For the past 50 years, showbiz vet Maurice H. Zouary has been a man with a mission: Greater recognition for Lee DeForest, a scientist whose inventions helped usher in the sound era. Zouary, a multi-hyphenate from a vaudeville family, first learned of DeForest’s sound reels while investigating claims of pioneering sound work by William Fox and Warner Bros. In 1957, Zouary discovered proof DeForest was processing sound on film during the early 1920s — at least seven years before “The Jazz Singer” — in a rare film library he operated. Since then he has tirelessly crusaded on behalf of DeForest. This tome chronicles his findings about the early sound era and the advent of talkies.