markrichardb: I thought that was filmed in front of a live audience. You can even hear some of the comments from the crowd:
https://www.youtube.com/watch?v=tYifMohjv54 The laughter of live audiences is - AFAIK - still always intensified with archival recordings of laughing crowds (at least in TV shows, not recordings of actual live acts) and it's common to refer to it as a laugh track no matter whether a live audience was present or not. Plus you always record as much as possible to isolated tracks anyway for easier editing (and especially in the US it's - AFAIK - standard procedure to re-record every bit of dialogue after the original performance), so even if you're going really technical, ultimately a show with crowd reactions has a "laugh track".