said, don’t assume that just because you’re listening to a “live” show on the radio that every bit of dialogue is really live. A lot of DJ’s pre-record some of their bits to incorporate into live shows.
They can pre-record it in studio and make it sound live. So, yes, it’s very easy to do. They could pre-record 1 of the voices, and do the other live. So, Yes.
The technology is easy to do. I have a free version of Audacity that would work easily for that. It would have to be scripted, and pre-recorded to use on the air. Don’t know about the DJ you refer to, tho.
damn, FatBaldGuy beat me to it. 
Any true KevHead knows that Jimmy is the only real person and Kev, Devon, and the rest are all puppets. 