With the invention of the photocell and the cathode ray tube in the late nineteenth century, analogue media techniques were introduced that made it possible to transform sounds and images. The photocell as an image to sound converter played a central role in the development of sound-on-film techniques. As early as the 1930s, this potential for transformation was also artistically approached: optical sound not only represented the first effective process for the direct synthesis of sounds but also provided the opportunity to make drawn or recorded graphic elements audible, while at the same time observing them in the moving image.

With the help of the cathode ray tube as an electronic image generator it is possible to transform sound into images. As an image generator in the oscilloscope and television, it served to simultaneously transform acoustic signals into moving images in early video experiments of the 1960s. The specific characteristics of these audiovisual transformation processes were increasingly considered to be fundamental prerequisites of art production for the eye and the ear. This demonstrates clearly that technical audiovisuality has its own very distinctive way of interacting with the senses, and generates convergences of sound and image that differ from synesthetic correlations and structural analogies.