Charley Douglass was the first guy who could make anyone laugh at the push of a button. The sound engineer invented the laff box and the laugh-track technique, which was quickly adopted by television in the 1960s and named "sweetening." The laff box was a typewriter-like machine that could produce a specific type and sequence of laughter needed for a particular situation. It operated like an organ, with Douglass using the keyboard to select the style, gender, and age of the laugh needed while using the foot pedal to control the length of the track.
Today we can see the inner mechanisms of the box, but at its birth it was called "the most sought after but well-concealed box in the world," as Kottke notes. No one but Douglass and his immediate family members knew what the inside of the laff box looked like, which added to its mysterious appeal. Inside the machine were exactly 320 laughs, including chuckles, giggles, and boisterous "belly laughs," on 32 tape loops. Each loop contained 10 individual audience laughs, spliced end to end, whirling simultaneously. Since the tapes were looped, the same laughs would play in the same order every time. So if you've ever experienced deja vu hearing an audience on TV roar in laughter, chances are you've probably heard those laughs before — many times.