Optophones

Sound device in which a photoelectric cell is used to scan a text, which then produces electric signals that are converted into audible sound. The instrument today is generally used to enable the blind to read, although the device had its origins with the inventions of Austrian artist and Dadaist Raoul Hausmann in the 1920s, who was preoccupied with unifying the senses, and changing light into sound. It was patented in 1935 as a "calculating device".