Here's a sound cartoon from 1924, a precursor to the Fleischers' "Screen Song", complete with the (unheralded) famous bouncing ball. It was an experiment that the always inventive Fleischers -- Max had invented rotoscoping -- were trying out. Sound films were in the air, with two or three competing systems in experimental form; these films played with their soundtracks at a small theater chain that the Fleischers co-owned with Lee DeForest; they used his talking picture system.
There had been attempts to make talking pictures from the very beginning. When Edison announced his experiments to make moving pictures a reality, he envisioned linking them with the phonograph. What delayed the widespread introduction was the lack of a system to reproduce the sound loud enough to fill a theater with hundreds of people. DeForest had come up with a system based on his invention of the triode.
There had been attempts to make talking pictures from the very beginning. When Edison announced his experiments to make moving pictures a reality, he envisioned linking them with the phonograph. What delayed the widespread introduction was the lack of a system to reproduce the sound loud enough to fill a theater with hundreds of people. DeForest had come up with a system based on his invention of the triode.