Even when filmed in front of a (responding) audience, a lot of shows like GG do 'doctor' the laughter somewhat. They all have 'warm-up' comics who put the audience in a relaxed mood prior to taping, and there are "applause" or "laughter" signs that light up to cue the audience when to laugh if the show needs the help. If necessary, they will 'sweeten' the finished recording with extra "canned" laughter, but in most cases it is not needed. Excessive laughter is often removed, since it interferes with the run-time of the episode. Some shows (especially talk shows) will actually cue the audience to react in some way (gasping, cheering, etc.), then record it to drop the sound effect into the show at another point, which is fake as hell but at least it happened during the recording session.