 The sound reaching this ribbon would be converted into light by the shivering of the diaphragm, focusing the resulting light waves through the slit, where it would be photographed on the side of the film, on a strip about a tenth of an inch wide.In 1908, Lauste purchased a photographophone from Ruhmer, with the intention of perfecting the device into a commercial product.Though sound-on-film would eventually become the universal standard for synchronized sound cinema.