I think this new laughing guy character that Artie does is a rip of Jimmy's Ted character. The way the voices sounds, the corny senses of humor, it just seems like Artie is trying to copy Ted.
There is tape of artie doing this voice many moons ago that I came across listening to clips on youtube. Something like Richard thought a bit was funnier than it was and he went off on it.
I'm pretty sure all of them are doing impressions of a skit from many many years ago anyway.