The story of the invention of canned laughter and how it transformed television.
In May 2003, one of the biggest influences on television production, Charles Douglass, died at the age of 93.
A CBS engineer on live shows, in 1953 he developed a device which would change the way we experience television.
It looked like an enormous typewriter and he called it the Laff Box.
The original Laff Box stood over two feet tall and contained a set of audio-tape loops which featured recordings of laughter taken from episodes of the Red Skelton Show and a Los Angeles performance by Marcel Marceau.
A sound editor would press different buttons for different types of laugh and foot pedals were used to control the timing and duration of laughter.
The box was originally used to fill gaps in the sound of early tv shows when scenes had to be reshot after the audience had left the studio.
But eventually artificial laughter would be used throughout programmes, especially where audiences didnt laugh at the appropriate moments, or, if they did, not heartily enough.
And thus was born what became known as canned laughter.
Canned laughter was originally regarded as a democratic device, connecting audiences to the often glamorous world of television sitcoms.
But the ease with which the Laff Box added hilarity to even the weakest shows led to its over use and to the belief that, without canned laughter, a show would not be regarded as funny.
Today, laugh machines are the size of a lap top computer and are still much in use.
With contributions from Douglass son Bob, who has inherited his fathers post production business, and from producers and critics in American and British television, this programme tells the story of Charles Douglass, the Laff Box an.