A classic documentary from the 1980s goes behind the scenes of how laugh tracks were added to television shows. As it turns out, the laugh track was developed by sound engineer Carroll Pratt, who helped develop the “laff box” with fellow sound engineer Charley Douglass in the late 1950s. By the 1980s, Pratt and his brother started Sound One Studios, which provided canned laughter to most US sitcoms of that era.
Pratt began doing “laugh sweetening” in the late 1950s with Charley Douglass, developer of the original “laff box” sound effects device. By the 1980s Pratt’s company was providing prerecorded laughter for about 80% of all sitcoms on TV in the U.S