1.1 Historical development of the image-sound recording

Looking back, two different technological strategies can be defined with which the sound backing a visual image can be analogically and synchronically recorded and reproduced. Image and sound have either been recorded separately on different mediums or recorded together on one medium in order to be played back.

In the early days of film history however, image and sound were separate, and phonography and cinematography had to wait two decades before they could be united. Initially, Edison developed sound recording and playback using a phonograph, and in 1889 he was able to link the appropriate images synchronously, playing them back using the Kinetophone. The sound film would finally establish itself, its technological development via needle sound, optical sound, and magnetic sound paved the way for today’s digital sound. In the case of needle sound, the recording was played from a roll or a record that was separate from the camera, so the different playing speeds of the image and sound carriers could not be synchronized precisely. Through the use of optical sound it finally became possible to create a synchronized image-sound relationship on one single recording medium, on which optical patterns next to the edge of the image formed parallel corresponding sound waves. However, in the early days of recording optical sound the camera became static because it had to follow the microphone recording the sound and this had a detrimental effect on the multiperspective flexibility of movement within the space that had previously been achieved in silent films. Because the sound and image had to be recorded on the film strip with a timeshift, in the subsequent montage, the overlapping sound from off-screen to on-screen and vice versa could only be operated within limits. The potential for creating tension in the off- and on-screen sound dramaturgy therefore required that the sound be assembled separately from the image. The next analogue attempt at realizing a frame-precise synchronization of image field and sound field was using magnetic sound. Here, a separate audiotape was used for the recording, which in the form of a welded magnetic edge track enabled a synchronized playback. In the case of a digital data storage medium (tape and/or hard discs), the image and sound can be saved together, both when recording and for the playback.

Irrespective of whether they are being recorded or stored for projection, in all the procedures the sound and image are processed separately in an intermediate step — montage and sound mixing — while digital technology, which leans more towards mixing, is increasingly dissolving the boundaries and traditional division of labor in sound work. As a result of the binary unification of bits and bytes in the images and sounds in the computer-aided practice, image and sound editors, sound designers, film composers, etc. no longer have clearly separated areas of competency. However, we should first take a closer look at what is common practice in recording, processing, and playback.