In the second half of the nineteenth century, processes were developed and devices built that enabled sounds and moving images to record themselves over time and then be played back: gramophone and film. This is the starting point of a history of technical audiovisual media in which a central problem of the relationships between image and sound they involve is a temporal one; more precisely: one related to establishing the simultaneity of seeing and hearing; or formulated as a technical problem: the synchronization of sound and image. A look at the prominent historical points with respect to the technical interconnection of image and sound media — from Edison’s Kineto-phonograph to digital audiovisual formats — shows that the individual technical media for image and sound involved change, as do the methods of their synchronization. As the contractual partner changes, so too does the audiovisual contract.