Børge Ring writes:
From Laugh-O-gram to Laugh-O-meter...
Walt Disney's intense study of audience and what made an audience react lead him during the early 30's to invent and build what he called a Laugh-O-meter. It was a sound recorder that registered the laughs of a cinema audience during the projection of a short. During the projection it ran in sync with the film and, counting seconds (or feet?) delivered a report on which seconds of the film brought laughter and to what degree. A secretary wrote out the report in typescript across a barsheet of the film.
19,5 through 37 Belly laff
48 through 62 Titter
and so forth
The machine was capable of backlash. If a film was unsuccessful the secretary would write "slight titter" or "some coughing."