Anyone interested in reading about one of the instrumental figures in creating synchronized movie sound would do well to check out A Tribute to George Groves-The First Sound Man.
"...George Groves could boast numerous achievements. During the 1920s as a young engineer at Bell Laboratories in New York, he played an influential role in developing the sound-on-disc technology that facilitated sound motion pictures.
In 1925 Warner Brothers acquired the Bell apparatus and created the Vitaphone Corporation. They then utilised George's expertise as a sound recordist, production and music mixer on many of their early sound films including Don Juan, The Jazz Singer, The Singing Fool, Lights of New York and The Desert Song."
The truly wonky among you will surely want to dive into the site's early film sound timeline.