On TV talk shows that are taped, when they say “Hold that thought, we have to cut to a commercial break” and cut to a break, do they actually break on during the taping of the TV show or do they immediately start up again in the studio by saying “Welcome back to the show…” and no time elapses?
I’ve never been to a taping, and I’m not sure if it’s true of all talk shows, but I’ve seen episodes of Letterman, say, where after a commercial break he’ll say something like, “During the break you were telling me about…”. Also, the band usually starts playing a song before they go into the break and finish it when they come back, and sometimes you’ll get a few commercials and then the show’s logo will pop up with the music in the background and it’ll be right in the middle of a song, then you’ll get a few more commercials and the show will come back on. So in some cases, at least, they actually stop and wait for the break to end. Also (though I’m loathe to admit it) I’ve seen episodes of Jenny Jones or Jerry Springer (not talk shows, I know, but same basic premise) where they’ll come back from commercial and show footage of something that happened during the break if it’s sufficiently sensationalistic.
I’ve never been a member of a talk show TV audience, but {mumble, mumble} years ago I went to a taping of Match Game and they did, in fact, pause the “action” for several minutes - enough time for commercials to have run - before resuming taping of the game. I have no idea if they still do it that way, though.
I have sort of been to a TV taping. 
OK, so it was definitely a TV taping, but not one that would leap immediately to people’s minds when asked to name talk shows. Namely, it was Crook and Chase – back when they were still on the Nashville Network and still taping in Nashville.
IIRC, the taping was pretty much the length of the show. The breaks were the length of the commercials that would run there, and the crew seemed to use it as time to “reset” – to get cameras back in best position, to touch up makeup, to adjust notes, to adjust lighting rigs, and to set up for guests.
I understand that Letterman, Leno, and Conan do pretty much the same. In fact, I think that’s what’s meant by “taped live before a studio audience” (which seems redundant). I think that’s what it means – that what you’re seeing on TV is pretty close to what you’d see were you there in person.
I think Letterman’s set even has a clock set to “showtime” – that is, that is set to 11:35 when the show begins taping at 5:30 or so (not sure when those tapings begin), thus allowing the host and all involved with the show to keep track of what time of night their antics will be televised. (I’m not sure of that – and not sure why it’s in my head that it is that way.)
Now, I suspect that extended setups may run a commercial break long – for instance, when Leno is setting up for a skit or when Letterman’s stage is being set-up for some gag or act.
That’s why it’s fun to watch Saturday Night Live – because you know those actors are running to quick-change booths to get into the next costume!
In most cases, they “step down,” which means that the technicians stop the tape machines that are taping the show, they re-adjust camera angles, bring out new guests, and generally tidy up or fix what need’s fixing before they start up taping again. If you were to view one of these shows as they are fed to the TV stations, you would see the host pitch to a commercial break and then 2:02 (2 minutes, 2 seconds) of black after which the show would start up again.
TRIVIAL MINUTAE: The 2:02 is what professional TV host Chuck Woolery is referring to when he pitches to a break and says “We’ll be back in two and two.”
Well, I went to Letterman once, and they definitely took the break during the commercial time. Usually, they’d just talk a little, nothing much, then the freaky cue guy comes out and tells you to cheer for the return from break.
Jman
I’ve been to a taping of Jonovision, and they paused for approx. 15 seconds, to take a drink of water etc.