When I watched the Brady Bunch as a youngster, there was one particular deep guffaw that always caught my attention. I knew the laughs were pre-recorded but always assumed that there was just a laugh track tape and they'd press play at the appropriate times. I liked (and still like) the faux communal experience that laugh tracks provide when watching the Bradys, Bewitched, the Beverly Hillbillies, and other great vintage sitcoms from the 1960s an early 1970s.
Turns out, that the rise of the laugh track was due to Charles Douglass (1910-2003), a Navy-trained electronics engineer/maker who went on to build a custom "Laff Box" of several dozen tape loops triggered by keys and dials. After its initial use on the Jack Benny Program, the machine, officially called the "Audience Reaction Duplicator," took the TV industry by storm. Douglass "played" the Laff Box like a proto-sampler and for years had the monopoly on TV laugh tracks. It was a process that the TV show producers and Douglass himself liked to keep secret.
It wasn't until 1992 that Douglass and his pioneering work at the intersection of media, psychology, and technology was recognized with a lifetime Emmy award for technical achievement.
For the whole story on Douglass and the Laff Box, don't miss this episode of the Decoder Ring podcast.
And here is an Antiques Roadshow segment appraising a Laff Box.