[tlhIngan Hol] any Seinfeld fans out there?

The pun behind {Dut} "slam down" seems to be a Seinfeld stand-up monologue where he complains that he doesn't like mobile phones because you can't slam down the phone any more, but instead have to [mimics pressing a button on a device while making a "doot" sound]. He's told the joke multiple times, and in later versions he does a swipe (for an iPhone). I've seen a version where he does the "doot", and I think it must have been from the "stand-up" portion of an episode of the Seinfeld show (because I haven't seen a lot of his other stuff). Does anyone know the episode? (The only videos I've located where he tells that joke are from the iPhone swipe version.) Thanks. -- De'vID