Romà Gubern in the introduction to Octubre (conference in Juan March foundation) explains some of the changes in the cinema with the sound arrival.
He explains the problem of the “phonogenic”. Some artist has good appearance but a unpleasant voice. Others were foreigners who were unable to learn English. In France, a multitude broke a cinema because they don’t understood the film in English.
The first film, The Jazz Singer, was a film plus a disk. The synchronization was very difficult. If you cut the film the sound was disaccording. The Warner Brothers have a Radio Broadcast. They apply the radio techniques to the films to solve this kind of problems. When the sound was simultaneous to the image, the problem was the noise near the camera. The solution was surrounding the camera. Now the problem was the weight of the camera: it seems impossible to make a “travelling”. It has been very well explained in Singing on the rain.